Development of PVC-based compositions: Specific gravity of ingredients. Raw materials pvc Methods of obtaining a composition based on pvc

PVC plastics are widely used in the footwear industry. They are used to make shoes for the spring-summer range, for example, the soles of casual shoes, walking shoes and clogs, beach shoes, inexpensive sports shoes, house slippers, soles and tops of rubber boots for various purposes. There are other uses for PVC in the footwear industry.

Various companies are engaged in the production of footwear using PVC - both large enterprises equipped with modern equipment and private traders who have organized the casting of soles and sewing slippers in "garages". Casting is sometimes used from a powdery "charge" (a mixture of PVC, DOP and other additives), which leads to the production of products of low quality.

Usually, high competition leads to higher quality products and lower prices. Unfortunately, competition in the Russian PVC-compound market and the resulting price reduction is often accompanied by a decrease in product quality. Manufacturers of both plastic compounds and footwear are going to reduce the quality, primarily in the least critical sectors of inexpensive footwear "with short life cycle»- slippers, summer shoes, etc. In the end, the consumer who buys shoes of inadequate quality loses. However, in the conditions of limited payment capacity of most consumers of PVC footwear, the production of low-quality plastic compounds will (unfortunately) continue.

Problems of the production and use of plastic compounds

The main components of the compound are PVC resin, plasticizers, stabilizers, dyes and other additives. Sometimes fillers are introduced to reduce the cost.

PVC resin

Manufacturers of plastic compounds, of course, have a "rating" of the quality of resins from various manufacturers. Without considering it, we note that the most common C7058M resins on the Russian market of shoe plasticates actually have slightly different molecular weight values, and the highest weight is characteristic of the resin produced by Azot OJSC (Novomoskovsk), therefore, the plastic compound based on Novomoskovsk resin has low fluidity (PTR).

Plasticizers

Despite the protests of the "green" and a number of doctors, the most common PVC plasticizer both in Russia and abroad is DOP (di- (2-ethylhexyl) phthalate). It has an optimal combination of properties and is relatively cheap. DOP belongs to the so-called primary plasticizers. The use of other primary plasticizers is limited by their price and there are very few in Russia. In addition to the primary ones, there are also secondary plasticizers that are not used independently, but can partially replace the primary ones. The price of secondary plasticizers is naturally lower, so many manufacturers try to use them. Classic examples of secondary plasticizers in Russia are chlorinated paraffins, as well as EDOS and its analogues. Making products cheaper (in comparison with DOP), these plasticizers impair a number of properties of plastic compounds.

Chlorinated paraffins increase the density of the compound and reduce its thermal stability. EDOS is a mixture of isoprene production by-products, its composition is unstable, and its volatility is noticeably higher than that of DOP. In addition to EDOS, there are currently a number of its analogues on the market, the characteristics of which are even slightly worse. When these plasticizers are introduced into the composition (especially in large quantities), problems with the processing of plastic compounds, porosity, color stability and sweating to the surface can arise.

Based on the analysis of our own results, products of other manufacturers and consumer reviews, we can say with confidence that the compositions obtained using only DOP as plasticizers have the best quality. The use of secondary plasticizers should be minimized, otherwise the quality of the plastic compound and the working conditions with it deteriorate.

Excipients

Fillers are cheap substances, the main task of which is to reduce the cost of compositions. One of the most common fillers is chalk. It can only be introduced with twin-screw extruders that provide good mixing. With the introduction of a small amount of chalk, the physical and mechanical properties practically do not change, but the density increases.

Additives

Stabilizers are essential components of PVC compounds. The manufacturability (processability) of the composition and the service life of the final product largely depend on their nature and quantity. An indirect characteristic of the successful selection of these additives is such a characteristic of the compound as thermal stability. Colorants can play numerous roles. In addition to the main one - coloring the composition in the desired color - they can also increase lightfastness (soot is one of the best light stabilizers) or reduce it. The selection of dyes is difficult because PVC is not inert to many of them. The cheapest and most durable dyes - inorganic pigments - usually produce dull tones. Bright and vibrant colors can be obtained using organic pigments and dyes. Unfortunately, they are less strong and durable than inorganic pigments. In addition, the domestic industry produces a very limited range of organic pigments compatible with PVC. The use of imported pigments increases the quality, but increases the cost of the products.

Approximate composition of compositions for shoe shells and heels

In world practice, plasticized compositions based on PVC are widely used in the manufacture of footwear. Approximate formulations of plastisols for shoe casing and heel are shown in Table 1.

A complex composition was used as a stabilizer, which includes salts BA, Cd, Zn. The plasticizer in the heel composition is butyl benzyl phthalate. Which well wets the PVC resin and lowers the melting point of the plastisol. To increase the stiffness of the heel, a monomer of the X-970 type, capable of polymerizing in the presence of a catalyst (tert-butyl perbenzoate) at room temperature, is introduced into the composition. Cobalt naphthenate acts as a cocatalyst, accelerating the polymerization of the heel composition.

Table 1: Approximate Composition of Shoe Shell and Heel Compositions

Shell composition I	Shell composition II
*Components*	*Components*	*Mass fraction, parts per 100 parts of resin*
Microsuspension resin	Microsuspension resin
Resin M-70	Resin M-70
Mixture of plasticizers	Butylbenzyl phthalate
Complex stabilizer	Monomer X-970
Defoamer (PMS-100A, PMS-200)	Complex stabilizer
Pigments, additives, modifiers	tert-Butylperbenzoate, PMS-300, pigments
Viscosity (Brookfield) mPa * s	Viscosity (Brookfield), mPa * s
Gelation time tzh, s	Gelation time tzh, s
Density, kg / m3	Density, kg / m3

PVC compounds and powders for manufacturers of profiles and electrical cables. We make plastic profiles according to the customers' sketches.

Domestic and foreign mixing plants offer Russian manufacturers of plastic profiles and electrical cables their high-quality PVC compounds and powders.

The factories have been producing these products for many years, have extensive experience in developing special formulations for the required customer requirements with specified hardness, color and other properties. The factories use only high quality European resins, stabilizers and additives as raw materials.

List of products (granules or powders):

PVC compounds for the production of rigid profiles (13 standard colors). It is possible to produce electric boxes, finishing building profiles
PVC compounds for the production of soft profiles, PVC, combined formulations containing PVC and rubber. It is possible to produce seals, cooling profiles
PVC transparent PVC compounds
powders for the production of foam profiles (13 standard colors). You can make skirting boards, platbands
PVC compounds for the production of plastic windows
PVC compounds for the production of high quality wall panels
PVC Compounds for Injection Molding Machines
PVC compounds for the production of sheaths and insulating layers in the production of electrical cables
PVC compositions containing antistatic agents for the production of linoleum floor coverings.

