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Dynamic mechanical analysis of polymers in the liquid state: Use of a perforated shim stock support
Author(s) -
Keinath Steven E.,
Boyer Raymond F.
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.1983.070280622
Subject(s) - materials science , brittleness , polymer , shim (computing) , composite material , brass , dynamic mechanical analysis , coating , medicine , copper , erectile dysfunction , metallurgy
This report summarizes some initial results on the use of a perforated brass shim stock support to extend the useful range of dynamic mechanical testing well over 100 degrees above the traditional limiting polymer softening points of T g or T m . Weak secondary relaxations were observed above T g in both polyisobutylene (PIB) and polystyrene (PS) homopolymer, copolymer, and blend systems and above T m in gutta percha ( trans ‐polyisoprene). The DuPont 981 Dynamic Mechanical Analyzer (DMA)–990 Thermal Analyzer system was used to characterize these weak liquid state processes. The DMA instrument deforms the specimen in flexure, thus minimizing the shear component present in some other techniques. Specimen‐coating weights are typically in the range 20–40 mg. The perforations are particularly useful for polymers having low inherent adhesion to metals or systems which are very brittle in the glassy state, e.g., low MW PS's and many methacrylates.