Induced Anisotropy of Thermal Expansivity Under Large Deformations
The induced anisotropic behavior of highly deformed polymer solids, which were initially isotropic, can result from orienting the links of the polymer chain in the direction of deformation. The degree of anisotropy may depend on the monomer structure, but it depends mostly on the degree of deformation and thus, orientation. In the case of thermal expansion it may be considered that the thermal expansion of polymer solid is due to the increased separation of neighborhood polymer chains. In the undeformed state, the large molecule is randomly coiled and orientation of the segment is averaged out, hence the thermal expansivity will be isotropic. In the deformed state, however, this will no longer be true, but will depend on the average deformation, i.e., the orientation along a given direction.
KeywordsLarge Deformation Linear Expansivity Stretch Ratio Anisotropic Behavior Thermal Expan
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- (1).L.R. G. Treloar, “The Physics of Rubber Elasticity,” 2nd ed., Oxford University Press, Oxford, 1967, Chap. VI.Google Scholar