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Elastomers with multimodal distributions of network chain lengths
Author(s) -
Mark J.E.
Publication year - 2003
Publication title -
macromolecular symposia
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.257
H-Index - 76
eISSN - 1521-3900
pISSN - 1022-1360
DOI - 10.1002/masy.200390002
Subject(s) - elastomer , materials science , extensibility , tearing , modulus , composite material , compression (physics) , shear modulus , stiffness , gaussian , polymer science , computer science , physics , quantum mechanics , operating system
The goal of primary interest in these investigations was the development of a novel method for preparing elastomeric networks having unusually good ultimate properties. The technique involves end linking mixtures of very short and relatively long functionally‐terminated chains to give bimodal networks. Such (unfilled) “bimodal” elastomers show very large increases in reduced stress or modulus at high elongations because of the very limited extensibility of the short chains present in the networks. This non‐Gaussian behavior also appears in compression or biaxial extension, shear, tearing, and cyclic fatigue tests. Non‐Gaussian theories taking into account this limited extensibility give a good account of the experimental results. Bimodal distributions also facilitate strain‐induced crystallization, and thus the reinforcement it provides. Suggestions are made for seeking additional advantages from multimodal distributions that are trimodal or higher.