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The thermal properties of poly(pivalolactone)
Author(s) -
Grebowicz Janusz,
VarmaNair Manika,
Wunderlich Bernhard
Publication year - 1992
Publication title -
polymers for advanced technologies
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.61
H-Index - 90
eISSN - 1099-1581
pISSN - 1042-7147
DOI - 10.1002/pat.1992.220030202
Subject(s) - heat capacity , materials science , amorphous solid , thermodynamics , glass transition , enthalpy , crystallinity , polyester , analytical chemistry (journal) , polymer , crystallography , physics , organic chemistry , composite material , chemistry
Quantitative thermal analysis was carried out for poly‐(pivalolactone) (PPVL), including heat capacity determinations from 140 to 550 K. The experimental C p below the glass transition temperature was fitted to an approximate vibrational spectrum and the ATHAS computation scheme was used to compute the “vibration only” heat capacities from 0.1 to 1000 K. The liquid C p was derived from an empirical addition scheme and found to agree with the experimental C p with an RMS of ±2.8% from 240 K to 550 K. A glass transition, T g , could be detected at 260 K, and the change in heat capacity for 100% amorphous PPVL was calculated to be 38.8 J/(K mol). Above T g , semicrystalline samples seem to show a rigid amorphous fraction that does not contribute to the increase in heat capacity at T g . Using the ATHAS recommended heat capacities, the various thermodynamic functions (enthalpy, entropy, and Gibbs function) were derived. The residual entropy at 0 K for the amorphous PPVL was calculated to be 5.2 J/(K mol) per mobile bead, and was comparable to that obtained for a series of linear, aliphatic polyesters analyzed earlier.