Styrene Copolymer Foams

Copolymers of styrene and other monomers are also used in packaging foams. The most common is styrene-acrylonitrile (SAN) foam, which is a semirigid foam and offers better performance than PS foam in repeated drops and for heavy products (high static loads). The density of SAN foam is usually about 16 Ib/m (1 Ib/ft ). 

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Styrene copolymer foams, 23 404 Styrene copolymers, 23 366-367 properties of, 10 206t Styrene derivative polymers, 23 367-368 Styrene derivatives, 23 348-355 Styrene-diene block copolymers, 14 251 Styrene-divinylbenzene copolymers,... 

Mazzola et al used polyesters for foamed composites (6). Narkis et al (27) described foamed polyester composites made using random glass mat. Saidla et al (28) reported making foamed polyester composites using -inch glass fibers. Vinyl ester/styrene copolymer foams were developed by Olstowski and Perrish (10, 11). Vinyl ester-based hybrid-foam composites were developed by Frisch and Ashida (19). 

An outstanding property of EPS is its extremely low density (when compared to other processes), that by alteration of the preforming treatment can be varied according to the end use. Other types of plastics are employed to produce expandable plastic foam (EPF), including PE, PP, PMMA, and ethylene-styrene copolymers. They can use the same equipment, with only slight modifications. These plastics have different properties from those of EPS and open up different markets. They provide improved sound insulation, resistances to additional heat deformation, better recovery of shapes in moldings, and so on. 

Styrene (phenylethylene or vinyl benzene, C6H5-CH=CH2) is made from ethylene by reaction with benzene to form ethylbenzene, followed by dehydrogenation. Over 50 percent of manufactured styrene is polymerized to polystyrene for toys, cups, containers, and foamed materials used for insulation and packing. The rest is used to make styrene copolymers, such as styrene-butadiene rubber (SBR). 

Fig. 13. a TEM micrograph of a polyimide foam derived from a imide/a-methylstyrene triblock copolymer, b TEM micrograph of a polyimide foam derived from a imide/styrene copolymer... 

Styrene CH2=CH 6 Polystyrene (PS) —(-CH,—CH 6" Transparent and brittle used for cheap molded objects, e.g., Styron, Carlnex, Hostyren, Lustrex. Modified with rubber to improve toughness, e.g.. High impact Polystyrene (HIPS) and acrylonitriie-butadiene-styrene copolymer (ABS). Expanded by volatilization of a blended blowing agent (e.g., pentane) to make polystyrene foam, e.g., Styrocell, Styrofoam. 

Two SBR copolymers, (1) with of 53-75 wt% of styrene and (2) with 42-75 wt% of styrene Cmed foams for shoe soles with high shock absorption Hashimoto and Ohashi 1985... 

Cladding (siding) GRP, PVC, foamed unplasticised PVC (PVC-U), acrylonitrile-butadiene-styrene copolymer (ABS) as a blend of ABS/acrylic/PVDF... 

This technique has found the following applications in addition to those discussed in Sections 10.1 (resin cure studies on phenol urethane compositions) [65], 12.2 (photopolymer studies [66-68]), and 13.3 (phase transitions in PE) [66], Chapter 15 (viscoelastic and rheological properties), and Section 16.4 (heat deflection temperatures) epoxy resin-amine system [67], cured acrylate-terminated unsaturated copolymers [68], PE and PP foam [69], ethylene-propylene-diene terpolymers [70], natural rubbers [71, 72], polyester-based clear coat resins [73], polyvinyl esters and unsaturated polyester resins [74], polyimide-clay nanocomposites [75], polyether sulfone-styrene-acrylonitrile, PS-polymethyl methacrylate (PMMA) blends and PS-polytetrafluoroethylene PMMA copolymers [76], cyanate ester resin-carbon fibre composites [77], polycyanate epoxy resins [78], and styrenic copolymers [79]. 

More recently, filled polyethers (so called polymer polyols ) have been introduced. These contain dispersed organic filler such as acrylonitrile-styrene copolymer or polyurea, some of which is grafted on to the polyether chain. Filled polyethers are used principally for flexible foams of high resilience. 

Uses DispersanL emulsifier, solubilizer for emulsion polymerization of acrylates, styrene acrylic, vinyl chloride, vinylidene chloride and vinyl acetate copolymers foaming agent for mech. latex foaming, caqiet and upholstery cleaners air entraining agent emulsifier in mfg. of food-contact articles food-contact paper/ paperboard... 

The combination of stmctural strength and flotation has stimulated the design of pleasure boats using a foamed-in-place polyurethane between thin skins of high tensUe strength (231). Other ceUular polymers that have been used in considerable quantities for buoyancy appHcations are those produced from polyethylene, poly(vinyl chloride), and certain types of mbber. The susceptibUity of polystyrene foams to attack by certain petroleum products that are likely to come in contact with boats led to the development of foams from copolymers of styrene and acrylonitrUe which are resistant to these materials... 

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