ORIENTATIONAL PHENOMENA IN LY[BIS-(2,2,3,3,3-PENTAFLUOROPROPOXY)-PHOSPHAZENE] MESOPHASE

The thermotropic behavior and morphology of s-(2,2,3,3,3-pentafluoropr opoxy)phosphazene](PPPh) have been investigated by various methods suc h as: differential scanning calorimetry, scanning electron microscopy and X-ray diffraction. It was shown that a polymer is able to exist in a four phases. A wide-angle X-ray temperature analysis indicates a mo noclinic crystalline form for the first (low temperature) phase, the o rthorhombic crystalline modification for the second one and the two-di mensional pseudohexagonal mesophase lattice for the mesomorphic state followed by the isotropic melt. Transition from the crystalline into t he mesophase state in the range 85-100-degrees-C is observed. PPPh mac romolecules in the mesomorphic state are found to be oriented in the e xtrusion direction.