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Birefringence of injection‐molded glassy polymers during relaxation and recovery
Author(s) -
Qayyum M. M.,
White J. R.
Publication year - 1983
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.1983.070280617
Subject(s) - polymer , birefringence , polarizability , materials science , relaxation (psychology) , polyamide , polymer chemistry , poly ethylene , side chain , polymer science , chemical physics , composite material , molecule , ethylene , organic chemistry , optics , chemistry , physics , psychology , social psychology , catalysis
Birefringence measurements have been made on six glassy polymers during stress–relaxation and recovery experiments at temperatures below T g . Of the six polymers tested only one pair, poly(ethylene terephthalate) and a glassy polyamide (“Trogamid”), show a strong mutual resemblance in the behavior of birefringence under these conditions. The results are discussed with reference to molecular structure, and, although detailed interpretations are not offered, it is observed that the behavior is less complex for polymers which possess their most polarizable groups in the main chain or attached rigidly to it than for those polymers having polarizable side groups with relaxations which do not involve the main chain. All six polymers have been tested in injection‐molded form, and the possible consequences of this are considered. The major differences observed to occur between the different materials do not appear to be related to processing, however, and some results obtained using specimens prepared in other ways are also presented to illustrate this.