Abstract
Three kinds of new epoxy resins, containing 4, 4'-biphenylene or 2, 6-naphthylene units, were synthesized. 4, 4'-Bis [2- (4-hydroxyphenyl) -2-propyl] biphenyl was prepared by the reaction of 4, 4'-bis (2-hydroxy-2-propyl) biphenyl and phenol. The phenol was hardly soluble in aq. NaOH solution. So 4, 4'- bis {2- [4- (2, 3- epoxypropoxy) phenyl] -2- propyl} biphenyl (Epoxy I) was prepared in two step reactions ; the reaction of the bisphenol with epichlorohydrin using a phase transfer catalyst, tetrabutylammonium bromide, at a reflux temperature in the absence of alkali, followed by epoxidation with aq. NaOH solution at a lower temperature (below 15°C). 4, 4'-Bis {2- [3, 5-dimethyl-4- (2, 3-epoxypropoxy) phenyl] -2-propyl} biphenyl (Epoxy II) was also prepared in a similar way. 2, 6-Bis {2- [3, 5-dimethyl-4- (2, 3- epoxypropoxy) phenyl] -2-propyl}naphthalene (Epoxy III) was prepared from 2, 6-bis [2- (3, 5- dimethyl-4-hydroxyphenyl) -2-propyl] naphthalene. The differential thermal analysis indicates that the curing reactivity of Epoxy I with p, p'-diaminodiphenyl sulfone is similar to that of diglycidyl ether of bisphenol A (DGEBA). The curing reactiuity is lower in Epoxy II and III. Tg's of the cured resins for Epoxy I, Epoxy II, Epoxy III, and DGEBA were observed at 155,191,188 and 183t, respectively. Physical properties for cured Epoxy I -III/ DGEBA blend resins (1 : 1 wt ratio) were examined. Water absorption of the cured epoxy resins decreased by introducing both methyl and biphenyl as well as naphthalene units.
