Vinyl-Polymers and Polyacrylates

Polystyrene (PS) (Table 5.3.12) is produced almost exclusively in-substance, for example, by using a production tower (see Topic 5.3.7 for details). The polymer is transparent and readily processable in molding techniques. However, pure PS is somewhat brittle and not very resistant to organic solvents. Therefore, copolymers with substantial shares of PS are of great industrial relevance. Examples are PS-acrylonitrile (SAN), PS-butadiene rubber (SBR), and PS-butadiene-acrylonitrile (ABS) copolymers. Another important apphcation form of PS is PS foams (Styropor ). The latter are used for the thermal insulation of buildings as the air enclosed in the foam reduces the heat conductivity of the material to very small values. 

Pdy(methyl methacrylate) (PMMA, Plex as ) is produced by radical polymerization of methyl methacrylate. The outstanding property of PMMA is its brilliant. 

Hard PVC tubing, window frames srfi PVC transport belts, toys, packaging systems 

Glass in buildings and vehicles, optic instruments and devices (lenses, prisms, reflectors) 

The different mechanisms of polymerization can be divided into two general groups, chain-growth polymerization and step-growth polymerization. 

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