ISSN:
1022-1352
Keywords:
Chemistry
;
Polymer and Materials Science
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
,
Physics
Notes:
In adiabatic vacuum and dynamic calorimeters the temperature dependence of the heat capacity Cp0 of (R,R,R-4,8,12-trimethyl-1,5,9-trioxadodeca-2,6,10-trione a twelve-membered cyclic trilactone), biotechnological poly[(R)-3-hydroxybutyrate] and highly isotactic poly[(R)-3-hydroxybutyrate] was studied between 5 K and 500 K; temperatures and enthalpies of melting of the above mentioned substances were measured. In a calorimeter with a static bomb and an isothermal shield the energy of combustion of the same substances was measured. From the results the thermodynamic functions Cp0 (T), H0(T) - H0 (0), S0 (T), G0 (T) - H0 (0) were calculated in the range of 0 K to 500 K and thermochemical parameters ΔHcomb0, ΔHf0, ΔSf0, ΔGf0 were estimated at T = 298,15 K and standard pressure. The thermodynamic parameters of depolymerization of the biotechnological polymer to the 12-membered trilactone ΔHdepol0, ΔSdepol0 ΔGdepol0 and of the polymerization of the monomer formed in the highly isotactic poly[(R)-3-hydroxybutyrate] ΔHpol0, ΔSpol0, ΔGpol0 were calculated for 0 K to 500 K.
Additional Material:
4 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/macp.1996.021970431
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