Abstract

This article covers semicrystalline thermoplastic polyesters and their applications as molding resins. The principal polymers described are PET, PBT, PEN, PTT, PCT, thermoplastic elastomers of the PBT–PTMEG-T type, and liquid crystalline polymers. The raw materials for various polyesters and their production are described and general routes to polyester polymer synthesis outlined. Individual polyesters are described in more detail with particular reference to special features of their polymer chemistry. PET stretch blow-molded bottles and containers are a very large market and the production of PET bottle resin by continuous polymerization and solid-state polymerization is described together with an outline of the stretch blow-molding process. Physical properties, polymer characterization and mechanical properties together with details of polymer injection molding are described.

Particular reference is given to the growing demands for PCT of new electronic and electrical fabrication techniques such as surface mounting technology and its requirements for high temperature polymer properties. PBT polymer is described in detail. Flame-retardant additives are described and how they affect polymer performance. Safety and health factors for the polymers in use are discussed.

Liquid-crystal polymers are relatively new high performance thermoplastics. The nature of the mesophase state and how LCPs differ from conventional materials is described. The LCP polymer synthesis is outlined and physical and mechanical properties of several commercial LCP polymers are given.