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Hydrolysis of 1,4‐cyclohexanedimethanol‐based copolyester
Author(s) -
Golovoy A.
Publication year - 1989
Publication title -
polymer engineering and science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.503
H-Index - 111
eISSN - 1548-2634
pISSN - 0032-3888
DOI - 10.1002/pen.760291605
Subject(s) - copolyester , relative humidity , terephthalic acid , materials science , ethylene glycol , hydrolysis , ethylene , analytical chemistry (journal) , polymer chemistry , water vapor , sorption , thermodynamics , organic chemistry , chemistry , composite material , polyester , physics , catalysis , adsorption
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 P H 2 Ois the water vapor partial pressure in kPa. For specimens 0.32‐cm thick, it took about 24 h to reach 0.9 C ∞ . The intrinsic viscosity ( IV ) was measured and used to calculate the relative change in molecular weight (M̄ w ) from the relationship IV ∝ (M̄ w ) 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 M̄ w was observed after 22 days at 95% relative humidity.