Polyamides: Developments and Applications Towards Next-Generation Engineered Plastics

摘要

With its introduction as a moulding material in 1940s, the polyamides (PAs) have been transformed into true engineering thermoplastics over a period of time. Owing to high thermal and chemical resistances in combination with exceptional mechanical durability, these classes of polymers have come a long way in establishing themselves as materials of choice for diverse application types. The recent technical advancements through the incorporation of novel functionalities to the basic amide structure of PAs has further enhanced their performance which contributed for an exponential growth in high-demand uses, especially in automotive and electrical industries. By keeping in view of the typical role played by PAs in various industrial sectors, this review article is designed to start with a brief historical background, which indulges into a comprehensive discussion to explore the recent developments in the research and design of next generation PA compounds and their engineered composites. Apart from the currently operating, more dominant and conventional class of polyamide-6 and polyamide-66, this work further focusses towards the development of new class of amides through selective compounding of different diamine and dicroboxlyic acid monomers, especially intended for niche markets. In addition, we also discussed about some reactive and long fibre-reinforced PA products developed by global commercial entities to substitute certain metal-based appliances in house-hold and precision machine products. Finally, the very recent research activities involved in the synthesis of bio-based PAs and their composites are also presented here.