GLASS TRANSITION TEMPERATURE-LESS(TG-LESS) EPOXY RESIN AS A MATRIX OF HIGH HEAT RESISTANT COMPOSITE

摘要

A T{sub}g-less epoxy resin was easily obtained by curing with a salt of alkaline metal and carboxylic acid. In this system the storage modulus did not drop and maintained a high level as if it were in a glassy state even at an elevated temperature such as 300°C. Investigation of the curing process for the epoxy resin mixture with ionomer including potassium carboxylates revealed that the curing reaction was initiated from the nucleophilic addition of -COO- to the epoxy group to form an ester linkage and that the chain propagation subsequently occurred by anionic ring opening polymerization of the epoxy group to form an ether linkage. On the basis of the results, the mechanism of 'T{sub}g-disappearing phenomenon' was proposed. Further, the heat resistance of the composite consisting of the T{sub}g-less epoxy resin and fiber fabrics was also discussed.