改性双氰胺衍生物环氧固化剂的制备及性能研究

分别采用环氧丙烷、环氧丙烷丁基醚(501)和环氧树脂(EP)对双氰胺(DICY)进行改性,制备了一系列新型的改性DICY衍生物作为EP固化剂,并对改性DICY/EP固化体系的性能进行了初步研究。结果表明:当反应温度为95～105℃、n(DICY)∶n(环氧丙烷)=1∶1.1和n(DICY)∶n(501)=1∶1.3时,环氧丙烷改性DICY(反应3.0 h左右)和501改性DICY(反应3.0～4.0 h)的收率较高;EP改性DICY的最佳反应条件为反应温度105℃左右、反应时间4.0 h左右和n(DICY)∶n(EP)=1∶1.3。环氧丙烷(或501)改性DICY在室温时具有一定的潜伏性,与EP的相容性得到明显改善,并且其固化体系的起始放热温度比DICY体系降低了近40℃(或30℃);EP改性DICY具有较好的潜伏性(与DICY相当),并且极易溶于EP中,但其固化体系的起始放热温度稍低于DICY体系。

Study on preparation and properties of modified dicyandiamide ramification as curing agent of epoxy resin

When propylene oxide,propylene oxide-butyl ether(501) and epoxy resin(EP) were used as modifier of dicyandiamide(DICY) respectively,so a series of new modified DICY ramification as curing agent of EP were prepared.The performances of modified DICY/EP curing systems were investigated.The results showed that the yields of DICY modified by propylene oxide(reaction time about 3.0 h) or by 501(reaction time between 3.0 h and 4.0 h) were higher when reaction temperature was 95-105℃,molar ratio of DICY to propylene oxide was 1:1.1, molar ratio of DICY to 501 was 1:1.3.The optimal reaction condition of DICY modified by EP was obtained when reaction temperature was 105℃about,reaction time was 4.0 h about,molar ratio of DICY to EP was 1:1.3.The DICY modified by propylene oxide(or 501) had definite latent at room temperature,and the compatibility between DICY modified by propylene oxide(or 501) and EP was improved,and the initial exothermic temperature of the curing systems with DICY modified by propylene oxide(or 501) as curing agent was 40℃(or 30℃) less than with DICY as curing agent.The DICY modified by EP had better latent(namely it was similar to DICY),and was easily dissolved in EP,but the initial exothermic temperature of the curing systems with DICY modified by EP as curing agent was slightly less than with DICY as curing agent.