双酚A二氰酸酯树脂的固化特性研究

STUDY ON CURE CHARACTERISTICS OF DICYANATE OF BISPHENOL A RESIN

采用二步法合成双酚A二氰酸酯(BCE),由氰化钠和液溴反应合成溴化氰,溴化氰与双酚A在三乙胺的催化下合成BCE,产率在85%以上。运用红外光谱(IR)和差热分析(DTA)等手段对合成BCE树脂进行了表征,研究了提纯前后BCE树脂的固化反应特性,并探讨了金属催化剂的催化作用。结果表明,合成BCE的纯度对氰酸酯树脂的固化反应特性和固化物性能有很大影响。提纯将降低BCE树脂中的双酚A等杂质的含量,提高固化反应温度,提高树脂固化物耐热性。环烷酸钴对BCE树脂固化有明显的催化作用,固化反应放热峰起始温度Ti由207 2℃降低到167 8℃,凝胶化时间大大降低。

The Dicyanate of bisphenol A(BCE) was synthesized using the method of two steps,by reacting of NaCN with Br_2 to produce BrCN and then by reacting of BrCN with bisphenol A to synthesize BCE at the presence of catalyst of triethylamine and the yield was more than 85%.The structure and cure reaction characteristics of the synthetic dicyanate of bisphenol A(BCE) resin and the purified BCE were studied by using infrared spectroscopy(IR),differential thermal analysis (DTA) and gel time test.The suitable cure and postcure cycle of the resin was thus determined and the properties of the cured resin were evaluated.Metal cobalt naphthalate was chosen to catalyze the cure reaction of BCE resin in the paper.The results showed that the purified BCE had better properties than the unpurified and the purity of the synthesized BCE was a key factor influencing on the curing characteristics and properties of cyanate resin.The purified BCE resin had lower content of impurity such as residual bisphenol A than the unpurified,and thus leads to higher cure reaction temperature and better heat resistant properties of the resin cast.The addition of a little amount of the catalyst cobalt naphthalate (500 μg/g) could obviously accelerate the cure reaction of the resin for the onset cure temperature T_i to decrease from 207.2 ℃ to167.8 ℃.