BASIC IDEAS OF MICROWAVE PROCESSING OF POLYMERS

The objective of this effort has been to investigate the relationship between polymer structure and microwave absorptivity. Dielectric loss factor, epsilon''. loss tangent, tan delta, and oscillator strength, ( epsilon(S) - epsilon(infinity)), were used to evaluate potential mater ial processability under applied microwave radiation. Numerous polymer ic materials varying in chemical and physical structures were irradiat ed in a low power (< 100W) electric field at 2.45 GHz. Electromagnetic radiation was applied as either traveling or resonant wave modes in c ylindrical and rectangular wave-guides. In general, heatability was fo und to be a direct function of the dielectric loss dispersion dependen ce on temperature and frequency. The dielectric loss factor obtained a t low frequency measurements was found to be directly proportional to the heatability of polymers. A WLF plot was used to predict the shift of dielectric loss maxima into or out of the microwave frequency range .