The compositions are resistant to UV radiation, frost-resistant and shock-resistant formulations are also available.

The plant develops special recipes for the customer, the minimum batch is one ton.

We make PVC compounds and mixtures for both single-screw and twin-screw extruders.
ABS sheets with a thickness of 1 to 6 mm, maximum width 2.5 m
Polystyrene sheets with a thickness of 2 to 6 mm, maximum width 2.5 m
ABS compositions (extrusion grades)
Polycarbonate (extrusion grades).

Recipe	Type of raw material	Shore	Application
PM 401	granules	65	production of seals and hoses, sustained. -40 °
D 2448	granules	75	seals -40 °
PM 815	granules	100	for casting
KRISTALLO	granules	100	hoses and seals (transparent)
GFM / 4-40-tr	granules	63	sealant for windows and doors
PVC 7374 PRE	powder	100	for the production of shockproof profile
PM 933	granules	82	seals for refrigerator doors
G 2454	granules	75
PM 303	powder	100	for production of electric boxes
VM 633/12	granules	82-90	cable insulation layer
VM 635/90	granules	82-90	cable insulation layer
KM 601/10	granules	82-90	cable insulation layer
EM 213/10	granules	82-90	cable insulation layer
PM 911	granules	92.5	for the production of thresholds
PM 949	granules	92.5	for the production of thresholds
PM 104	granules	100	used for the production of pipes
PM 809	granules	100	for the street
PM 1005	powder	40-50	foamed
PM 1002	powder	40-50
PM 1008	powder	40-50
KRISTALLO BZ 75	granules	74
KRISTALLO BZ 90	granules	90	for production of flexible hoses and seals (transparent)
PM 806	powder
PM 950	granules	87	step pads, plinth tape, soft corners, thresholds. antistatic
PM 313	powder	100	for wall panels and sheets
ML 3290
PM 953	granules	81	for the street

Every year the fields of application of polymeric materials (PM) are expanding and the requirements for the conditions of their processing and operation are becoming more complicated. The task of extending the service life of a PM product is very urgent, since during the processing and operation of PM, they are subjected to various influences, leading to a deterioration in their properties and, ultimately, to destruction. In addition to the high-molecular-weight polymer, modifying additives are necessarily introduced into the composition of PM, without which the processing of PM and the operation of products from them is impossible. These additives include, first of all, stabilizers that protect the polymer from oxidation under the influence of heat, light, radiation, air ozone, etc.

Aging PVC

The aging process of plastics is an irreversible change in their structure and composition, leading to a change in their properties. Distinguish between climatic aging, aging in the aquatic environment, in soil, soil, artificial conditions, light aging, etc. There are a lot of indicators for determining aging, physical and mechanical, electrical properties, etc.

The problem of predicting PM behavior under various conditions has not yet been resolved. A characteristic feature The destruction of PVC on heating is a progressive darkening of its color associated with dehydrochlorination - initially colorless material can turn yellow, red to dark brown - at temperatures above 100 ° C, especially when processing in the range of 160-1900 ° C. The color change is accompanied by crosslinking of the polymer. In the presence of oxygen, decomposition proceeds faster than in an inert atmosphere. The destruction of PVC can be assessed by the intensity of HCl release, but in practice it is more often judged only by the change in the color of the material. In the processes of processing unplasticized PVC compositions by extrusion and injection molding, the destruction of the material under the influence of temperature leads to a change in the color of the product, the presence of bubbles. When the polymer mass "burns" during processing, partial crosslinking occurs, as a result of which the viscosity of the melt increases. The introduction of stabilizers delays the onset of PVC decomposition, and in this period of time, called the induction period, there is no noticeable release of HCl. It is necessary that the residence time of the material in the molten state does not exceed the induction period at the processing temperature. Therefore, it is necessary to control the plasticizing time of PVC. Heat and light have different effects on changing the properties of PVC. Perhaps this is due to the active role of oxygen in photooxidation. In the process of thermal dehydrochlorination after photoaging, PVC becomes brittle, a gel fraction appears. In this case, the color change occurs after some time in the form of separate dark spots. Photo-irradiation in the case of PVC is attributed to the brightening effect. The aging behavior of plasticized PVC is determined by the properties of the plasticizer. During aging, the plasticizer oxidizes with the formation of low-molecular-weight products that do not possess plasticizing ability, easily volatilize or are washed out from the material.

Studies have shown that, depending on the type of plasticizer, not only the absolute stability of PVC-based films changes, but also the time interval that separates the moments of appearance of stiffness and brittleness in the films. Dioctyl phthalate and dioctyl sebacate, as well as some polyester plasticizers, have good stabilizing properties. The behavior of plasticized PVC under atmospheric conditions is also influenced by the type of pigment used. PVC films plasticized with dioctyl phthalate tend to lose mechanical strength faster in weathering tests when a green pigment is incorporated, compared to films containing brown pigment. When the plasticizer is oxidized, an unpleasant odor appears as a result of the catalytic activity of various pigments.

Thermal aging of polymers is studied by the composition of the destruction products by the spectral method, using isothermal conditions (using a spring balance in a vacuum, weight loss is determined, then differentiation is made by the rate of destruction), or by derivative methods.

PVC stabilizers

The task of stabilization is to preserve the original properties of polymeric materials during aging processes. In principle, polymers can be stabilized in two ways: by introducing stabilizers and by modifying PM by physical and chemical methods.

In practice, when choosing stabilizers, in addition to efficiency, other properties are taken into account: compatibility with the polymer (insufficient compatibility leads to phase separation - sweating of the stabilizer), volatility and extractability, ability to color, odor, toxicity, efficiency. In addition, stabilizers affect the processing modes and performance characteristics of finished products.

The main destructive processes in PVC compositions

Dehydrochlorination

The main requirement for PVC stabilizers by technologists is to bind hydrogen chloride that is split off during destruction (dehydrochlorination reaction). The polymerization of vinyl chloride contributes to the formation of fairly stable linear molecules, but as a result of the final reactions, tertiary carbon is also formed, due to dismutation, and the final olefin groups. These final groups are the most unstable, they act as active centers of the polymer chain and, when a certain activation energy is present, they contribute to the formation of the first hydrochloric acid molecule. After isolation of this molecule, the rest of the structure has a very active carbon at the alyl position, which allows the continuation of the reaction. The formation of polyester structures, the length of which exceeds the length of six double bonds, leads to a color change that is typical for unsaturated products, for example, carotene C40 H56.

