Effect of Applied Stress, Thermal Environment and Water in Epoxy Resins.
Abstract
Because of their elevated physical properties, epoxy resins are widely used as matrices for high performance composites. However, due to moisture induced plasticization and formation of microcavities, high temperature and humidity tend to reduce their physical properties. A history dependent solubility model is generalized in accordance with the Dual Mode Sorption theory to account for effective water diffusion coefficients based on microcavitational damage brought about by temperature and moisture. Laboratory testing for weight changes in sorption-description experiments have been accomplished using a McBain quartz-spring microbalance placed in a temperature and humidity controlled cell. Equilibrium moisture absorption levels were represented both by linear and upward isotherms depending upon the humidity history. Analysis of sorption data, using a transport model in which part of the diffusing molecules are completely immobilized in the formed microcavities, revealed the damaging process to be in agreement with the diffusion coefficient depressions and solubility increases predicted by the model. A crazing criterion is qualitatively used to test the nature of the damaging process. (Author)
Document Details
- Document Type
- Technical Report
- Publication Date
- Nov 01, 1979
- Accession Number
- ADA086200
Entities
People
- A. Apicella
- E. Drioli
- L. Nicolais
Organizations
- University of Naples Federico II