Strain-Induced Crystallization in Rubbers
As it is well known, crosslinked samples of stereoregular polymers are able to crystallize at temperatures higher than T m o , i.e., the ideal melting point, if suitably deformed. Conformational entropy decrease of the molten chains, induced by deformation, is responsible for the effect1, which is especially important in improving the ultimate properties of the material. It is the purpose of the present study i) to clarify the critical aspects of melting in strained rubberlike samples; ii) to discuss the favourable effect induced by relatively small values of the specific melting entropy upon the rubber’s technical performance; iii) to point out the relationship between conformational disorder in polymer crystallites and the small entropic value referred to above, discussing few examples of practical relevance2.
KeywordsNatural Rubber Statistical Segment Ultimate Property Rubberlike Material Stretch Direction
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