Oxidation

At the same temperature, the release of hydrochloric acid is greater in an oxidizing environment than in an inert one. In this case, a certain saturation of the polymer leads to the occurrence of an oxidation reaction at alyl positions, as a result of which the instability of the polymer increases due to the formation of carboxyl groups. The oxidation process can be carried out in various ways, for example, through the intermediate formation of cyclic peroxides or hydroperoxides, but in all cases, oxidation leads to the formation of polyene-ketone structures. Recently, the autocatalytic effect of hydrochloric acid in an oxidizing and inert environment has been investigated. This phenomenon can be explained by the fact that the formation of iron dichlorides occurs, which themselves are energy catalysts for oxidation reactions at elevated temperatures (iron dichlorides are formed as a result of the reaction of hydrochloric acid with iron in the walls of equipment). The choice of the correct stabilizer depends on the criteria of economy and on the conditions of use of the final product (it is necessary to take into account toxicity, the presence of light sources, organoleptic characteristics and other factors). Stabilizers are added in relatively small doses, since the effect of stabilizers as reaction inhibitors is very effective in comparison with the effect of the stoichiometric ratio of the substances that take part in the reaction.

Stabilizers should be compatible with PVC and should not affect the color of the final product, in addition, the stabilizers should be free of volatiles and odor.

Of the many different types of stabilizers, organic tin derivatives, organic metal salts and epoxy semi-stabilizers are discussed below.

All types of compounds listed above react to HCl, however, HCl binding, the central task of stabilization, does not exhaust all practical requirements. An ideal PVC stabilizer should perform the following functions: bind the released HCl, inhibit (inhibit) the oxidation and crosslinking reactions, protect double bonds in PVC chains, and absorb ultraviolet radiation. The realization of all these functions is achieved through the use of a mixture of stabilizers (complex stabilizers). It should be noted that the use of two types of correctly selected stabilizers in combination with lubricants does not give a simple total effect, but many times greater than each of them separately.

One of the peculiarities of PVC processing is that heavy metal compounds are the only really effective stabilizers. All these substances are more or less toxic. The possibility of their use in PM in contact with food products and in systems of domestic drinking water supply is decided at the level of the Ministry of Health and national legislation.

Stabilizer types:

a) lead-based stabilizers
Lead-based systems were the first systems used in the plastics industry. These systems provide long-term stability, are durable, inexpensive, but they also have disadvantages: when using them, it is impossible to obtain transparent products and these systems are toxic. These include: 3-base lead sulphate - a long-lasting heat stabilizer, 2-base lead stearate and dibasic lead phosphite. Both are used as light and heat stabilizers. They are always used in combinations including calcium stearate as a lubricant.

b) stabilizers based on calcium and zinc
Calcium and zinc are used as stabilizers in packaging materials food products, that is, products that must have high organoleptic quality indicators. Thermal stabilization is provided due to the synergistic action of two components: zinc produces a short-term effect, calcium is long-term. Zinc octoates (liquids), calcium stearates are also used, but they are not as effective. Appropriate semi-stabilizers (soybean oil) are required.

c) stabilizers based on organotin compounds
These connections are universal. The disadvantage is the high cost. They stabilize well all types of PVC. Sulfur-containing organotins are extremely important thermal stabilizers. They are used to stabilize transparent, colorless rigid PVC products, mainly films, plates, the processing of which requires high temperatures. Sulfur-free compounds are effective as light stabilizers and are odorless.

d) epoxy auxiliary stabilizers
They are mainly used as synergists in a mixture with metal soaps to increase lightfastness. In addition, they increase the ductility characteristics.

Antioxidants

Phenolic antioxidants such as phenylolpropane act as light stabilizers and also inhibit the oxidation of plasticizers.

The effectiveness of stabilization is determined by the following four factors: the intrinsic stability of the polymer, the formulation, the processing method and the field of application of the finished product. The intrinsic stability of the polymer is determined by the molecular structure of the polymer (molecular weight and molecular weight distribution, the presence of branched structures, end groups, oxygen-containing groups, polymerizing components), as well as the presence of impurities. For the most part (with the exception of the structure of the copolymer), the features of the molecular structure and impurities remain unknown, however, the method of obtaining the polymer largely determines its stability.

Emulsion PVC contains residues of emulsifier (soap and sulfonates), catalyst (ammonium persulfate, sodium bisulfate) and buffer substances (sodium phosphate). Suspended PVC contains significant amounts of substances introduced during polymerization, for example, protective colloids (polyvinyl alcohol) and catalyst residues (lauroyl peroxide). Block polymerization produces the purest polymer with no catalyst residues. Auxiliary substances impair the transparency, water resistance, insulating properties and stability of emulsion PVC compared to suspension.

The stability of PVC also depends on the polymerization conditions (pressure, temperature, etc.) and the auxiliary additives used. Now the production of PVC with a given stability is being mastered.

In conditions PVC production to it are added stabilizers containing barium, cadmium, tin. When processing such PVC into specific products (films, pipes), one must firmly know how and to what extent they are already stabilized in order to make a decision on further stabilization. The influence of the formulation on the stabilization effect is mainly dependent on the plasticizer.

The commonly used phthalates and polyester plasticizers have almost no effect on the stability of PVC, while phosphites and chlorinated paraffins impair the thermal and light resistance. Light fastness is improved in the presence of di-2-ethyl-hexyl phthalate. It was found that a small addition of 2-ethylhexyldiphenylphosphate to the widespread plasticizer di-2-ethylhexylphthalate (DOP) significantly increases the weather resistance of plasticized PVC, especially thin films made of such PVC compositions. Optimum light and heat resistance can be obtained by adding 10% epoxy compounds to the formulation.

Other modifying additives

Excipients

Other formulation components that sometimes require special stabilization are fillers and pigments. For example, alumina, due to its good dielectric properties, is often used for insulating materials, and asbestos, due to its thermal insulation, is often used for floors (vinylsbestos tiles). There are a wide variety of fillers that differ in particle size and shape, manufacturing method and surface treatment.

Fillers reduce the cost of the composition, but at the same time, the tensile strength, elasticity, and abrasion resistance are reduced. Fillers with particles larger than 3 microns cause wear on the processed equipment. In Ukraine, in the CIS countries and Western Europe, natural chalk is used as a filler in an amount of up to 2%, in Italy fillers based on silicon dioxide with small particles in an amount of 0.5-3% are used.

Lubricants

In addition to effective and correct stabilization, the correct lubricant is important, which is designed to reduce friction between particles during processing.

The principle of operation of the lubricant is that molecules are introduced between the polymer chains of polyvinyl chloride, which have a certain polarity and can reduce the forces of attraction between the chains themselves. Instead of these attractive forces, weak forces of attraction arise between the polymer molecules and the molecules of the lubricant (the reason for the rigidity of PVC is the polarity of the chlorine and hydrogen atoms).

