摘要
为研究中温固化环氧树脂固化体系改善常见高温固化环氧树脂的应用受限及不足,笔者以双氰胺(DCD)为环氧树脂固化剂,2-甲基咪唑(2-MI)为促进剂,通过溶剂交换和熔融共混相结合的方法制备了环氧树脂/2-甲基咪唑/双氰胺的改性环氧树脂复合材料。试验通过添加不同质量分数的2-MI分析环氧树脂性能的变化。采用冲击、拉伸性能测试、热重分析(TGA)和扫描电镜(SEM)方法研究了复合材料的力学性能、热稳定性及断面形貌。结果表明,2-MI的加入可有效改善体系的拉伸和冲击强度,且加入质量分数为0.4%~0.5%时最佳,断裂伸长率显著提升,起到明显增强和增韧作用。扫描电镜显微镜分析结果表明,加入固化剂的环氧树脂复合材料界面黏合性更好,但2-MI的加入量对体系热稳定性无明显影响。
Most epoxy resins cure under high temperature, which limit their applications. An epoxy resin cured at medi-um temperature was developed in this study, and in this resin system, dicyandiamide （DCD） and 2-methyl imidazole （2-MI） were chosen as the curing agent and accelerant, respectively. The effect of the addition of 2-MI in the DCD! EP system on the physical and mechanical properties of the modified epoxy resin was investigated. The EP/2-MI/ DCD modified epoxy resin composites were prepared by a method combined of solvent exchanging and melt mixing. The mechanical properties of the resin composite were investigated by tensile, and impact test and thermal stability of the composites were studied by using thermogravimetric analysis （TGA）. The fractured surfaces of the cured samples were investigated by the scanning electron microscopy （SEM） to characterize its morphological structure. The results showed that the impact and tensile strength of the composites both increased with the 2-MI addition. The optimal a-mount of 2-MI in the epoxy adhesives was between 0.4 wt% and 0.5 wt%, at which the tensile strength reached the highest value of 72.54 MPa (2-MI addition was 0.4 wt%), and the maximum impact strength was up to 14.99 kJ/m2 (2-MI addition was 0.5 wt%). Meanwhile, the toughness of the dipping laminated plate also increased along with the addition of 2-MI. The results of the SEM analysis showed that the modified epoxy resin was more firm and compact, indicated that the properties of the modified epoxy resin was improved. However, the results of thermogravimetric a-nalysis showed that the addition of 2-MI had no significant effect on the thermal stability of the resin composite. The addition of 2-MI might form a three-dimensional network structfire in the epoxy resin macro-molecule when the bis-phenol-A epoxy resin cured, which thus gave the epoxy resin a stable structure with infusible and insoluble properties, as well as a considerable thermal stability and heat resistance.
作者
何星蔚
张金杰
王恒旭
傅深渊
庞久寅
王发鹏
HE Xingwei;ZHANG Jinjie;WANG Hengxu;FU Shenyuan;PANG Jiuyin;WANG Fapeng(Engineering College, Zhejiang A ＆ F University, Hangzhou 311300, China;Beihua University, Jilin 132000, Jilin, China)
出处
《林业工程学报》
北大核心
2018年第3期63-67,共5页
Journal of Forestry Engineering
基金
国家自然科学基金(31270589)
