Anisotropic swelling of rubber: extension of the Flory theory

Fernandes, V. A.; De Focatiis, D. S. A.

Abstract

The anisotropy of the swelling of rubber is examined both theoretically and experimentally. The Flory theory is extended to account for anisotropic swelling, allowing the determination of the average molecular weight between cross-links for rubber with swelling anisotropy for the first time. In addition, specimens from five commercial rubbers manufactured using either compression-moulding or sheet-rolling processes are swollen in appropriate organic solvents. Their linear dimensions and mass are carefully recorded before swelling, in the swollen state, and after drying, to obtain three linear swelling ratios which can differ by up to 10% within each specimen. Compression-moulded rubbers are shown to be transversely isotropic after moulding, whereas rolled rubbers exhibit full anisotropy, with different swelling ratios in all three directions. None of the rubbers examined were found to be truly isotropic. The new anisotropic swelling theory is applied to the experimental data to determine the average molecular weight between cross-links, which is determined as up to 0.5% larger than the value obtained using the Flory isotropic swelling theory.

Citation

Fernandes, V. A., & De Focatiis, D. S. A. (2022). Anisotropic swelling of rubber: extension of the Flory theory. Journal of Rubber Research, https://doi.org/10.1007/s42464-022-00183-2

• Journal Article Type: Article
• Acceptance Date: Oct 17, 2022
• Online Publication Date: Nov 8, 2022
• Publication Date: Nov 8, 2022
• Deposit Date: Nov 15, 2022
• Publicly Available Date: Nov 15, 2022
• Journal: Journal of Rubber Research
• Print ISSN: 1511-1768
• Electronic ISSN: 2524-3993
• Publisher: Springer
• Peer Reviewed: Peer Reviewed
• DOI: https://doi.org/10.1007/s42464-022-00183-2
• Keywords: Organic Chemistry, Plant Science
• Public URL: https://nottingham-repository.worktribe.com/output/13465479
• Publisher URL: https://link.springer.com/article/10.1007/s42464-022-00183-2