Thanks to the lubrication, the possibility of overheating of the material due to friction is reduced and a more even distribution of heat in the polyvinyl chloride mass is ensured, and the PVC viscosity is reduced. Lubricants, depending on the combination with polyvinyl chloride, can be external and internal. Internal lubricants have sufficient polarity and will work well with PVC. In addition, they reduce the melt viscosity of PVC. Examples of such lubricants: fatty acid esters, stearic acid, ozokerite. Dosage used: 1-3%. External greases have insufficient polarity and therefore do not mix well with PVC. They come out and reduce friction between the polymer melt and the metal surfaces of the processing equipment and forming tool. Used in doses: 0.1-0.4%.

An example of external lubricants: polyethylene waxes.

Problems in the production of PVC compounds

PVC plastics are widely used in the footwear industry. They are used to make shoes for the spring-summer range, for example, the soles of casual shoes, walking shoes and clogs, beach shoes, inexpensive sports shoes, house slippers, soles and tops of rubber boots for various purposes. There are other uses for PVC in the footwear industry.

In accordance with the needs of such a "motley" market, plastic compounds of various purposes and quality are produced. Currently, the market for PVC compounds is quite saturated. In addition to enterprises equipped with specialized compounding equipment, small handicraft firms arose, equipped with unsuitable equipment. In addition to Russian firms, foreign manufacturers have also appeared on the market recently, which leads to a further increase in competition. Usually, high competition leads to higher quality products and lower prices. Unfortunately, competition in the Russian PVC-compound market and the resulting price reduction is often accompanied by a decrease in product quality. Manufacturers of both plastic compounds and footwear reduce the quality, first of all, in the least critical sectors of inexpensive footwear "with a short life cycle" - slippers, summer footwear, etc. Ultimately, the consumer who buys footwear of inadequate quality loses. However, in the conditions of limited payment capacity of most consumers of PVC footwear, the production of low-quality plastic compounds will (unfortunately) continue.

Method for determination of tensile strength at break Method for determination of viscosity by a rotary viscometer for determination of shear rate Method for determination of viscosity with a rotary viscometer for determination of shear rate Determination of the degree of whiteness of surfaces Results and their discussion Influence of the technological mode of obtaining PVC plasticates on their technical parameters Influence of the technological mode of obtaining plasticates on the melt flow rate Modeling the gelation conditions of plastisols Safety and environmental friendliness ...

Share your work on social media

If this work did not suit you at the bottom of the page there is a list of similar works. You can also use the search button

Other similar works that may interest you. Wshm>
21075.		STUDY OF THE OPTICAL PROPERTIES OF MATRICES BASED ON LITHIUM NEOBATE FOR CRYSTAL FIBERS	4.74 MB
	The aim of this work is to refine the threshold concentrations of an anti-photorefractive magnesium impurity by optical spectroscopy methods for the process of changing the dominant types of chromium optical centers in near-stoichiometric lithium niobate crystals, as well as to determine the transparency boundaries of gradient-activated LiNbO3 crystals.
14466.		SYNTHESIS OF METAL COMPOSITES BASED ON PLATINUM, MF-4SK AND POLYANILINE AND STUDY OF THEIR TRANSPORTATION PROPERTIES	1.01 MB
	Conductive properties of polyaniline. Application of composites based on perfluorinated membranes and polyaniline in fuel energy. Objects and research methods. Modification of membranes with polyaniline. Modification of membranes with platinum dispersion using sulfate as a reducing agent ...
12276.		Investigation of the properties of concrete with an expanding additive based on alunite for objects of reconstruction of urban development	97.05 KB
	Domestic and overseas experience and the prospects for the use of stress concretes. Rational areas of application of concretes on alunite expanding cement and the technical and economic efficiency of their use in construction CHAPTER IV. APPLICATION OF ALUNITE-CONTAINING TENSIONING CEMENT AT THE OBJECTS OF RECONSTRUCTION OF URBAN BUILDINGS. Assessment of the operational reliability and suitability for operation of the surveyed building.
16784.		MODIFICATION OF THE MONETARY DYNAMIC MODEL OF D. TOBIN AND ANALYSIS OF THE RUSSIAN ECONOMY	8.91 KB
	Tobin views the government's monetary and financial policy as offering a certain set of assets to the private sector and managing their profitability, and the private sector's response as a change in the structure of demand for assets associated with a change in the asset return vector of the interest rate vector. According to Tobin, the goal of the government's monetary and financial policy is such a change in the structure of the supply of assets by the government and, as a consequence, a change in the vector of profitability that would ensure the maintenance of the rate of accumulation ...
6333.		Cost management based on cost and cost classification	65.77 KB
	Costs as resources consumed reflect the impact on profit on the ability to be a competitive and sustainable enterprise. If for accounting and tax accounting there are legally established differences between the terms costs and costs, then in management accounting all the above names of costs are synonymous. In accounting, the economic categories of costs, costs, costs and cost express the monetary value of the production costs of the enterprise, but at the same time, in terms of the degree of information coverage, it is much ...
4625.		IMPROVEMENT OF LOW TEMPERATURE FUEL PROPERTIES	28.22 KB
	Gasoline and kerosene fractions of oils and products of their processing, as a rule, have low pour points. Diesel and heavier fractions contain many high-melting paraffinic hydrocarbons, and improving the low-temperature properties of these fractions is one of the most important tasks of the oil refining industry.
4986.		The relationship between school anxiety and the properties of temperament	301.01 KB
	The problem of anxiety as a relatively stable personal education relatively rarely arises in its pure form before psychologists. Nevertheless, many authors point out that this problem is relevant at the present time. A large number of works are devoted to this problem, and not only in psychology, but in physiology, biochemistry, psychiatry, sociology, philosophy.
20927.		Determination of the properties of cartographic projections by their equations	41.99 KB
	Purpose of the work: assimilation of the provisions of the general theory of cartographic projections, which are fundamental in the study of the section Mathematical cartography. Initial data: Cartographic projection is given by the equations: According to the given equations of cartographic projection, determine: - orthogonality of the cartographic grid; - partial scales of lengths m n b scale of areas p maximum distortion of angles ω; - a group of projections by the nature of distortions to which a given projection belongs - a type of cartographic grid. Functions ...
9127.		METHODS FOR DETERMINING THE PROPERTIES OF ROCKS	299.19 KB
	Taking into account the previously stated concepts of the hierarchical block structure rocks and arrays and two fundamentally possible ways of determining the various characteristics of the integral and differential, let us consider in more detail the principles of determining individual properties. Thus, to determine the integral density characteristics of the massif represented by various petrographic varieties of rocks and various types of structural inhomogeneities, in principle, it is enough to determine these ...
6627.		Characteristics of the damaging properties of weapons of mass destruction	36.06 KB
	Potent poisonous substances SDYAV formed as a result of the destruction of accidents at chemical industry enterprises All strong toxic substances formed as a result of accidents and destruction at chemical industry enterprises are divided into solid poisons lead arsenic some types of paints and liquid and gaseous poisons carbon monoxide benzene hydrogen sulfide acetylene alcohols ether ammonia, etc. By the nature of toxicity, SDYAV can be subdivided into: substances acting on the generation and transmission of a nerve impulse ...

