Plastics. Also polystyrene

Polystyrene (PS), 7 610t 23 326, 348, 358. See also Polystyrenes Styrene Styrene plastics biodegradation of, 23 376 brominated, 11 470-474 chain transfer to, 23 383 colloidal suspensions, 7 275 crystalline syndiotactic, 23 388 decomposition of, 14 109 effect of orientation on oxygen permeability, 3 393t... 

Modules Multicelled seed trays—also known as module trays—are available in plastic and polystyrene. The plastic ones are easier to remove plants from, and thus use again. Each seedling grows in its own individual "mini-pot," so its root system is not disturbed on transplanting. 

Paramount among the outlets for petroleum raw materials outside the field of fuels and lubricants are the elastomers and plastics. It is expected that synthetic rubber production in 1951 will exceed 800,000 long tons (1.8 billion pounds) while, during the same period, nearly two billion pounds of plastics also will be produced. It has been demonstrated to the American consumer that synthetic rubber is equal or superior to the natural product for many applications, and plastic products such as nylon fabrics, polyvinyl chloride upholstery, and polystyrene toys and gadgets are now considered a part of our way of life. 

The behavior of plasticizers in a polymer has already been examined by Wiirstlin (16) with dielectric measurements. However, this method is not sensitive enough to detect the plasticizer behavior in the system at small plasticizer concentrations. Luther and Weisel (12) have also pointed out this fact as a result of their DC measurements of PVC-plasticizer systems. The following measurements deal with the behavior of plasticizers in polystyrene. 

Substitute for Conventional Vulcanized Rubbers, For this application, the products are processed by techniques and equipment developed for conventional thermoplastics, ie, injection molding, extrusion, etc. The S—B—S and S—EB—S polymers are preferred (small amounts of S—EP—S are also used). To obtain a satisfactory balance of properties, they must be compounded with oils, fillers, or other polymers compounding reduces costs. Compounding ingredients and their effects on properties are given in Table 8. Oils with high aromatic content should be avoided because they plasticize the polystyrene domains. Polystyrene is often used as an ingredient in S—B—S-based compounds it makes the products harder and improves their processibility. In S—EB—S-based compounds, crystalline polyolefins such as polypropylene and polyethylene are preferred. Some work has been reported on blends of liquid polysiloxanes with S—EB—S block copolymers. The products are primarily intended for medical and pharmaceutical-type applications and hardnesses as low as 5 on the Shore A scale have been reported (53). 

This chapter reports successful initial efforts to bond wood in the presence of hydrophobic plastic material [polystyrene (PS)] using well-defined and tailored cellulose-polystyrene graft polymers as compatibilizers or interfacial agents. The synthesis of these tailored cellulose graft polymers is also presented. 

It may also be possible to eventually extend this bonding concept to the preparation of flakeboards and other wood-base composite materials. If plastics like polystyrene are incorporated into the composite matrix, and successful bonding between the wood and plastic is developed through the graft polymers, the three-dimensional network of plastic material throughout the composite matrix may lead to enhanced physical and mechanical properties as well as improvements in dimensional stability (Figure 2). 

Cellular plastics, mainly polystyrene, are used for display and novelty pieces because of ease of fabrication, light weight, attractive appearance, and low cost. Phenolic foam is used in floral displays, where it can hold large amounts of water for long periods. Polyurethane and polystyrene foams are also used in other floral applications. Cellular poly(vinyl chloride) is used in toys and athletic goods. 

Plasticizers perform this function if a single plasticizer solvates the dissimilar major components of a blend. Phthalate esters help to stabilize mixtures of poly(vinyl chloride) and poly(melhyl methacrylate) for example. These materials are also plasticizers for polystyrene, and stable blends of this polymer with poly(vinyl chloride) can be made by adding dioctyl phthalate to a blend of polystyrene and rigid PVC. 

For bonded joints with crystal clear plastics like polystyrene and acrylic glass to metals, it is also possible to apply radiation-curing adhesives (Sections 4.3.2 and 9.3.3). 

The development of plastics also reflects economic history. Restrictions on imported latex, wool, silk and other natural materials to Europe during the Second World War resulted in the rapid development of alternative synthetic plastics. Table 1 shows that between 1935 and 1945, many new polymers were introduced including polyethylene, polyamides, poly(methyl methacrylate), polyurethanes, poly(vinyl chloride) (PVC), silicones, epoxies, polytetrafluoro-ethylene and polystyrene. Polyethylene was incorporated into radar systems while PVC replaced the limited stocks of natural rubber as cable insulation. 

