title: Biaxial deformations of rubber: a comparison between entanglement theory and elastic fluctuation theory.
abstract: The classical theory of rubber elasticity fails in the regime of large deformation. The underlying physical mechanism has been under debate for a long time. In this work, we test the recently proposed mechanism of thermal elastic fluctuations by Xing, Goldbart, and Radzihovsky (XGR) against the biaxial stress-strain data of three distinct polymer networks with very different network structures, synthesized by Urayama and Kawabata, respectively. We find that both the two-parameter version and the one-parameter version of the XGR theory provide a satisfactory description of the elasticity in whole deformation range. For comparison, we also fit the same sets of data using the slip-link model by Edwards and Vilgis with four parameters. The fitting qualities of two theories are found to be comparable.
authors.affiliation: Institute of Natural Science and Department of Physics, Shanghai Jiao Tong University, Shanghai 200240, China. xxing@sjtu.edu.cn
authors.forename: Xiangjun
authors.initials: X
authors.lastname: Xing