Stress dependence of water diffusion in epoxy resin

✍ Scribed by A. A. Fahmy; J. C. Hurt

• Publisher: Society for Plastic Engineers
• Year: 1980
• Tongue: English
• Weight: 338 KB
• Volume: 1
• Category: Article
• ISSN: 0272-8397
• DOI: 10.1002/pc.750010205

✦ Synopsis

Abstract

The effect of stress on the diffusion of water in glassy polymers is analytically treated. Utilizing the free volume concept the effect of stress on the free volume fraction is established and in turn is related to the diffusion coefficient yielding the following formula: D~σ~ = D~o~e^(6 to 10)σ/G^ where D~σ~ and D~o~ are the diffusion coefficients in the presence and absence of stress respectively, G is the shear modulus, and σ is the stress. Experiments are described which demonstrate that in a bent epoxy bar, more water is picked up at the tension side than at the compression side. Theory and experiment are discussed and compared.