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A new mechanism for increasing tear strength and cut‐growth resistance of elastomers
Author(s) -
Stewart Charles W.
Publication year - 1993
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.1993.070480506
Subject(s) - tear resistance , elastomer , materials science , ultimate tensile strength , composite material , yield (engineering) , tension (geology) , mechanism (biology) , physics , quantum mechanics
A new mechanism is presented for increasing the tear strength of noncrystallizing elastomers over a broad temperature range. It is shown that the incorporation, into elastomers, of a plastic filler with the proper yield strength can substantially increase tear strength by decreasing the excess stress that develops at the tip of a sharp cut in an elastomer strip under tension. To be effective at low aspect (length/diameter) ratio, the yield strength of the plastic must be of the same order of magnitude as the tensile strength of the elastomer to which it is added. The analysis is strictly valid only for very small deformations, where crack‐tip blunting can be ignored, and for an applied stress sufficiently low that the plasticyielding zone is very small relative to the crack length. It provides a useful model, at least, for the development of a new mechanism for increasing the tear strength of fluoroelastomers at sufficiently high temperatures, which is of significant practical importance. Examples of the use of a new fluoroplastic micropowder to provide over a fourfold increase in tear strength of several fluoroelastomers at high temperatures are given. © 1993 John Wiley & Sons, Inc.