Radio and microwave dielectric properties of PMA and PiBMA in solution

The dielectric absorption of dilute solutions of poly (methyl acrylate) (PM A) and poly (isobutyl methacrylate) (PiBMA) in benzene have been studied in the radio and microwave frequency region of 10 to 800 kHz and 10 GHz respe ctively and at five different temperatures 303, 313, 323, 328 and 333 K. Us ing frequency variation technique enthalpies of activation for PMA and PiBM A have been found to be 11.4 and 26.1 kJ/mol respectively. For both the sys tems, data evaluated using frequency variation method were also supported b y the measurements carried out using concentration variation method at the microwave frequency. The enthalpies of activation DeltaH epsilon observed h ere were expected to be arising due to the internal rotation involving the ester group- [GRAPHICS]