Mechanical Properties polyquinolines

PROPERTIES OF SPECIAL INTEREST The Structure of polyquinolines can be altered from a semirigid chain to a rigid one during the synthesis. Although largely an amorphous polymer, some substituted rigid-rod members exhibit crystallinity in low amounts. Polyquinolines are found to posses excellent thermal and oxidative stability, good mechanical properties, low dielectric constants, low values of moisture absorption, and low thermal expansion coefficients. 

In an effort to increase the processibility of polyquinolines, fluoromethylene groups have been successfully incorporated into the chain in place of Ar in the bis (ketomethylene) moiety (94). In fact, a small percentage of perfluorobutylene groups in the polyquinoline chain was sufficient to decrease the T significandy while still retaining other desired mechanical and thermal properties. Another approach was to prepare a series of oligomeric polyquinolines containing pendent biphenylenes and capped with either phenyl or biphenylene moieties (95). A representative list of different polyquinoline backbones and their properties appears in Table 3. 

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