Engineering Plastics

The chapter discusses the plastics that are considered engineering plastics and the reasons for the classification. The plastics will include nylon, polycarbonate, polyethylene terephthalate, polybutylene terephthalate, thermoplastic polyurethane, acrylonitrile butadiene styrene, and Styrene acrylonitrile. They also include acetal, polytetrafluoroethylene, polyphenylene oxide, Polyphylene sulfide, polyether-ether-ketone, liquid crystal polymers, copolymers, and blends. Engineering thermoplastics are plastics that have higher mechanical and thermal properties than commodity plastics. They can sometimes replace metal parts. They can use conventional plastic molding operations. They usually can be painted. They, typically, have higher costs per pound than commodity plastics. Polyimides were developed by Du Pont in 1962. Polyimides are obtained from a condensation polymerization of aromatic diamine and an aromatic dianhydride. Polyarylesters repeat units feature only aromatic-type groups between ester linkages. Polyarylates can be called wholly aromatic polyesters and can be based on a combination of suitable chemicals.