THERMAL AAD BIPHASIC BEHAVIOR OF A SIDE-CHAIN SMECTIC POLYACRYLATE

The thermal and biphasic behaviour is reported for a side-chain smecti c polyacrylate having a number average molecular weight of 59000g mol( -1) and a first polydispersity index of 1.9. Evidence is provided for the existence of smectic Ad and smectic Al mesophases, the former bein g enantiotropic and the latter monotropic. The biphasic behaviour was studied by DSC by annealing the polymer inside the apparent biphasic g ap associated with the smectic Ad-isotropic transition. A biphasic tem perature range in which isotropic and smectic Ad phases coexist at equ ilibrium was revealed, and the thermodynamic width of this biphasic re gion was estimated to be about 2.0 K.