Dielectric investigation of ester group rotation of PEMA and PBiBMA at radio and microwave frequency

The dielectric absorption of dilute solutions of poly (ethyl-methacrytate) (PEMA) and poly(n-butyl iso butyl methacrylate) (PBiBMA) in benzene has bee n studied at radio and microwave frequency ranging from 10 kHz to 3 MHz and 10 GHz respectively and at temperatures between 288 to 328 K. Enthalpies o f activation obtained using frequency variation for PEMA and PBiBMA have be en found to be 9.6 and 27.2 kl/mol respectively. The data evaluated using f requency variation method for both the systems are also supported by the me asurements carried out at microwave frequency using concentration-variation technique. Delta H epsilon observed here are expected to be arising from t he internal rotation involving the - C [GRAPHICS] ester group.