Polyesters Plastics

Bromine is used in the manufacture of many important organic compounds including 1,2-dibromoethane (ethylene dibromide), added to petrol to prevent lead deposition which occurs by decomposition of the anti-knock —lead tetraethyl bromomethane (methyl bromide), a fumigating agent, and several compounds used to reduce flammability of polyester plastics and epoxide resins. Silver(I) bromide is used extensively in the photographic industry... 

Polyester film Polyester plasticizers Polyester polyol Polyester polyols Polyester resins... 

Polyester plasticizers give the best performance in this area, with performance increasing with molecular weight. Additionally, branched esters have somewhat higher volatUities than their linear equivalents. 

The crystalliza tion resistance of vulcaniza tes can be measured by following hardness or compression set at low temperature over a period of time. The stress in a compression set test accelerates crystallization. Often the curve of compression set with time has an S shape, exhibiting a period of nucleation followed by rapid crystallization (Fig. 3). The mercaptan modified homopolymer, Du Pont Type W, is the fastest crystallizing, a sulfur modified homopolymer, GN, somewhat slower, and a sulfur modified low 2,3-dichlorobutadiene copolymer, GRT, and a mercaptan modified high dichlorobutadiene copolymer, WRT, are the slowest. The test is often mn near the temperature of maximum crystallization rate of —12° C (99). Crystallization is accelerated by polyester plasticizers and delayed with hydrocarbon oil plasticizers. Blending with hydrocarbon diene mbbers may retard crystallization and improve low temperature britdeness (100). 

Acrylates and methacrylates, which are critical to the production of polyesters, plastics, latexes, and synthetic lubricants, can also be produced from these oxygenated intermediates. 

Polyester plastics Group of plastics composed of resins derived principally from polymeric esters that have recurring polyester groups in the main polymer chain. These polyester groups are cross-linked by carbon-carbon bonds. 

The chassis is made from a 1/4 in. sheet of either ABS or TPO vacuum formed into a tub and reinforced with reinforced pultruded glass fiber-TS polyester plastic tubing. The hood and other products are being made from a 20 mm thick sandwich of thermo-formed PPO-alloy skins, glass fabric infused with thermosetting vinyl ester, and a urethane foam core. The bumper and front fascia is thermoformed from a polyolefin elastomer sheet with an UV-resistant cap layer of DuPont s Tediar PVF film. The dash and... 

Figure 8-66 RP (glass fiber-TS polyester plastic) tank trailers are used for hauling corrosive and hazardous materials. In Canada they meet code 312 to operate.

SCRIMP process This Seeman Composites Resin Infusion Process (SCRIMP) is described as a gas-assist resin transfer molding process. As an example glass fiber fabrics/ thermoset vinyl ester polyester plastic and polyurethane foam panels (for insulation) are placed in a segmented tool. A vacuum is pulled with a bag so that a huge amount of plastic can be drawn into the mold (Marco process approach). Its curved roof is made separately and bonded to the box with mechanical and adhesive fastening. It is similar to various reinforced plastics molding processes. 

Spray-up Popular system with reinforced plastic production. An air spray gun includes a roller cutter that chops usually glass fiber rovings to a controlled short length before being blown in a random pattern (manually or automatically) onto a surface of the mold simultaneously the gun sprays catalyzed TS polyester plastic. The chopped fibers are plastic coated as they exit the gun s nozzle. The resulting, rather fluffy, RP mass is consolidated with serrated rollers to squeeze out air and reduce or eliminate voids. A closed mold... 

Phosphorus trichloride also reacts with glycol and ethylene oxide to form other a-hydroxyalkanephosphonates, serving as additives for polyurethane and polyester plastics to make these substances flame-resistant. 

Yang, L. and Kooker, D., Cured polyester plastic compositions derived from recycled polyurethanes, US Patent 5 859 167 1999. 

Mixed xylenes are used as an octane improver in gasoline and for commercial solvents, particularly in industrial cleaning operations. By far, most of the commercial activity is with the individual isomers. Para-xylene, the most important, is principally used in the manufacture of terephthalic acid and dimethyl terephthalate en route to polyester plastics and fibers (Dacron, films such as Mylar, and fabricated products such as PET plastic bottles). Ortho-xylene is used to make phthalic anhydride, which in turn is used to make polyester, alkyd resins, and PVC plasticizers. Meta-xylene is used to a limited extent to make isophthahc acid, a monomer used in making thermally stable polyimide, polyester, and alkyd resins. 

Clear polyester sheet stock and rods are available13 and, like reinforced polyester plastic, may be drilled, sawed, and machined. This clear plasic is harder than poly(methyl methacrylate) and much more solvent resistant than either po-lyfmethyl methacrylate) or polystyrene. As with all thermosetting plastics, it may not be heat-formed or solvent-bonded. However, bonding with epoxy cements is satisfactory. This plastic is claimed to give continuous service at 80°C and intermittent service up to 150°C. 

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