Comparative Study of Shape Memory Bisphenol A and Bisphenol F Cyanate Ester Systems

A shape memory polymeric precursor, viz. phenol-telechelic poly(ε-caprolactone) (PCLOH), was synthesized by reacting para-hydroxybenzoic acid with poly(ε-caprolactone) (PCL) diol. The polymer was characterized by FTIR, ester value and SEC. Novel thermoset polymers showing shape memory properties were synthesized by reacting diglycidyl ether of bisphenol A (DGEBA) and PCLOH with two cyanate ester resins, namely bisphenol A cyanate ester (BACE) and bisphenol F cyanate ester (BFCE). The cure characteristics of the blends were evaluated by DSC and FTIR, and their fracture morphology by SEM. Blends with a fixed proportion of epoxy, PCLOH and the different cyanate esters were studied for their flexural, dynamic mechanical, thermal and shape memory properties. These epoxy-cyanate ester systems possess good thermal, mechanical and shape memory characteristics for potential use in smart actuator development. The advantages of this system include a controllable transition temperature and better processability than traditional shape memory thermoset systems.