Heat capacities were measured for three aromatic polysulphones : poly (1,4-phenylene sulphonyl), PAS; poly(oxy-l,4-phenylene-sulphonyl-l,4-phenylene), PPES; and poly[oxy-l,4-phenylene-sulphonyl-l,4- phenylene-oxy-l,4-phenylene-(1-methylidene)-l,4-phenylene], PBISP; from 150 to 620K using differential scanning calorimetry. These new data, along with the prior ATHAS (Laboratory for Advanced Thermal Analysis, University of Tennessee) recommended experimental heat capacities for three aliphatic polysulphones : poly ( 1-propene sulphone ), P 1PS ( 20- 300 K ) ; poly ( 1 -butene sulphone ), P1BS (100-300 K); poly(1-hexene sulphone), P1HS (20-300K), were fitted to an approximate frequency spectrum below their respective glass transition temperatures. The ATHAS computation scheme was used to compute the heat capacities that arise from these vibrations from 0.1 to 1000 K. The 01-temperature changed from 685 K for PIPS to 587 K for P1HS while for PPES and PBISP much higher values (799.5 K and 777.8 K) than the other phenylene polymers analysed at ATHAS, were obtained. Using these data and the smoothed experimental liquid heat capacities, the glass transition temperatures for PAS, PPES and PBISP were obtained at 492.6,497.4 and 458.2 K. The corresponding values for ACp were 18.1, 37.7 and 126.6 J K-t tool-1, respectively.
Посилання на статтю:
Heat capacities of aliphatic and aromatic polysulphones / Manika Varma-Nair, Yimin Jin and Bernhard Wunderlich // Polymer. – 1992. – Vol 33. – P. 5272-5281.