木质素改性的酸酐固化环氧树脂体系研究

Study on lignin-modified acid anhydride cured epoxy resin system

利用非等温示差扫描量热法对酸酐固化的环氧树脂体系进行固化动力学研究,得到最优固化工艺为120℃/5 h+170℃/1 h。将木质素磺酸盐溶解在乙二醇中,随后加入环氧树脂、酸酐及促进剂共混得到木质素改性环氧体系。该体系在最优固化工艺下固化后,通过拉伸、冲击性能测试和扫描电镜研究了木质素和乙二醇协同作用下酸酐固化的环氧树脂体系的力学性能和形貌结构。结果表明,木质素磺酸盐在乙二醇中具有较好的溶解性。刚性木质素结构可与柔性乙二醇协同增强环氧树脂,与纯环氧体系相比,改性后环氧体系的拉伸强度、韧性和冲击强度分别提高了18.0%,53.3%和15.1%。

The curing kinetics of the anhydride-cured epoxy resin system was studied by non-isothermal differential scanning calorimetry, and the optimal curing process was obtained as 120 ℃/5 h +170 ℃/1 h. The lignin sulfonate was dissolved in ethylene glycol, and then the epoxy resin, acid anhydride and accelerator were added and blended to obtain a lignin-modified epoxy system.After the system was cured under the optimal curing process, the mechanical properties and morphology of the epoxy resin system cured by acid anhydride under the synergistic effect of lignin and ethylene glycol were studied by tensile property and impact property testings and scanning electron microscopy. The results showed that lignosulfonate had good solubility in ethylene glycol. The epoxy resin could synergistically reinforced by rigid lignin structure and soft ethylene glycol. Compared with pure epoxy system, the tensile strength,toughness and impact strength of modified epoxy system were increased by 18.0%, 53.3% and 15.1%, respectively.