脲促进双氰胺固化多官能环氧树脂性能的研究

Study on Properties of Urea Promoted Dicyandiamide Cured Multifunctional Epoxy Resin

在萘环/缩水甘油胺环氧树脂(质量比约1∶7.85)存在的复合物中,利用双氰胺(DICY)为固化剂,不同取代脲为固化促进剂,通过差示扫描量热仪(DSC)对比了其反应活性,热机械分析仪(TMA)对比了其玻璃化转变温度和线膨胀系数,热重分析仪(TG)对比了热失重,最后测试了拉伸剪切强度。结果表明,脲单独作为固化促进剂的双氰胺体系,当同时含缩水甘油醚和缩水甘油胺的多官能环氧树脂为主体树脂时,其DSC具有双峰表明环氧基的活性差异较大,更高的后固化温度有利于提高其耐热性能和拉伸剪切强度;芳香族脲(UR200、UR300、UR500、U-52M)比脂环族脲(U-35M)具有更加优异的耐热性能;对于改善复合物的耐高温黏接性能来说,UR300是最好的,其次是U-52M。

In the system of naphthalene ring/glycidyl amine type epoxy resin(mass ratio was about 1∶7.85),dicyandiamide(DICY)was used as curing agent and different substituted ureas were used as accelerators for curing.The reaction activity was compared by differential scanning calorimetry(DSC),the glass transition temperature and linear expansion coefficient were compared by thermal mechanical analyzer(TMA),the thermal weight loss was compared by thermogravimetric analyzer(TG),and the tensile shear strength was tested at last.The results show that for the multi-functional epoxy resin system with glycidyl ether and glycidyl amine as the main resin, the DSC of the dicyandiamide system cured by urea alone as an accelerator has double peaks, indicating that the activity of the epoxy group varies greatly, and higher post curing temperature is conducive to improve its heat resistance and tensile shear strength.Aromatic urea UR200/UR300/UR500/U-52M has better heat resistance than alicyclic urea U-35M.For improving the high temperature resistance of the composite, UR300 is the best, followed by U-52M.