Plastics Resins

It is extensively used in the preparation of dyestuffs. Combines with diazonium salts to form oxyazo-colouring matters. Gives rise to fluorescein dyes on fusion with phthalic anhydride. Used for production of plasticizers, resins, adhesives. 

Aqueous solutions of 50% acrylamide should be kept between 15.5 and 38°C with a maximum of 49°C. Below 14.5°C acrylamide crystallizes from solution and separates from the inhibitor. Above 50°C the rate of polymer buildup becomes significant. Suitable materials of constmction for containers include stainless steel (304 and 316) and steel lined with plastic resin (polypropylene, phenoHc, or epoxy). Avoid contact with copper, aluminum, their alloys, or ordinary iron and steel. 

Plastics. In the plastics industry, the term filler refers to particulate materials that are added to plastic resins in relatively large, ie, over 5%, volume loadings. Except in certain specialty or engineering plastics appHcations, plastics compounders tend to formulate with the objective of optimizing properties at minimum cost rather than maximizing properties at optimum cost. Table 2 fists typical plastic fillers and their uses. 

Injection Molding. Matched metal molds are used in the fabrication of plastic closures, specialty packages, and botde preforms. In conventional injection mol ding the plastic resin is melted in an extmder which forces a measured quantity or shot into a precision-machined chilled mold after which the nozzle of the extmder is withdrawn. 

The reinforcing ply acts as the carrier for the plastic resin during intermediate processing steps known as saturation and B-staging. It is this ply that together with the resin makes a laminate a composite material, and the layering of these pHes that makes the final product a laminate. 

The higher temperatures ate used for glass-filled or high viscosity materials and the lower temperatures for low viscosity or plasticized resins. 

Gum Elemi. This resin, tapped from trees in the Philippines, contains a higher concentration of essential oils than other natural resins. It is a soft, sticky, plastic material that can be deformed manually. Gum elemi [9000-75-3] contains 20—25% essential oils, 13—19% acids, 30—35% resenes (condensed decarboxylated resin acids), and 20—25% terpenic resinols (condensed terpene alcohols). It has an acid number of 20—35 and a saponification number of 20—40. Gum elemi is a film-forming plasticizing resin used in lacquers. 

To improve processing and to plasticize the mbber compound, numerous processing agents have been used over the years, eg, petroleum and ester plasticizers, resins and tars, Hquid mbber peptizers, peptizers, fatty acids and derivatives from vegetable oils, and polyethylene and hydrocarbon waxes. 

Ester plasticizers are used mainly in very polar elastomers, such as neoprene and nitrile mbber, to improve low or high temperature performance or impart particular oil or solvent resistance to a compound 5—40 parts are commonly used (see Plasticizers). Resins and tars are added to impart tack, soften the compound, improve flow, and in some cases improve filler wetting out, as is the case with organic resins in mineral-filled SBR. Resinous substances are also used as processing agents for homogenizing elastomer blends. 

Some by-product polyethylene waxes have been recently introduced. The feedstock for these materials are mixtures of low molecular weight polyethylene fractions and solvent, generaHy hexane, produced in making polyethylene plastic resin. The solvent is stripped from the mixture, and the residual material offered as polyethylene wax. The products generaHy have a wider molecular weight distribution than the polyethylene waxes synthesised directly, and are offered to markets able to tolerate that characteristic. Some of the by-product polyethylene waxes are distHled under vacuum to obtain a narrower molecular weight distribution. 

Internal surfactant antistats ate physically mixed with the plastic resin prior to processing. When the resin is melted, the antistat distributes evenly in the polymer matrix. The antistat usually has some degree of solubiUty in the molten polymer. However, when the polymer is processed (extmded, molded, etc) into its final form and allowed to cool, the antistat migrates to the surface of the finished article due to its limited solubiUty in the solidified resin. The molecule of a surface-active agent is composed of a polar hydrophilic portion and a nonpolar hydrophobic portion. The hydrophilic portion of the surfactant at the surface attracts moisture from the atmosphere it is the moisture that has the static dissipative effect. 

Cobalt(II) phosphate octahydrate [10294-50-5], Co2(P0272 8H20, is a red to purple amorphous powder. The product is obtained by reaction of an alkaline phosphate and solutions of cobalt salts. The material is insoluble in water or alkaU, but dissolves in mineral acids. The phosphate is used in glazes, enamels, pigments (qv) and plastic resins, and in certain steel (qv) phosphating operations (see Enamels,PORCELAIN ORVITREOUS). 

Dyes should be checked for migration, sublimation, and heat stabiUty before use. These precautions are particularly important for plasticized resins. 

Processing is similar to other engineering plastic resins. Drying is necessary before extmsion or molding. Special drying precautions are required for PET products to prevent degradation and splay. 

Machinery (except electrical) Manufacture of equipment for construction, elevators, moving stairways, conveyors, industrial trucks, trailers, stackers, machine tools, etc. Slag, sand, cores, metal scrap, wood, plastics, resins, rubber, cloth, paints, solvents, petroleum products... 

Professional scientific controlling instruments Manufacture of engineering, laboratory, and research instruments and associated equipment Metals, plastics, resins, glass, wood, rubber, fibers, abrasives... 

Miscellaneous manufacturing Manufacture of jewelry, silverware, plated ware, toys, amusement, sporting and athletic goods, costume novelties, buttons, brooms, brushes, signs, advertising displays Metals, glass, plastics, resin, leather, rubber, composition, bone, cloth, straw, adhesives, paints, solvents... 

Chemical compounds manufactured at petrochemical plants include methanol, formaldehyde, and halogenated hydrocarbons. Formaldehyde is used in the manufacture of plastic resins, including phenolic, urea, and melamine resins. Halogenated hydrocarbons are used in the manufacture of silicone, solvents, refrigerants, and degreasing agents. 

Plastics are long chain, high molecular weight polymers which can be formed under application of heat and pressure into desired shapes and contours by a variety of processing techniques. Plastic resins are classified either as thermoplastics, if the material can be reprocessed under heat and pressure, or as thermosets if the material, once formed, cannot be reprocessed. 

Harz-alkohol, m. resin alcohol, -austauscher, m. ion-exchange resin, -baum, m. pitch tree (applied to various conifers), -bildung, /. resin (or rosin) formation, (of gasoline) giim-ming. -brei, m. a viscous material trapped in the pores of a synthetic plastic, resin magma, -cerat, n. Pharm.) rosin cerate, -elektrizi-tat, /. resinous (negative) eleetricity. 

To any one concerned with the production of plasticized resins, compatibility has long meant the ability of two or more materials to mix with each other to form a homogeneous composition of useful desired plastic properties [44,45]. A plasticizer, therefore, can be defined as a material that will soften and make inherently rigid and even brittle polymers flexible. Plasticizers are also sometimes... 

Conversations with engineers of plastics resin manufacturers. 

Mechanical recycling uses MPW as a replacement for primary plastic resin. 

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