The Formulation of Plastics

Reinforcement, e.g., glass fibre Increased strength and stiffness 

Light stabilisers Increased resistance to degradation from daylight 

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Thermoplastic hydrocarbon resins and residue resins for the formulation of plastics, adhesives and binding agents,... 

Chapter 1 has been updated to provide background to polymer chemistry and plastic formulations. It is an introductory chapter that summarizes the chemistry of making polymers, the formulation of plastics, testing and test methods, and plastic selection. 

However, thermal reprocessing of post-consumer waste plastics introduces changes into the materials that mean they may be unusable for the applications for which they were originally intended, even if the same synthetic polymer type is reprocessed. These changes are partly due to the differences in the formulation of plastics in different applications, and partly due to chemical and physical changes that occur during the thermal reprocessing of the material. 

Gas-Liquid Chromatography.—Phthalic esters - which are extensively used as plasticizers in the formulation of plastics used to make containers for solvents, etc. - have been found as contaminants during the analysis of polysaccharides by gas chromatography of the alditol acetate derivatives for example, dibutyl phthalate behaves as a tetritol tetra-acetate on g.l.c. and di(2-ethylhexyl) phthalate has a retention time close to that for xylitol penta-acetate. The contamination by phthalic esters can be minimized by distilling all solvents used in the analytical steps or by using smaller volumes of potentially contaminated solvents. 

Oldroyd, J. G., 1947. A rational formulation of the equations of plastic flow for a Bingham solid. Proc. Camb. Philos. Soc. 43, 100-105. 

Cellular Ebonite. CeUular ebonite is the oldest rigid ceUular plastic. It was produced in the early 1920s by a process similar to the processes described for making ceUular mbber. The formulation of mbber and vulcani2ing agent is changed to produce an ebonite rather than mbber matrix (114). 

Flame and Smoke Retardants. Molybdenum compounds are used extensively as flame retardants (qv) (93,94) in the formulation of halogenated polymers such as PVC, polyolefins, and other plastics elastomers and fabrics. An incentive for the use of molybdenum oxide and other molybdenum smoke and flame retardants is the elimination of the use of arsenic trioxide. Although hydrated inorganics are often used as flame retardants, and thought to work by releasing water of crystallization, anhydrous molybdenum oxides are effective. Presumably the molybdenum oxides rapidly form... 

Plasticizer Efficiency. This is a measure of the concentration of plasticizer required to impart a specified softness to PVC. Such a softness of material may be measured as a British Standard Softness (BSS) or a Shore hardness (Pig. 1). Por a given acid constituent of plasticizer ester, ie, phthalate, adipate, etc, plasticizer efficiency decreases as the carbon number of the alcohol chain increases, eg, for phthalate esters efficiency decreases in the order DBP > DIHP > DOP > DINP > DIDP > DTDP. An additional six parts per hundred in PVC of DIDP rather than DOP is required to give a hardness of Shore 80 when ah. other formulation ingredients remain constant. The consequence of this depends on the overall formulation and product costs. In addition to size of the carbon number of the alcohol chain, the amount of branching is also significant the more linear isomers are of greater efficiency. 

The future for amino resins and plastics seems secure because they can provide quaHties that are not easily obtained in other ways. New developments will probably be in the areas of more highly specialized materials for treating textiles, paper, etc, and for use with other resins in the formulation of surface coatings, where a small amount of an amino resin can significantly increase the value of a more basic material. Additionally, since amino resins contain a large proportion of nitrogen, a widely abundant element, they may be in a better position to compete with other plastics as raw materials based on carbon compounds become more costly. 

Large and small shapes may be sUp cast from both plastic and nonplastic mixes by the usual techniques. Precise shapes, such as glass feeder parts, are made in this way as well as large flux blocks. The process requkes the formulation of a sUp of suitably stable character to be poured into a plaster mold to be dewatered. After it solidifies, the mold is removed and dried further before firing. 

Castor Wax. Castor wax [8001-78-3] is catalyticahy hydrogenated castor bean oil. The wax has a melting point of 86°C, acid number of 2, saponification number of 179, and an iodine number of 4. Castor wax is used primarily in the formulation of cosmetics. Derivatives of castor wax are used as surfactants and plastics additives. 

The largest traditional use for montan waxes was as a component in one-time hot-melt carbon-paper inks. With the decrease in the use of carbon-paper inks, uses for the refined grades have become predominant, mainly in the formulation of poHshes and as plastics lubricants. The alcohol ester derivatives may be used as components of articles intended for use with foods as regulated by the FDA in 21 CFR 178.3770. 

Almost all PVC powder coatings are appHed by the fluidized-bed coating process. Although some electrostatic spray-grade formulations are available, they are very erratic in their appHcation characteristics. The resistivity of plasticized PVC powders is low compared to other powder coating materials and the appHed powder quickly loses its electrostatic charge. For the same reason, PVC powders show poor appHcation characteristics in an electrostatic fluidized bed and are seldom used in this process. 

Syndiotactic Polybutadiene. Syndiotactic polybutadiene is a unique material that combines the properties of plastic and mbber. It melts at high (150—220°C) temperatures, depending on the degree of crystallinity in the sample, and it can be molded into thin films that are flexible and have high elongation. The unique feature of this plastic-like material is that it can be blended with natural mbber. 1,4-Polybutadiene and the resulting blends exhibit a compatible formulation that combines the properties of plastic and mbber. 

The Epoyj Resin Formulators Training Manual, The Society of Plastics Industry, Inc., New York, 1984. 

There are, however, certain materials used as ingredients in the manufacture of plastics, which almost invariably give a corrosive product. Included in this category are wood, which is frequently used as a filler or as part of a composite drying oils, used in paints, adhesives, jointing compounds and linoleum and esters of volatile acids frequently retained in certain cold setting formulations, especially some paints. ... 

As these problems were encountered in the past, it became evident that we did not have at hand the physical or mathematical description of the behavior of materials necessary to produce realistic solutions. Thus, during the past half century, there has been considerable effort expended toward the generation of both experimental data on the static and dynamic mechanical response of materials (steel, plastic, etc.) as well as the formulation of realistic constitutive theories (Appendix A PLASTICS DESIGN TOOLBOX). 

As reviewed within each one of the major classes of plastics (PE, PVC, PC, etc.) there are usually a very wide variety of specific formulations, each of which has slightly different properties and/or processing capabilities at various costs. Prices, too, will tend to vary depending upon the supplier, the current state of the market, and the volume of plastic that the processor is prepared to purchase. 

MIL-P-47136 covers one formulation of plasticized PVC used in the production of flexible tubing, cord, film, sheet, and other various extruded shapes. The Specification requirements are concerned with electrical, mechanical and physical properties and shelf life Refs 1) D. Haft, PATR1592 (1946) 2) H.J. 

Alkylphenol ethoxylates (APEs) are nonionic surfactants that are used in the manufacturing of plastics, agricultural chemicals, cosmetics, herbicides, and industrial detergent formulations. Alkylphenols such as nonylphenol (NP) are the products of... 

Preservative availability may be appreciably reduced by interaction with packaging materials. Examples include the permeation of phenolic preservatives into the rubber wads and teats of multi-dose injection or eye-drop containers and by their interaction with flexible nylon tubes for creams. Quaternary ammonium preservative levels in formulations have been significantly reduced by adsorption onto the surfaces of plastic and glass containers. Volatile preservatives such as chloroform are so readily lost by the routine opening and closing of containers that their usefulness is somewhat restricted to preservation of medicines in sealed, impervious containers during storage, with quite short use lives once opened. 

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