| Popis: |
The thermodielectric spectra of two series of amorphous polyole-fins were obtained from −180°C to above their glass transitions temperatures. Frequencies of 30 Hz, 100 Hz, 1kHz and 10 kHz were utilized to obtain “apparent” activation energies of both the glass (α) and glassy-state (β + γ) transitions and to correlate the loss maxima with published dynamic mechanical studies.1,2 These two series of amorphous polymers are represented by the formulae -[(CH 2 ) m − C(CH 3 ) 2 ]- n and -[(CH 2 ) m C(CH 3 ) (C 2 H 5 )]-n where m = 1, 2, and 3. These polymers are of fundamental importance to polymer science. A reason for their importance lies in the systematic in-chain variation of one — CH 2 — between consecutive members of each series since it is the structure and influence of the main chain per se which is central to polymeric behavior. The absence of polar forces, tacticity and crystallinity allows the results to be interpreted solely in terms of geometric effects. One reason for neglect of the series is that synthetic problems remain.1, 3 |
