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Short‐term and long‐term performance of thermosets exposed to water at elevated temperatures
Author(s) -
Römhild S.,
Bergman G.,
Hedenqvist M. S.
Publication year - 2009
Publication title -
journal of applied polymer science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.575
H-Index - 166
eISSN - 1097-4628
pISSN - 0021-8995
DOI - 10.1002/app.31548
Subject(s) - thermosetting polymer , vinyl ester , styrene , sorption , materials science , monomer , polymer , chemical engineering , polymer chemistry , chemistry , copolymer , composite material , organic chemistry , adsorption , engineering
Abstract The water‐transport, mechanical, and chemical‐structure changes in various vinyl ester, novolac, and urethane‐modified vinyl ester thermosets exposed to water at 50 to 95°C for times up to 1000 days have been studied within the framework of a larger study of osmotic blistering in fiber reinforced plastics (FRP) process components. The water sorption saturation concentration did not reach a steady‐state value but gradually increased in many cases upon long‐term exposure. The diffusion coefficient was not significantly affected. Infrared spectroscopy and gas chromatography‐mass spectrometry indicated that the net mass loss from the thermosets on immersion in water was due to the leaching of non‐reacted styrene, monomer, and additives. It is suggested that this, together with polymer relaxation processes (as measured on specimens under tension in water at 80°C), is the primary reason for the time‐dependent increase in the water saturation concentration. Infrared spectroscopy indicated that, even at the highest temperatures, hydrolysis of the polymer ester groups was small. Correlations were found between the styrene content in the uncured thermosets, the estimated solubility parameters, and the sorption and diffusion coefficients. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2010