RIGID BACKBONE POLYMERS .4. SOLUTION PROPERTIES OF 2 LYOTROPIC MESOMORPHIC POLY(ISOCYANATES)

Solution properties of poly(hexyl isocyanate) (PHIC) and poly(50% butyl + 50% p-ani-sole-3-propyl isocyanate) (PBAPIC) polymers were evaluated by Mw, Mn, viscosity, and microscopic techniques. The results show: (a) both polymers form liquid crystals above a certain critical concentration; and (b) both polymers partition into more concentrated anisotropic and more dilute isotropic phases (the anisotropic phase is composed of the higher molecular weight fraction of the polymer and the isotropic phase contains the lower molecular weight portions of the polymer). Microscopic observations of isotropic inclusions in the anisotropic solution phase of PHIC reveal the former to possess angular shapes. The development of this angularity is explained as resulting from the growth of the isotropic inclusions. © 1979, American Chemical Society. All rights reserved.