Edward J. Wixon, Richard F. Grossman
Ed. F. Grossman. 2nd edition
Per. from English ed. V.V. Guzeeva
Publisher: "Scientific Foundations and Technologies"

The book presents all the stages of the development of the formulation of the mixture, describes all the main ingredients of the composition and common additives to them.

In the second edition, some approaches to the mechanism for obtaining PVC-composition were revised, new achievements in this area were described, all the comments of the expert community were taken into account.

The book examines in detail all aspects of creating a mixture, shows how to modify the base for specific requirements for the finished product, explains why and what ingredients give a certain effect in the composition.

Chapter 1. Development of PVC-based compositions

1.1. Introduction

Polyvinyl chloride (PVC, “vinyl” is a commonly used name in trade and manufacturing) has become an important material in the industrial production of flexible products after the Second World War, replacing rubber, leather and cellulose materials in many areas. With the development of processing technology, unplasticized (rigid) PVC began to actively displace metal, glass and wood. The recognition of PVC is based on its favorable price-performance ratio. With proper development of the composition, a wide range of useful properties can be obtained at low cost - weather resistance, inertness to many media, inherent resistance to flame and microorganisms.

PVC is a thermoplastic whose properties are highly dependent on the composition of the composition. The filler content ranges from a few parts per 100 parts of polymer, such as in a standpipe, while in calendered floor tiles, up to hundreds of parts per 100 parts of PVC. The latter is naturally considered to be more of a filler than of PVC.

Soft compositions typically contain up to 70 parts plasticizer per 100 parts polymer. PVC compositions always contain heat stabilizers and lubricants (or ingredients that combine both properties). They may contain fillers, plasticizers, colorants, antioxidants, biocides, flame retardants, antistatic agents, impact and process modifiers, and other ingredients including other polymers. Thus, developing compositions is not an easy process. The purpose of this book is to make it easier to understand and implement.

1.2. Influence of composition on processing

The goal of the formulator is to provide a material that, when processed satisfactorily, has acceptable near-expected properties. All this must be done within certain price parameters. Therefore, in practice, the goal is to develop the best formulation in terms of cost and specific properties. Such development should be considered rational. An alternative to this could be to develop the cheapest material that can hardly be recycled, or barely satisfies the customer's requirements and operating conditions. This alternative usually creates more problems than solves them. Although this book is addressed primarily to the developer of rational compositions, it is hoped that even those on a budget will be able to find a lot of useful things for themselves.

It should be borne in mind that the composition that is optimal this year may not be the same next year. Even if it is optimal in one enterprise, on the same production line, it may not be so optimal in another. Suitability of PVC for different ways processing is largely determined by the knowledge and experience of the process engineer. Compositions based on PVC are processed by calendering, extrusion, injection molding, and can be applied as coatings. Recycling always starts with a mixing stage where additives and PVC are blended. The result is a dry (or not very dry) mixture, plastisol, organosol, mixed latex or solution. The mixing stage is followed by kneading and fusion at the stage of product manufacturing (usually in the case of rigid PVC) or in a separate granulation stage prior to the production of the final product. The pelleting step is a common process for plasticized (flexible) PVC, especially if the pellet is to be transported to another location, for example, to the customer's facility. The dry mixing speed can affect the final productivity.

Although the mixing rate can be influenced by different ingredients, it primarily depends on the type of PVC and the particular plasticizer. Certain types of PVC are specially formulated to absorb the plasticizer quickly. The type of plasticizer (its polarity), viscosity and dissolving power are key factors. However, they are generally selected from the point of view of achieving the desired properties of the composition, and not because of ease of absorption. Sometimes, in order to select the required composition, such actions as preheating the plasticizer or a certain order of adding ingredients are used. Dry mixing and mixing of PVC solutions, latexes, plastisols and organosols are discussed in the corresponding chapters of this book.

The mode of processing through the melt of hard and soft compositions mainly depends on the type of PVC. Examples of low melting resins are low molecular weight homopolymers (low Kf) and vinyl acetate copolymers. Highly solvating plasticizers such as butyl benzyl phthalate (BBP) increase the plasticization rate. It should be emphasized that the choice of both PVC type and plasticizer is dictated by the application of the material, while other ingredients such as lubricants, stabilizers and process modifiers are selected to increase processing speed. In large-scale production of compositions based on hard Composition development 7

PVC is used directly for the production of products such as pipes, siding and window profiles. Certain flexible PVC applications, such as extrusion of wire insulation, are also often dry mix based. However, the most plasticized compositions are produced by melt blending in a closed mixer followed by granulation in an extruder or by using a combination of two extruders combining the functions of a mixer and a granulator. In melt processing, viscosity and frictional force against metal surfaces are not only obvious factors required for melting and pelletizing, but they also limit productivity, cause equipment wear, and are possible sources of PVC degradation. This, of course, applies to processing in the manufacture of not only granules, but also specific products. All of the above largely depends on the recipe and the choice of equipment. There are two extreme scenarios for organizing the production of compositions:

1. An optimal composition with the best price-quality ratio is being developed. Then the processing equipment is installed to achieve the highest productivity and the best quality. When expanding production, the same equipment is installed. This action plan is applied in the case of large-scale production of rigid PVC composites and underlies the rapid growth of this sector in North America... As a result, the development of new and improved products encourages cooperation between suppliers of equipment and ingredients.

2. Formulation development continues, often endlessly, to create a composition that meets the requirements after processing to the edge of the capabilities of the equipment that is at hand or purchased for a minimal price. This is a typical case in the production of some soft compositions. This approach is the main reason why some market participants cannot withstand competition with foreign manufacturers and the reason for replacing plasticized PVC with newer materials, for example, thermoplastic elastomers.

1.3. Influence of composition on properties

In unplasticized compositions, stiffness (flexural strength) increases with increasing molecular weight (MW). Up to some concentration of filler, the addition increases flexural strength, while increases in impact modifiers and processability tend to reduce strength until they begin to work as warp temperature increasing additives.

