Melt stabilizers 606 High Performance Polymers

S. Campbell and D. Scheiman, Orientation of aromatic ion exchange diamines and the effect on melt viscosity and thermal stability of PMR-15/silicate nanocomposites. High Performance Polymers, 14 (2002), 17-30. 

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). 

Polymers organized in this unusual state behave as hexagonal mesophases similar to those observed in the bulk at suitable temperature/pressure conditions and adopt the extended chain conformation. Polymers included in nanochannels were discovered a few decades ago [33,34], but the mesomorphic properties and the stabilizing interactions were established much later by advanced spectroscopic techniques [35-41]. The preparation of novel macro-molecular adducts, melting at temperatures as high as 350 °C and sustained by CH- 71 intermolecular interactions, has been a success of supramolecular chemistry in fabricating high performance nanostructured materials [42]. 

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