Polyphthalamide plastics

As with the aliphatic polyamides such as nylons 6 and 66, the polyphthalamides were developed as plastics materials only after their sucessful use in the field of fibres. Such materials were introduced in 1991 by Amoco under the trade name of Amodel. 

The manufacturers stress ease of processing as a particular feature of the material. Recommended melt temperatures are in the range 320-340°C and mould temperatures are 135-165°C. Mould shrinkage of glass-filled grades is usually of the order of 0.2-0.4% in the flow direction and up to twice this value in the transverse direction. The materials are notable for their ability to withstand vapour phase and infrared soldering processes. 

The polyimides have the characteristic functional group below and are thus closely related to the polyamides. However, the branched nature of the 

By the mid-1970s there were over 20 suppliers in the United States and Western Europe alone although some companies have now withdrawn from the market. 

In this section discussion will be confined to the true polyimides whilst the modified materials will be considered in Section 18.14. 

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These PPA heat resistant, high performance plastics have been used successful in different applications such the auto engine block. BP Amoco reports that after seven years and 85,000 miles of actual vehicle use, a Dodge Neon 2.0 liter thermostat housing molded from BP s PPA (polyphthalamide) showed no measurable dimensional variations, no surface degradation, and no decline in the performance of the plastic. In 1994, BP model A-113 3 HS (a 33wt% glass-filled, heat-... 

Harris, J.H. and Reksc, J.A., Polyphthalamide, in Modem Plastics Encyclopedia Handbook, McGraw-Hill, New York, 1994, p. 47. 

POSS polyhedral oligomeric silsesquioxanes PP polypropylene PPA polyphthalamide ppb parts per billion PPG polyphthalate carbonate PPE polyphenylene ether pph parts per hundred ppm parts per million ppmv parts per million by volume ppmwt parts per million by weight PPO polyphenylene oxide PPPS polyphenylene sulfide sulphone PPS polyphenylene sulfide PPSF polyphenylsulfone PPSU polyphenylene sulphone PPVC plasticized polyvinyl chloride PR public relation PS polystyrene... 

Engineering and high performance plastics markets are characterised by a high degree of concentration. The top three world suppliers of polycarbonate (GE Plastics, Bayer and Teijin), for example, control around 70% of total supply. The three leading polyamide suppliers control 55% of world supply and the largest three ABS producers account for 57% of world production. The most extreme cases are polyetherimide, polyphthalamide and PSU, where there are only one or two world suppliers of each t5 e of plastic. 

During the 1980s and 1990s, the pace of research and commercialisation of high-temperature plastics accelerated dramatically. The thermoplastic resin manufacturers introduced many new materials based on imide, sulfone, and ketone-based polymers. These include polyetherimide (1982) and polyphthalamide (1991). Polyketones and liquid crystal polymers were also commercialised in the 1990s. 

The main filled engineering plastics are polyamides, thermoplastic polyesters, poly(phenylene oxide)/polystyrene alloy, poly(phenylene sulfide), polyphthalamide, and polysulfones. 

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