On the other hand, the tensile strength tends to go beyond the limit with increasing MM, although the modulus at low deformations runs parallel to the flexural strength. Abrasion and creep strength increases with increasing MM, which is typical for plastics. The addition of a filler can enhance both properties as long as the particle size and shape is conducive to creating a spatial structure in the material.

Chemical resistance, oil resistance, thermal warpage resistance increase, while productivity and ease of processing decrease with increasing MM. Accordingly, when developing compositions based on a high molecular weight polymer, additives are used that increase the fluidity, as well as additives that compensate for the disadvantages of a low molecular weight polymer. In other words, the main purpose of supplements is to correct problems caused by other supplements.

Compositions containing about 25 parts of a "good" plasticizer per 100 parts of PVC, such as di (2-ethyl) hexyl phthalate, are considered semi-rigid (100% tensile modulus of about 23 MPa). The modulus at low elongation is an acceptable characteristic of the flexibility of plasticized PVC. It increases slightly with increasing molecular weight and decreases strongly with increasing plasticizer content. So when the content of 35 parts of DOP (or plasticizer with comparable activity) per 100 parts of PVC, the material is considered flexible. At 50 parts of DOP, the tensile modulus drops to about 12 MPa, and at 85 parts of DOP per 100 PVC - to about 4 MPa, which indicates the extreme flexibility of the material. Less effective plasticizers need to be used at higher concentrations. In plasticized compositions, tensile strength increases more or less linearly with increasing molecular weight of the polymer. The dependence of strength on the type of plasticizer and its content is stronger. Tensile strength and elongation often, but not always, decrease with increasing filler content. Tear strength improves with increasing MM, as does abrasion resistance, but these properties are influenced by additives. Copolymerization with vinyl acetate has the same effects as adding a plasticizer, but usually at a higher cost.

The main factors affecting brittleness and flexibility at low temperatures are the type of plasticizer and its content. Compositions designed for low temperatures often contain a mixture of plasticizers, one of which is, for example, di (2-ethyl) hexyl adipate (DOA). Plasticization usually reduces chemical resistance, solvent resistance and oil resistance. This can be contrasted with the use of polymer plasticizers, which is accompanied by a natural increase in cost and complication of processing, or through the use of mixtures and alloys with oil-resistant polymers, for example, with nitrile butadiene rubber (NBR).

One of the most important uses of plasticized PVC is in wire insulation. The choice of plasticizer depends on the service conditions of the product. The plasticizer should have low volatility during heat aging. Loss of plasticizer is the main reason for the decrease in elongation after heat aging. For use in dry conditions, a filler calcium carbonate (CaCO3) is added to the composition. The content varies with the balance between the price of the material and its properties. Insulation materials for use in humid environments (eg North America) must have a stable volume resistivity for 6 months in water at 75 or 90 ° C. Such materials instead of calcium carbonate contain electrical grades of calcined (calcined) kaolin. For this application of the insulating material, the plasticizer and other components must also be of electrical quality.

In terms of fire resistance, plasticized PVC compositions vary from slow burning, when flammable plasticizers are used, to self-extinguishing ones containing: antimony oxide, whose action is synergistically enhanced by halogen, flame retardant plasticizers, and water-based fillers such as aluminum trihydrate or magnesium hydroxide. Although water-based fillers increase thermal stability, when using fire-resistant plasticizers, it is necessary to increase the content of stabilizers. Water-based fillers also reduce smoke generation by promoting oxidation of hot soot particles. It is believed that this reaction proceeds via metallocarbonyl intermediates and is catalyzed by metal compounds that form carbonyls. The most commonly used molybdenum is in the form of ammonium octamolybdate (OMA), which reacts at the right temperatures.

Fire resistance increases, and smoke generation is reduced with the help of fillers that promote the formation of heat-conducting caked coke particles during combustion. This refers to aqueous fillers and certain zinc compounds, especially zinc borate and tin hydroxide. The use of zinc compounds usually requires higher concentrations of stabilizers. This is not the case with tin oxide, but its use increases smoke production. Therefore, the development of a highly flame retardant flexible material based on PVC requires a complex selection of ingredients. The overall balance of physical and fire-resistant properties of PVC-based plasticized material is much better than that of polyolefin analogs that do not contain halogen. These analogs are usually so overloaded with aqueous fillers that the polymer is nothing more than a binder.

Rigid PVC foams, consisting of two outer hard layers and a foamed inner layer, have become ubiquitous in pipes, siding and plastic boards. In addition to reducing weight and cost, the thermal conductivity of vinyl siding is reduced, and plastic boards are easier to nail and saw. Foamed soft PVC products are most often obtained from plastisols, for example, for vinyl linoleum. In this case, foaming of the plastisol can be achieved mechanically, introducing air into the paste by means of vigorous stirring, and chemically using foaming agents (foaming agents), most often azodicarbonamide. The latter is easily activated by some additives, which are often components of a heat stabilizer, known in such cases under the name “kickers”. Surfactants are used to improve the quality of the cellular structure, which also depends on the choice of polymer and plasticizer.

Light and weather resistance is achieved in several ways. The outer layer (top coat) of a vinyl siding or window profile must contain a sufficient amount of high quality titanium dioxide (TiO2). Its high dielectric constant allows absorption of a quantum of light and dissipation of energy in the form of heat, after which a quantum of low energy is emitted. This limits the volume in which incident light is able to initiate a chain reaction of free radical oxidation. The corresponding type of carbon black has the same effect and is widely used in cable jackets and agricultural coatings. Of course, it is useful to have materials not only in white, but, for example, black or gray. TiO2 and various pigments are used to paint vinyl siding.

Another way to obtain colored siding is by applying lightfast coatings such as acrylic or polyvinyl difluoride (PVDF) to the PVC surface. Acrylic coatings are also used with PVC plastisols containing polyesters to improve printability, reduce plasticizer migration and improve light fastness. Organic ultraviolet light (UV) absorbers are added to produce brightly colored products. Soot and TiO2 behave similarly. A quantum of light is absorbed, transforming the UV absorber into an excited state. The energy dissipates rather slowly in the form of heat, which does not harm the material. Light absorbers such as hydroxybenzophenones and benzotriazoles are not antioxidants; in fact, they themselves require protection against oxidation.

A relatively new class of materials, hindered amine light stabilizers (HALS) *, are not only antioxidants, but are involved in chain reactions of antioxidants. Their use in PVC is currently under investigation. The weather resistance of PVC-based compositions has been studied on a variety of devices that simulate sunlight. There is only a relative correlation between these methods and actual weather tests. The influence of natural exposure is different for different areas. Accelerated light aging is believed to result in a wide range of results. However, these methods are useful for comparing one formulation to another and it is often assumed that the results are predictable relative to field trials. In addition, plasticized compositions are exposed to microbial attack in wet field conditions. Since it is often impossible to predict the operating conditions, biocides are usually incorporated into plasticized compositions.

