Edward Norman Peters

Engineering Thermoplastics—Materials, Properties, Trends

Engineering thermoplastics and advanced engineering thermoplastics or ultrapolymers comprise a special, high-performance segment of synthetic plastic materials that offer premium properties. When properly formulated, ETP may be shaped into mechanically functional, semiprecision parts or structural components. This chapter presents a historical overview of the development of engineering thermoplastics covers the early pioneers in the field up to recent advances in engineering thermoplastics. In addition, it covers a broad range of chemistries, types of polymers, their properties, key performance features, and a brief description of targeted markets.

2 – Engineering Thermoplastics

Publisher Summary Engineering polymers comprise a special, high-performance segment of synthetic plastic materials that offer premium properties. Polyamides, commonly called nylons, were the first commercial thermoplastic engineering polymers and are the prototype for the whole family of polyamides. Nylon was a new concept in plastics for several reasons. Because it was semicrystalline, nylon underwent a sharp transition from solid to melt; thus it had a relatively high service temperature. In addition, nylons prepared from aromatic diamines and aromatic dicarboxylic acids can lead to very high-heat aromatic nylons (aramids). After nylon, the next engineering polymers to be commercially introduced were polyacetals. Polyacetals are polymerized from formaldehyde and are called polyoxymethylenes (POM). Key areas of use for POMs are industrial and mechanical products that include molded or machined rollers, bearing, gear, conveyor chains, and housings. POMs are widely used in plumbing and irrigation because they resist scale build up and have excellent thread strength, creep resistance, and torque retention. The aromatic polycarbonates (PC) were the next engineering polymers to be introduced. In the mid-1966 GE introduced a family of PPE blends with high impact polystyrene (HIPS), under the Noryl trademark. This combination of total compatibility with PS and the added toughness from HIPS was the key to commercial success. Varying the PPE/HIPS ratio results in a wide range of high temperature, easy to process, tough, dimensionally stable plastics. Noryl resins became the worlds most successful and bestknown polymer blends because combinations of PPE resins and styrene polymers.