Materials for sintering and melting are plastics, metals, or ceramics. Plastics may be unfilled or filled with glass or aluminum spheres or egg-shaped geometries to improve properties like durability and thermal resistance. Also nanoscale particles are used. Unfilled plastics are mostly commodities like semicrystalline polyamides from the PAl 1 or PA12 type or amorphous plastics like polystyrene (PS). Engineering plastics like PEEK are available. 

Tris(2-chloroethyl phosphate) n. (CH2CI CH20)P0. a plasticizer for polystyrene, cellulosics, and vinyls. It is also effective as a flame retardant for unsaturated polyesters and polyurethane foams. 

The suspension polymerisation approach is often used in the production of polyvinyl chloride dispersions for use in plastic pipes. Polystyrene and styrenic copolymers are also produced by suspension polymerisation. The polystyrene beads are often prepared by suspension polymerisation for use as packing material in gel permeation chromatography (GPC) columns. Ion exchange resin beads are also commonly produced by suspension polymerisation. Because suspension beads are relatively large, it is easier to separate the polymer by coagulation than in the case of emulsion polymerisation. 

An example of the latter is Dow s development of syndiotactic polystyrene, which has the properties of an engineering plastic. Also important is the incorporation of comonomers in a highly uniform manner. Again, Dow has produced an 80% ethylene/20% octane elastomer (89). Metallocene polymers have mainly been used in higher priced specialty applications (). 

Quartz cuvettes can also be used without a problem. For plastic cuvettes, polystyrene seems to have optimal performance due to limited nonspecific binding of proteins and inhibitors to the surface. 

Plastic materials have become basic and indispensable in our life. To protect against contamination and conserve them, food products are distributed in different plastic packages bags, bottles, boxes, etc. that contain all kinds of edible products liquid (water, milk, cold beverages) or solid (fruit, meat, fish, frozen foods, etc.). The group of commercial plastics, also termed commodity plastics, consists of the most used polymers in terms of volume and number of applications. They are mainly polystyrene (PS), polypropylene (PP), high-and low-density polyethylene (HDPE, LDPE), polyethylene terephthalate (PET) and, in lower proportion, polycarbonate (PC) [71. 

Nucleating agent, cell-control These agents promote symmetrical, cohesive expansion of cells within foamed polyurethane and polystyrene plastics also to a limited extent in polyethylene and polypropylene plastics. 

Tricresyl Phosphate n (TCP, TCF, tritolyl phosphate) (CH3C6H4)3P04. One of the most important and earliest of all commercial plasticizers. Also suitable for cellulosics, alkyds, and polystyrene. Like all other phosphate plasticizes, TCP imparts flame retardance and fungus resistance, even when used in amounts as low as 5% of the total plasticizer content. TCP and cresyldiphenyl phosphate are the plasticizers most widely used for these properties. Bp, 430-440° C flp, 216°C (420°F). Known also as TCP. Syn Tritolyl Phosphate. 

Eversorb 90 is a hindered amine light stabilizer. Even with rather low contents of Eversorb 90 in plastic formulation, it still exhibits superior light stabilization. Furthermore, its anti-UV effect would be significantly increased by the combinaton with UV absorbers such as Eversorb 71, Eversorb 73 and Eversorb 12 in various polymers. Eversorb 90 is particularly suitable for using in Polypropylene, High Density Polyethylene and ABS. It is also effective to protect the following plastics Polyurethane, Polystyrene, Polyester, Polyamide, Coatings, Adhesives and Rubbers... 

The annual production of styrene in the United States is approximately 1 2 X 10 lb with about 65% of this output used to prepare polystyrene plastics and films Styrofoam coffee cups are made from polystyrene Polystyrene can also be produced m a form that IS very strong and impact resistant and is used widely m luggage television and radio cabinets and furniture... 

Eoamed polystyrene sheet has exceUent strength, thermal resistance, formabUity, and shock resistance, as weU as low density. It is widely known for its use in beverage cups, food containers, building insulation panels, and shock absorbent packaging. Polystyrene products can be recycled if suitable coUection methods are estabUshed. Eoamed polystyrene sheet can also be easily therm oformed (see Styrene plastics). 

Foamed plastics (qv) were developed in Europe and the United States in the mid-to-late 1930s. In the mid-1940s, extmded foamed polystyrene (XEPS) was produced commercially, foUowed by polyurethanes and expanded (molded) polystyrene (EPS) which were manufactured from beads (1,2). In response to the requirement for more fire-resistant ceUular plastics, polyisocyanurate foams and modified urethanes containing additives were developed in the late 1960s urea—formaldehyde, phenoHc, and other foams were also used in Europe at this time. 

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