Poly moulding materials

The properties of three types of poly(methyl methacrylate) (sheet based on high molecular weight polymer, lower molecular weight injection moulding material and a one-time commercial copolymer) are given in Table 15.1. 

Table 25.7 Some properties of poly(ethylene terephthalate) moulding material ( Amite ) (ASTM Test Methods unless otherwise stated.)...

For an aliphatic polyester, poly(pivalolactone) has a rather high of 245°C and for such a an unexpectedly low of -10°C. It is also claimed to have good hydrolysis resistance for a polyester and this appears to be one of the reasons for its manufacture on an experimental scale by Shell with a view for use as both a fibre and as a thermoplastics moulding material. 

Polymeric Beads, Expandable Polystyrene Beads, Expandable Plastics Moulding Compound A moulding material in bead or granular form consisting predominantly of polystyrene, poly(methyl methacrylate) or other polymeric material and containing 5% to 8% of a volatile hydrocarbon which is predominantly pentane. During storage a small proportion of this pentane is released to the atmosphere this proportion increases at elevated temperatures. IMO 9036... 

Polyester polymers are materials which exhibit various chemistries but all contain ester linkages in the polymer chain. They have attained industrial importance as moulded materials, fibres, packaging film and as structural materials which are reinforced with fibres and fillers. Chemists, John Rex Whinfield and James Tennant Dickson, employees of the Calico Printer s Association of Manchester, patented polyethylene terephthalate in 1941, after advancing the early research of Wallace Carothers. Poly (ethylene terephthalate) is the basis of polyester fibres and fizzy drinks botdes. The first polyester fibre known as Terylene was also developed in 1941. 

Ultem 1000 26 (Fig. 13) marketed by General Electric is a poly(ether-imide) representative of a series of thermoplastic polyimides that can be used as adhesives or moulding materials for applications at moderate temperatures T = 220°C). 

The major commercial interest continues to be centred on poly(ethylene terephthalate) 2GT and its use in fibres, films, and as a moulding material. Poly(tetramethylene terephthalate) 4GT has, however, found use recently as a moulding compound, and the lower members of the aliphatic series continue to find use in urethane technology. 

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