端氨基聚硫橡胶增韧改性环氧树脂

Epoxy Resin Toughened by Amino-Terminated Polysulfide Rubber

对聚硫橡胶进行封端改性,将氨基引入聚硫橡胶中以提升其活泼氢的含量。将不同配比的端氨基聚硫橡胶与环氧树脂混合反应,得到改性环氧树脂。用傅里叶变换红外光谱对改性环氧树脂进行结构分析;用动态力学热分析仪测定改性环氧树脂的动态力学性能;用拉力机、硬度计等对改性环氧树脂的拉伸强度、断裂伸长率及硬度进行测定,记录改性环氧树脂固化前后的体积变化得到收缩率。研究结果表明成功将氨基引入聚硫橡胶,端氨基聚硫橡胶中的活泼氢与环氧树脂反应,使环氧基开环,形成聚硫橡胶改性环氧树脂,聚硫橡胶作为软段,起增韧作用。固化体系中,随着活泼氢与环氧基摩尔比不断增加,从0.3逐渐变化到1.0时,固化物交联度增加,作为柔性链段的聚硫橡胶含量增多,断裂伸长率升高,由5%逐渐增加到17%,与之作为硬段的阴离子聚合环氧树脂组分不断减少,固化物的拉伸强度由16.8MPa逐渐降低至5.2MPa,邵氏A硬度由99下降至84。

The polysulfide rubber was terminal- modified by amino, which was introduced into polysulfide rubber to enhance its active hydrogen content. The modified epoxy resin was obtained by mixing different ratios of amino terminated polysulfide rubber with epoxy resin. The structure of the modified epoxy resin was analyzed by Fourier transform infrared spectroscopy. Dynamic mechanical properties of the modified epoxy resin were measured by dynamic thermal mechanical analyzer. The tensile strength, breaking elongation and hardness of the modified epoxy resin were measured by tension machine and hardness tester. The volume of the cured epoxy resin before and after curing was recorded to get the contraction rate. The results show that the amino is introduced into the polysulfide rubber and the active hydrogen in the amino terminated polysulfide rubber reacts with the epoxy resin. The ring of epoxy group is opened, the polysulfide rubber modified epoxy resin is formed, and the polysulfide rubber as soft segment play a toughening effect. In the curing system, the degree of crosslinking increases with the increase of mole ratio of active hydrogen and epoxy from 0.3 to 1.0. The content of polysulfide rubber as flexible segment increases, the elongation at break increases gradually from 5% to 17%, and the component of anionic polymerized epoxy resin as hard segment decreases. The tensile strength of cured product decreases gradually from 16.8 MPa to 5.2 MPa, and the hardness of Shore A decreases from 99 to 84.