In real conditions, mixing of macroparticles and low-molecular-weight ingredients, contrary to the entropy factor, does not occur homogeneous mixing of the components. In turbulent flow, stratification is often preferable to homogenization. Deviation from laminar flow during processing can cause partial separation of the composition, which leads to the release of ingredients on the surface of the equipment and their accumulation on the screen of the extruder The degree of separation of the mixture (phase instability) is a function of the density of the component. Therefore, the first ingredient found on the sieve is lead * HALS - hindered amine light stabilizers.

stabilizer or its reaction product, titanium dioxide, zinc or barium stabilizers. It should be emphasized that turbulence, in addition to a negative effect (separation of the composition), also leads to a positive effect - the destruction of agglomerates (dispersion of the filler). However, turbulence must be minimized in order to achieve the best product quality in the production process.

An important consideration that must be taken into account by the formulator is whether the components will remain unchanged over the life of the product. For example, surface oxidation of a siding or profile can cause hardening due to cross-linking. As a result of the increased surface modulus of elasticity for this reason, the compatibility of the ingredients decreases, leading to the release of a white bloom on the surface of the article, which consists of the most dense components, for example, TiO2. The release on the surface of the plasticizer from the plasticized PVC can be highly undesirable if it comes into contact with another polymer, for example polystyrene, which will dissolve or swell in the plasticizer.

Migration of the plasticizer to the surface will also be undesirable if the surface of the product comes into contact with the pressure-sensitive adhesive. Migration can be minimized by formulating with polymeric plasticizers, as in refrigerator seals, or by using formulations with BNK or an ethylene vinyl acetate (EVA) copolymer alloy. The plasticizer can also bring to the surface and other components of the formulation, which can add their own odor to the odor from the packaging film or refrigerator parts. Sometimes the migration of plasticizer to the surface is useful, as is the case with self-cleaning floor coverings, for which the plasticizer is selected to have a low tendency to migrate to the surface, limiting penetration and facilitating the removal of oily contaminants.

Plasticizer migration is also a concern in the use of plasticized PVC film for pharmaceutical and food packaging. Despite the migration of DOP in medical devices and DOP and DOA in product packaging, they are widely used because their long history of safe use, low price and high certification costs have worked against proposals for more suitable plasticizers.

Here are some of the most common questions that are faced when proposing a new or improved ingredient:

Will its use be economically justified?

Can long term performance be guaranteed?

Can you be sure of getting a certificate?

The latter is a reminder that effective formulation cannot be done from a vacuum. There should be cooperation and exchange of information between all departments of the proposed supplier of the new additive.

The above simplified generalizations will be explored in detail in the following chapters.

1.4. Composition development procedure

If the intended use is new, then, keeping in mind that a patent might be obtained, it is necessary to ensure that recorded records relating to the development of the composition and to the trials are kept. If similar products exist in a given area, then their advantages and limitations must be considered. It is necessary to make a list of characteristics that would be ideal (sometimes they may not be achievable) and consider with the help of marketers what considerations would help promote the product. Next, you should consider the relationship between the conceived project and others in the work, and work on those in which there is confidence. Analysis before taking action can be very helpful. It is often enough to make an educated guess about a promising solution before experimenting. These stages, although difficult to formalize, are part of the design of the experiments.

The analysis should be continued with a review of the technical specifications (TS) of the product, which include not only documents from the authorities state regulation but also excerpts from customer requirements or samples of competitive proposals. It should be ensured that the test methods are appropriately specified. In some individual cases, the original recipe may be obtained from the sources of the supplier (or specialist literature such as this book). Component suppliers are often eager to collaborate on a test program. On the other hand, there are applications for which the developer only gives a minimum of formulation development information. However, with the help of modern analytical instruments and sufficient effort, the composition of all compositions can be recreated.

From this point of view, any program of experiments can be planned both intuitively (which is usually in the case of a well-known general field of application) and statistically (which is common in innovative development). In the most common case, the ongoing experimental work is probably performed by a laboratory assistant, while the researcher is not involved in technical tasks. Instructions to the laboratory technician should indicate the most likely experimental results so that unexpected results can be perceived and reported immediately. We learn from the unexpected. The successful researcher follows Pasteur's aphorism that luck smiles upon those who are ready for it. Of course, it is better to do the experiments yourself (unless the technician is expected to do the job more thoroughly).

As far as possible, it is necessary to record the mixing conditions, note the characteristics of the temperature change over time at the stages of mixing and kneading. This can be verified by testing the same composition in a rheometer. If it is important to compare the physical properties before and after heat aging, then it must be ensured that the test pieces were made with the composition fully melted. When studying deformation properties, especially in comparison with control or competitive samples, it is better to construct a complete stress versus strain curve than to obtain only the values of the yield strength and ultimate strength. An experienced chemist can infer formulation differences from the shape of such curves. If the sample shows significant deviations from the arithmetic mean, then it is useful to try to establish the cause. For example, an unusually low tensile modulus in combination with a more or less normal 100 percent modulus is a signal to suspect that a given sample has fractured due to inclusions of insufficiently dispersed ingredients. (An unusually high tensile strength will certainly be more tempting.)

Finally, you should check the results for each program of experiments to determine if they will contradict or, conversely, correspond to some other problem of interest - perhaps you should not have rejected a simple solution in the past.

1.5. Ingredient cost

While some blend components are sold by volume, most are purchased by weight because they are premixed products. On the other hand, PVC products are often sold by volume. Therefore, it is necessary to know the prices for a standard volume of materials (almost everywhere in the world it is a liter). To obtain the volumes of ingredients, you need to divide their weight in kilograms by their density. The ratio of total weight to total volume gives the calculated density of the composition. It is common in the United States to express the weight of ingredients in a formulation in pounds. The "associated" volume is lb / volume. Most often it is calculated by dividing the weight by the specific gravity, that is, the ratio of its density to the density of pure water at a given temperature. Thus, the specific gravity (HC) is a dimensionless quantity, and the lb / volume (or kg / volume) is an artificially created quantity.

In unplasticized PVC, the calculated HCs should correspond well to those in the final product. Downward changes indicate a porous structure or incomplete fusion. The specific gravity of plasticized PVC products should be slightly higher than the calculated one, depending on the content of the plasticizer. This is the well-known effect of solvation. If there is no such effect, that is, with a solid content of the plasticizer, there is a complete (with an accuracy of 0.001) correspondence between the observed HC and the calculated one, then (after repeating the calculations) it is necessary to carefully check the tendency of the plasticizer to migrate. In general, the specific gravity should be checked regularly to assess the correct formulation of the composition, before spending time on practical testing. 14

The conclusion is to periodically check the mass balance, that is, to check if the amount of polymer and other components matches the amount of the composite material obtained.

