High-performance polymers Engineered thermoplastic with chemical

Acyl cations are involved as propagating species in the synthesis of poly-(ether ketone)s. Poly (ether ketone)s are a class of thermoplastic crystalline polymers that have many desirable properties that make them useful as high-performance engineering materials [153,154]. The poly(ether ke-tone)s with the most useful properties are actually para-linked poly(aryl-ether ketone)s (PAEKs). They have excellent chemical resistance to oxidation and hydrolysis, high thermal stability, and many useful mechanical properties. Unlike some other materials with similar properties they are readily melt processable using conventional equipment. In addition, their mechanical properties are not affected deleteriously by most solvents. These polymers are usually crystalline. PAEKs contain arene groups joined by ether and carbonyl linkages. For example, two commercial poly-(ether ketone)s are PEK and PEEK (Fig. 36). 

Polyoxymethylene (POM) is a semi-crystalline thermoplastic resin with high commercial importance as an engineering polymer [1]. POM is broadly used for manufacturing of construction details where high mechanical, thermal, chemical and electrical performance is required. However, novel POM-based materials are developed to find new application areas and withstand the competition with novel high performance engineering resins, e g., polyetheramides [2,3]. 

---