Thermal and dynamic mechanical relaxation behavior of stereoregular poly(2‐hydroxyethyl methacrylate)

Thermal, dynamic mechanical, and dielectric relaxation techniques were used to determine the relaxation behavior of isotactic and syndiotactic poly(2‐hydroxyethyl methacrylate) (pHEMA). Activation energies Ea were determined for the dielectric γ relaxation and compared with those of poly(2‐methoxyethyl methacrylate) (pMEMA) to determine the influence of hydrogen bonding on side‐chain relaxation processes. No difference in Ea was observed between syndiotactic pHEMA and atactic (predominantly syndiotactic) pMEMA. Isotactic pHEMA, however, had Ea + 1 kcal/mole higher than that of syndiotactic pHEMA. This was attributed to improved side‐chain packing in the isotactic polymer.