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Birefringence in an epoxy polymer during stress‐relaxation and recovery
Author(s) -
Srivastava A. K.,
White J. R.
Publication year - 1984
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.1984.070290419
Subject(s) - birefringence , stress relaxation , relaxation (psychology) , materials science , epoxy , stress (linguistics) , composite material , residual stress , polymer , optics , creep , medicine , physics , linguistics , philosophy
Measurements of birefringence during stress–relaxation and recovery have been recorded for examples of an epoxy resin cured at three different temperatures. Birefringence remained constant during stress–relaxation even after prolonged testing during which the stress fell considerably. The stress sensitivity was found to be the same on both loading and unloading so that, immediately after unloading, the birefringence was different to that prior to the stress–relaxation test. This residual change began to decay after a prolonged period free from applied stress. No significant differences were noted in the birefringence measurements made on samples cured at different temperatures, but, when the stress–relaxation data were analyzed by the procedure of Kubát and Rigdahl, marked differences appeared.