改性VER的制备及其对PU/VER IPN的性能影响

采用不同的方法对乙烯基酯树脂(VER)中环氧丙烯酸酯(AAEP)进行羟基封闭,制备改性VER。采用红外光谱(IR)方法研究了封羟基试剂(乙酸酐、乙酰氯)、反应温度、投料比对AAEP中仲羟基的封闭效果,确定了最佳的工艺条件。采用未封羟基的VER(VER为质量比为2∶1的AAEP和甲基丙烯酸丁酯混合液)、封羟基的VER分别与自制PU在室温下同步互穿制备了PU/VER IPN和PU改/性VER IPN材料,并将改性前后IPN材料进行力学及动态热力学性能的比较,结果表明:由于改性VER中AAEP的仲羟基被封闭,PU和VER两网络间不存在化学交联,使IPN材料的拉伸强度比改性前降低,而断裂伸长率明显增加,拓宽了IPN的有效阻尼温域,提高了IPN材料的阻尼性能。

The preparation of modified VER and its influence on PU/VER IPN performance

The hydroxyl groups of epoxy acrylate(AAEP) in VER were sealed with different methods in order to obtain modified VER.IR was adopted to study the influence of the reagents used to seal the hydroxyl groups(acetic anhydride,acetyl chloride),the reaction temperature,the feed molar ratio on the sealing effect of hydroxyl groups and the optimal technical conditions were determined.The PU/VER IPN and PU/modified VER IPN were prepared by simultaneous interpenetrating of VER(mixture of AAEP and butyl methacrylate with the mass ratio of 2/1) or modified VER and synthesized PU in our laboratory.The mechanical properties and dynamic mechanical properties of PU/VER IPN and PU/modified VER IPN were compared.The results showed that compared to unmodified IPN,because the hydroxyl groups in VER were sealed and no chemical cross-linked structure existed between the two networks,the tensile strength of modified IPN decreased,while its break elongation increased.The effect damping temperature range of modified IPN was broadened and its damping performance was improved.