一种高韧性耐湿性环氧树脂的合成及其性能研究

利用β-甲基环氧氯丙烷与双酚A在氢氧化钠的存在下合成了一种新的甲代双酚A型缩水甘油醚环氧树脂(BPA-MECH EP)预聚物,并通过FT-IR、1H NMR、GPC等手段对产物结构进行了表征。用盐酸-丙酮滴定法测定其环氧值为0.43 mol/100 g。用DDM作固化剂,利用DSC对其添加量为树脂质量的20%时体系的固化反应动力学以及最佳固化工艺条件进行了探讨。实验结果表明:BPA-MECH/DDM固化体系的反应级数n为1.30;表观活化能为15.37 kJ/mol;最佳固化工艺条件为:120℃/1 h→140℃/1 h→175℃/3 h→200℃/1 h逐步阶段升温固化。与E-44的DDM固化物进行了性能比较,结果表明:BPA-MECH与E-44固化产物的热变形温度无显著差别,但吸水率降低了47.6%,弯曲强度和弯曲模量分别提高了10.5%和7.8%,冲击强度上升了129.4%,拉伸强度、弹性模量以及断裂伸长率都有不同程度的提高,最大增幅分别为27.6%、25.9%和12.9%。研究结果表明,甲代双酚A型缩水甘油醚环氧树脂是一种性能优良的环氧树脂预聚物。

Study on Synthesis and Properties of a High Toughness and Water-resistant Epoxy Resin

A novel pre-polymer of bisphenol epoxy resin(BPA-MECH) was synthesized from the reaction of β-methyl-epichlorohydrin(MECH) with bisphenol A(BPA) and its structure was characterized by 1H-NMR,FT-IR and GPC.The result of titration showed that the epoxy value of BPA-MECH EP was 0.43 mol / 100 g.The curing behavior of the BPA-MECH / 4,4’-diamino-diphenylmethane(DDM) epoxy system was studied by means of differential scanning calorimeter(DSC).The DSC data declared that the value of the activation energy(Ea) and the curing reaction order(n) is 15.37 kJ / mol and 1.3,respectively,and the optimal curing process was as following: 120℃ / 1 h→140℃ / 1 h→175℃ / 3 h→200℃ / 1 h.Compared to the properties of the DDM / E44 composites,the impact strength,bending strength,bending modulus,tensile strength,flexural modulus and elongation at breaking of DDM / BPA-MECH composites increased by 129.4%,10.5%,7.8%,27.6%,25.9% and 12.9%,respectively,while the ratio of water absorption decreased by 47.6%.However,there is no significant change of heat resistance temperature.All data demonstrated that BPA-MECH was an epoxy pre polymer with excellent properties.