Liquid crystalline polymers: 2. Synthesis and thermotropic studies of poly(arylidene-ether)s containing a cyclopentanone moiety in the main chain

A novel series of poly(arylidene-ether)s containing cyclopentanone was synt hesized by polycondensation of 4,4'-diformyl-alpha,omega-diphenoxyalkane an d 4,4'-diformyl-2,2'-dimethoxy-alpha,omega-diphenoxyalkane with cyclopentan one. The polymers were characterized by elemental and spectral analyses, in herent viscosity, solubility and thermal analyses. Their thermotropic liqui d crystalline properties were examined by DSC, optical polarizing microscop y using a heated stage and thermogravimetric analyses. Almost all the polym ers exhibited thermotropic liquid crystalline properties. In most cases the mesophase extends up to 358 degrees C, where thermal decomposition prevent s further observations. In addition, the crystallinity of some polymers was examined by x-ray analysis; all showed some degree of crystallinity. The m orphology of one polymer was examined by scanning electron microscopy (SEM) .