Chemical Treatment of Epoxy Resins to: 1. Reduce Moisture Sensitivity and 2. Improve the Mechanical Properties.

摘要

Epoxy resin/graphite fiber composites absorb moisture which has a deleterious effect on composite mechanical properties. The moisture results from the electrostatic attraction between residual functional groups on the epoxy resin molecules and water, blocking the functional groups with various reactants decreases the epoxy resin equilibrium moisture absorption as much as 75%. Marked isocyanates incorporated into the resin prior to curing permits in situ blocking of the functional groups, reduces moisture absorption up to 65% without affecting the elastic modulus. The resin Tg is lowered, but the stress-strain properties are generally unaffected. (JES)