ISSN:
0032-3888
Keywords:
Chemistry
;
Chemical Engineering
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
,
Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
,
Physics
Notes:
The solid state hydrolysis of a copolyester based on a mixture of 1,4-cyclohexanedimethanol and ethylene glycol condensed with terephthalic acid was studied at 100°C and 57 to 96 kPa water vapor partial pressure (55% to 95% relative humidity). The equilibrium water sorption in weight percent (C∞) was found to be \documentclass{article}\pagestyle{empty}\begin{document}$$ C_\infty = 1.45 \times \,10^{ - 5} (P_{H_2 O} )^{1.2} $$\end{document} where PH2O is the water vapor partial pressure in kPa. For specimens 0.32-cm thick, it took about 24 h to reach 0.9C∞. The intrinsic viscosity (IV) was measured and used to calculate the relative change in molecular weight (M̄w) from the relationship IV ∝ (M̄w)0.7. The decrease in molecular weight was linear with time, and the rate of decrease was found to be proportional to C∞; the empirical correlation is \documentclass{article}\pagestyle{empty}\begin{document}$$ k = 0.026 \times C_\infty $$\end{document} where the rate constant, k, is in day-1. A decrease of 50% in M̄w was observed after 22 days at 95% relative humidity.
Additional Material:
5 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/pen.760291605
