HEAT-CAPACITY AND THERMODYNAMIC FUNCTIONS OF POLY(THIO-1,4-PHENYLENE), POLY(OXY-1,4-BENZOYL), AND POLY(OXY-2,6-DIMETHYL-1,4-PHENYLENE) AT 0-325 K

The temperature dependence of isobaric heat capacity of poly(thio-1,4- phenylene), poly(oxy-1,4-benzoyl), and poly(oxy-2,6-dimethy1-1,4-pheny lene) was measured using a vacuum-coated adiabatic calorimeter in the range from 5-10 K to 325 K with an accuracy of ca. 0.2%. The correspon ding thermodynamic functions H-0(T) - H-0(O), S-0(T) S-0(O), G(0)(O)- H-0(O) were calculated for the range 0 - 325 K. The data of this work were compared with those reported in the literature for the temperatur e interval from 80 - 170 to 325 K. They were shown to agree satisfacto rily.