Poly containing heterocyclic units

Poly(Arylene Ether)s Containing Heterocyclic Units... 

During the last several years, a significant effort has been devoted to incorporating heterocyclic units into the backbone of PAE. When heterocyclic units are placed within the arylene ether polymer chain, certain properties such as strength, modulus and glass transition temperature (Tg) generally increase. Aromatic nucleophilic displacement and electrophilic reactions have been used to synthesize poly(arylene ether)s containing heterocyclic units (PAEH). 

Poly(arylene ether benzimidazole)s have received more attention than any other PAE containing heterocyclic units. This is due primarily to their unique combination of properties even at relatively low molecular weights and their potential for use in several high performance applications. The initial report in 1991 involved polymers from the reaction of 3 different bis[(4-hydroxy-phenyl)benzimidazole]s with various activated aromatic difluoro monomers as shown in Eq. (10) [37]. The bis[(4-hydroxyphenyl)benzimidazole]s were prepared from the reaction of aromatic bis(o-diamines) and phenyl-4-hydroxybenzoate in diphenyl sulfone. The use of 4-hydroxybenzoic acid would obviously reduce the... 

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