ISSN:
0021-8995
Keywords:
Chemistry
;
Polymer and Materials Science
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
,
Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
,
Physics
Notes:
The stress-strain properties of natural rubber and synthetic cis-polyisoprene vulcanizates have been investigated over a large range of extensions. The results are in qualitative agreement with those of Mullins, in that the upturn of a Mooney-Rivlin plot is ascribed to finite extensibility effects. It is further found that the stress-strain curves can be adequately described by a modification of existing non-Gaussian theory. Analysis of the curves shows significant finite extensibility effects even at extensions well below the upturn. Thus, division of stress-strain curves into Gaussian and non-Gaussian regions is to be avoided. Values for n, the number of statistical segments between crosslinks, were calculated using the proposed treatment. The values of n found were relatively unaffected by temperature. Further, the molecular weight of a statistical segment was found to be about the same for synthetic cis-polyisoprene as for natural rubber despite differences in the crystallization behavior. Crystallization effects are therefore thought to be of little importance in determining the position of the upturn. The equivalent statistical segment was found to be 4.3 isoprene units for natural rubber and cis-polyisoprene.
Additional Material:
3 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/app.1964.070080201
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