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Chemorheological changes in crosslinked epoxy resins subjected to large strains
Author(s) -
Katz Dov,
Buchman Alisa
Publication year - 1977
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.760170205
Subject(s) - epoxy , materials science , oxidizing agent , composite material , swelling , modulus , torsion (gastropod) , epoxide , logarithm , strain (injury) , organic chemistry , chemistry , mathematics , medicine , mathematical analysis , surgery , catalysis
Chemorheological changes in epoxy resins subjected to large strains while heated were observed earlier, but the subject was not treated quantitatively. This paper describes the investigation of an epoxy resin—Epon 826, of known chemical, structure, crosslinked with two different amines. By means of a simple calibrated apparatus, the epoxide samples were subjected to large strains in a non‐oxidizing atmosphere and in air. They were heated to different temperatures for various times; the results were compared with data obtained from unstrained samples kept in otherwise the same conditions. The results show a linear‐logarithmic relation between the torsion modulus, G (10) and the time of applied strain at a certain temperature and also a linear relation between G (10) , and 1/T°K, both above T (10) . The results obtained in swelling experiments support the data from 10 sec torsional modulus vs temperature measurements. An increase in the amount of solubles and in M c is observed on extending the time of heating. A clear difference in properties between the strained and unstrained samples, kept in otherwise the sane conditions, is observed and the contribution of the applied strain to chemorheology has been shown. Both systems of crosslinked Epon 826 showed the same general behavior, although the specific data were different.