Abstract
Naphthalene-based epoxy resins were synthesized through epoxydation of polyhydroxy compounds obtained by the condensation reaction of naphthols or dihydroxynaphthalenes with condensing agents, i.e. formaldehyde, P-xylylene glycol and 2, 6-dimethylol-p-cresol, and the relation between the structure and properties of their cured products with phenol novolac was studied.
The following results were obtained. The introduction of naphthalene nuclear into the resin structure was an effective way to decrease water absorption without losing heat resistance. The cured products from naphthalene-based epoxy resins gave smaller values in the linear thermal expansion coefficient than those from phenyl-ring epoxy resins. However, the linear expansion coefficient from the naphthalene-base cured resins reached almost the same value as that of phenol novolac-base resins, as a result of increasing crosslinking density in a glassy state near Tg above 200°C
