The role of dielectric and dynamic mechanical techniques in the process monitoring and environmental resistance control of polymeric matrixes for composites.

The role of dynamic mech. and dielec. spectroscopy in the process monitoring and environmental resistance control of thermoplastic and thermoset polymeric matrixes for composites was analyzed. Morphol. modification occurring in PEEK during crystn., the chemorheol. behavior of an unsatd. thermosetting polyester, and the hydrothermal stability of epoxy and polyurethane based composites was investigated. An Avrami approach was adopted in order to interpret the dual-mode cold crystn. of the amorphous PEEK based on dielec., DSC and dynamic mech. analyses. The correlation between dielec. measurements, viscosity and degree of cure during the polymn. of a thermoset was discussed. Finally, the hygrothermal stability of epoxy and polyurethane based composites was analyzed in terms of dielec. modifications.