Kinetically controlled phase transitions in side chain liquid crystalline polymers

The kinetics of phase transitions in side chain liquid crystalline homo- an d copolymers is studied using differential scanning calorimetry. For the mo st cases, the Avrami treatment of kinetic curves gives evidence of diffusio n-controlled mesophase formation while a crossover to free two-dimensional phase growth has been observed for a smectic copolysiloxane. All the polyme rs show a linear increase in transition temperatures upon annealing tempera ture but a corresponding decrease in transition enthalpies. Application of the "slow" phase transitions to the photorecording in dyed copolymers is di scussed.