Synthesis and characterization of side-chain liquid crystalline polyoxetanes containing 4-(alkanyloxy)phenyl 4-pentylbenzoate side groups

The synthesis and characterization of side-chain liquid-crystalline polyoxetanes containing 4-(alkanyloxy)phenyl 4-pentylbenzoate side groups is presented. Differential scanning calorimetry, polarizing optical microscopy and X-ray diffraction measurements were used to characterize the mesomorphic properties of the polyoxetanes. Those polymers with three to five methylene units in the spacers exhibit the enantiotropic smectic A and a nematic phaser, whereas the polymers with longer spacers (n = 6 or 12) display polymorphism of smectic phases. The polyoxetane backbones are amorphous in nature. No side chain crystallization occurred for any of the polyoxetanes synthesized in this study.