端氨基树枝状大分子PAMAM/环氧树脂 体系固化物的性能

以端氨基树枝状大分子PAMAM作为环氧树脂固化剂, 通过拉伸试验、 冲击试验、 DSC、 TGA研究了配比和固化温度对PAMAM与环氧树脂E-44的固化物性能的影响。 结果表明, 最佳固化温度为140℃, 但随着固化温度升高, 配比的影响表现出不同的规律: 80℃固化时, 最佳配比为0.47, 此时拉伸强度和冲击强度最佳, 玻璃化转变温度最高, 交联密度最大; 而在80℃以上固化时, 最佳配比逐渐向低配比方向移动, 140℃固化时, 最佳配比为0.28, 此时拉伸强度和冲击强度最佳, 玻璃化转变温度最高, 交联密度最大。固化物的密度和体积收缩率都是配比为0.47时最大, 而热稳定性都是配比为0.28时最佳。利用滴定法测定了固化物的固化度, 结果表明, 随着固化温度的升高, 低配比体系的固化度迅速提高并接近化学计量点配比体系的固化度。

Properties of cured compound of amine-terminated dendrimer PAMAM/epoxy resin system

Amine-terminated dendrimer PAMAM was used as an agent in the epoxy resin system, and the influence of the ratio and curing temperature on the properties of cured compounds of PAMAM and epoxy resin was studied by tensile test, impact test, DSC and TGA. The results show that the optimum curing temperature is 140℃, and the influence of the ratio of PAMAM to epoxy resin is different as the curing temperature changes: the optimum ratio is 0.47 (mass ratio of PAMAM to epoxy resin) cured at 80℃, where the optimum mechanical property, the highest glass translation temperature and crosslink density can be obtained. The optimum ratio shifts to a lower ratio as the curing temperature increases: the optimum ratio is 0.28 cured at 140℃, where the optimum mechanical property, the highest glass translation temperature and crosslink density can be obtained. However, the density of the cured compounds and the volume shrinkage reach the maximum when the ratio is 0.47, and the thermal stability is the best when the ratio is 0.28. The cure degree was determined by titration, the result showing that the cure degree of the lower ratio system rapidly soars and approaches the cure degree of the stoichiometric point system as the curing temperature increases.