Loss of plasticizer during processing can occur by evaporation, especially during fusion of the plastisol coating. In this case, losses can be at the level of several percent. This can be inescapable and inherent in the product and must be factored in in cost calculations and contamination control. environment.

Specific weights common ingredients are presented in the section below to facilitate cost calculations.

Table 1.1. Specific gravity of polymer components PVC homopolymer 1.40
PVC / vinyl acetate (VA), 2% VA 1.39
PVC / VA, 5% VA 1.38
PVC / VA, 10% VA 1.37
PVC / VA, 15% VA 1.35
Acrylic impact modifier 1.10
Acrylic additive to improve processability 1.18
Acrylonitrile butadiene styrene (ABS) impact modifier 0.95-1.04
Styrene butadiene methacrylate (MBS) impact modifier 1.0
Poly (α-methylstyrene) 1.07
Chlorinated polyethylene (CPE), 42% chlorine 1.23
Chlorosulfonated polyethylene 1.18
Nitrile butadiene rubber (NBR) 0.99
PVC / polyurethane (PU) blends 1.3-1.4

1.6. Specific gravity of ingredients

HC polymer ingredients are presented in table. 1.1. HC phthalate plasticizers are given in table. 1.2., Special plasticizers - in table. 1.3, and "different" plasticizers - in table. 1.4. HCs of commonly used organic additives are given in table. 1.5, and inorganic additives - in table. 1.6.

Table 1.2. Specific gravity of phthalate plasticizers Dibutyl phthalate (DBP) 1.049
Diisobutyl phthalate (DIBP) 1.042
Butyl octyl phthalate (BOP) -1.0
15 Dihexyl phthalate (DHF) 1.007
Butylbenzyl phthalate (BBP) 1.121
Dicyclohexyl phthalate (DCHF) 1.23
Di (2-ethyl) hexyl phthalate (DOP) 0.986
Diisooctyl phthalate (DIOP) 0.985
Dicaprilphthalate (DKF) 0.973
Diisononyl phthalate (DINP) 0.972
Di-trimethylhexylphthalate 0.971
C9 linear phthalate 0.969
Diisodecyl phthalate (DIDP) 0.968
C7-C9 linear phthalate 0.973
n-C6-C10 (610P) phthalate 0.976
n-C8-C10 (810P) phthalate 0.971
C11 linear di-n-undecyl phthalate (DUV) 0.954
Undecyl dodecyl phthalate (UDP) 0.959
Ditridecyl phthalate (DTDF) 0.953

Table 1.3. Specific weights of special plasticizers

Di (2-ethyl) hexyl adipate (DOA) 0.927
Diisooctyl adipate (DIOA) 0.928
Diisodecyl adipate (DIDA) 0.918
n-C6-C10 adipate (610A) 0.922
n-C8-C10 adipate (810A) 0.919
Di-n-hexyl azelainate (DNGZ) 0.927
Di (2-ethyl) hexyl azelaate (DOZ) 0.918
Diisooctyl azelainate (DIOS) 0.917
Dibutyl sebacate (DBS) 0.936
Di- (2-ethyl) -hexyl sebacate (DOS) 0.915
Diisooctyl sebacate (DIOS) 0.915
Tri (2-ethyl) hexyl trimellitate (TOTM) 0.991
Thiriisooctyl trimellitate (THIOTM) 0.991
n-C8-C10 trimellitate 0.978
Triisononyl trimellitate (TINTM) 0.977
(2-ethyl) hexyl epoxytallate 0.922
Epoxidized soybean oil 0.996
Epoxidized Linseed Oil 1.034
Table 1.4. Specific weights of various plasticizers

Tricresil phosphate (TCP) 1.168
Tri (2-ethyl) hexyl phosphate 0.936
Ethylhexyldiphenyl phosphate 1.093
Isodecyldiphenyl phosphate 1.072
Isopropyl diphenyl phosphate 1.16-1.18
Acetyltributyl citrate 1.05
Chlorinated paraffin, 42% chlorine 1.16
Di (2-ethyl) hexyl isophthalate (DOIF) 0.984
Di (2-ethyl) hexyl terephthalate (DOTP) 0.984
Dipropylene glycol dibenzoate 1.133
Isodecyl benzoate 0.95
Propylene glycol dibenzoate 1.15
Herkoflex® 707 1.02
Nuoplaz® 1046 1.02
Trimethyl pentanediol isobutyrate 0.945
Low molecular weight polyester 1.01-1.09
Medium molecular weight polyester 1.04-1.11
High molecular weight polyester 1.06-1.15
Naphthenic oil 0.86-0.89
Alkyl phenyl sulfonate 1.06
Table 1.5. Specific gravity of organic additives Ethylene bis (stearamide) 0.97
Calcium stearate 1.03
Glyceryl monostearate 0.97
Paraffin wax 0.92
Low molecular weight polyethylene wax 0.92
Oxidized polyethylene wax 0.96
Mineral oil 0.87
Stearic acid 0.88
Bisphenol A 1.20
Topanol® KA 1.01
Irganox® 1010 1.15
Irganox® 1076 1.02
Benzophenone UV-absorbers 1.1-1.4
Benzotriazole UV absorbers 1.2-1.4
Hindered Amine Light Stabilizers (HALS) 1.0-1.2

Table 1.6. Specific gravity of inorganic additives Calcium carbonate 2.71
Talc 2.79
Calcined kaolin 2.68
Barytes 4.47
Mica 2.75
Aluminum trihydrate 2.42
Antimony trioxide 5.5
Antimony pentoxide 3.8
17 Magnesium hydroxide 2.4
Basic magnesium carbonate 2.5
Molybdenum oxide 4.7
Zinc borate 2.6
Soot 1.8
Titanium dioxide 3.7-4.2

1.7. Experiment planning

Experimentation has two main goals: to improve the understanding of the results obtained, which gives an idea of the mechanism; and develop or improve specific products or processes. The goals are inseparable, despite attempts to separate them. Understanding the chemical and physical phenomena that underlie a problem is as accurate as the results of experiments create and modify theoretical explanations. It is important that the designer of PVC composites reads this book before moving on to Chapter 22, which explains how to mechanize problem solving.

Literature

1. E.A. Coleman, Introduction to Plastics Additives, in Polymer Modifiers and Additives, J.T. Lutz, Jr, and R. F. Grossman, eds., Marcel-Dekker, New York, 2001. 2. M. L. Dennis, J. Appl. Phys., 21, 505 (1950).

It might be helpful to read: