Styrenic plastics rates

As a measure of the level of sophistication of the industry the types of polymers consumed was as shown in figure 2. Others are mainly engineering thermoplastics (ETP), such as nylon, polyacrylates, polyacetals, polycarbonates, polyesters, and polpropylene oxide etc... These ETP s are growing at rates up to 20%. The main uses for plastic products are computer and business machine parts as well as design engineered products. The consumption of styrenic plastics (polystyrene acrylonitrile butadiene styrene - ABS) is high, relative to polyolefins, because of their demand in electric/electronic end-uses. 

They were able to observe that inereased styrene eoneentrations reduces the polymerization rates of both methaerylate and styrene due to an inerease in the termination rate and due to flie stability of the styryl radical. Raising styrene concentrations also inereases the final methacrylate conversion, but the final styrene conversion decreases because styrene plasticizes the network, allowing methacrylate conversion to rise at higher styrene concentrations. The final concentration of radicals is reduced at higher styrene concentrations, because of an increase in the bimolecular termination rate for networks with low cross-link densities. The proportion of styryl radicals trapped in the vitrified matrix was found to be markedly higher flian the proportion predicted from the ratio of styrene monomer in the feed resin or from the copolymerization rate constants... 

Fig. 10. Viscosity vs shear rate for solutions of a styrene—butadiene—styrene block copolymer (42). A represents cyclohexanone, where c = 0.248 g/cm (9-xylene, where c = 0.246 g/cm C, toluene, where c = 0.248 g/cm. Courtesy of the Society of Plastics Engineers, Inc.

ABS plastic, a polymer consisting of polybutadiene spheroids is dispersed in a continuous phase of poly(styrene—acrylonitrile). The chromic acid attacks the polybutadiene at a much higher rate than the continuous phase. This gives an excellent microroughened surface with superior metal-to-plastic bond strength. A typical recommended formulation consists of 20 vol % sulfuric acid, 420 g/L chromic acid, and 0.1—1.0% of a fluorocarbon wetting agent. The plastic is treated with this formulation for 6—10 min at 60—65°C. 

This comprehensive article supplies details of a new catalytic process for the degradation of municipal waste plastics in a glass reactor. The degradation of plastics was carried out at atmospheric pressure and 410 degrees C in batch and continuous feed operation. The waste plastics and simulated mixed plastics are composed of polyethylene, polypropylene, polystyrene, polyvinyl chloride, acrylonitrile butadiene styrene, and polyethylene terephthalate. In the study, the degradation rate and yield of fuel oil recovery promoted by the use of silica alumina catalysts are compared with the non-catalytic thermal degradation. 9 refs. lAPAN... 

Another significant trend is the current program to increase the production of benzene from petroleum 16). Increasing requirements for the production of styrene, phenol, and other intermediates have made it essential that new sources be found to supplement current supplies of this aromatic hydrocarbon, and the only apparent source is from petroleum processes. To meet current needs of the military and civilian program the United States Petroleum Administration for Defense has been asked to increase petroleum benzene from the current rate of 12,000,000 gallons to 100,000,000 gallons per year 84). Present production from petroleum is small in comparison with that from other sources, but these proposed expansions may add materially to the output of petroleum-derived intermediates that will ultimately go to the manufacture of plastics and synthetic rubber. 

Suitable Plastics Acrylics, polystyrenes, cellulose acetates, cellulose buy rates, ionomers, rigid vinyls, polycarbonates, and medium-impact styrenes. 

Plasticizers are used in combination with cellulosics, vinyls, acrylic, and styrene resins, as well as polyvinylacetate, polyamides, polycarbonate, and other synthetic and natural resins. Because PVC consumes about 70% of all plasticizers produced, the plasticizer market is closely related to the vinyl resins production. During the last ten years, the vinyl market grew at an average rate of 18% per year and has reached 1.6 billion pounds in 1964. The growth in vinyl resins and plasticizer production was paralleled by a drop in resin price and a shift towards more effective and less expensive plasticizers. 

Polyolefin (PO) foams are tough, flexible, and resistant to chemical and abrasion however, they are characterized by a low inherent fire resistance and hence quite high amounts of flame-retardants are needed to fulfill fire safety requirements. Therefore, when fire requirements are stringent, generally styrene and engineered plastics are used in spite of polyolefin foams because, for example, for complying UL 94 V-0 rating, 30%-40% fire retardant is normally required for PO foams while only 10%-20% FR additives are required for styrenic foams.91... 

Styrenic polymer foams have been commercially accepted in a wide variety of applications since the 1940s [1,4]. The total usage of polystyrene foams in the United States rose from about 4.10 x 105 metric tons in 1982 to an estimated 5.35 x 105 metric tons in 1987. It is expected to grow at a rate of 3-4% for the next several years [5]. For example, a recent Fredonia report on foamed plastics estimates that the 2008 volume will be 10.77 x 105 metric tons [6]. 

Blends of copolymers of styrene and acrylonitrile and butadiene and acrylonitrile called ABS plastics which are more ductile than polystyrene, are now used at an annual rate of almost 500 thousand tons. Terpoljrmers of styrene, acrylonitrile and maleic anhydride (Cadon) have heat deflection points above lOOOC.Q)While the physical properties of both ABS and the maleic anhydride terpolymers are superior to polystyrene, the improvements are not sufficient to classify them as high performance plastics. 

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