Bonding in urethane elastomers

Autor: L. B. Weisfeld, J. R. Little, W. E. Wolstenholme
Rok vydání: 1962
Předmět:
Zdroj: Journal of Polymer Science. 56:455-463
ISSN: 1542-6238
0022-3832
DOI: 10.1002/pol.1962.1205616417
Popis: Ordinary modulus–temperature physical test data at low deformations for unswollen gum elastomers has been partitioned into contributions from primary and secondary interchain linkages. The analysis is based upon the supposition that primary or covalent bonds conform to the statistical theory of rubberlike elasticity, while secondary interchain bonding adheres to Arrhenius Law. This treatment was applied to peroxide-cured millable elastomers, diamine-cured polyester diisocyanates, and several thermoplastic polyureaurethanes. Information resulted on the primary crosslink density, cure agent efficiency, activation energy for secondary bonding, and the relative contributions of respective bonding phenomena at various temperatures. These considerations afford a better understanding of the relationships between structure, composition and mechanical properties in polyurethane elastomers. Mechanisms are proposed relating the type of crosslink to its effect on secondary bonding, and the geometry of the spine on deviations from kinetic elastic theory at high extensions.
Databáze: OpenAIRE
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