环氧–复合稀释剂拉挤体系的制备及其性能研究

Preparation and Performance of Epoxy Resin-Composite Diluent System for Pultrusion

摘要: 以新戊二醇二缩水甘油醚(D-678)与聚丙二醇二缩水甘油醚(PPGDGE)为复合活性稀释剂，制备适配拉挤成型工艺的环氧树脂体系。通过差示扫描量热法(DSC)、旋转粘度测试、纤维浸润性观察、力学性能测试及动态力学分析(DMA)，系统表征体系固化行为、工艺特性、界面相容性、宏观力学性能与微观网络结构参数，揭示复合稀释剂协同调控机制。结果表明：复合稀释剂体系25℃粘度368 mPa∙s，80℃降至174 mPa∙s，纤维浸润时间 ≤ 62 s，满足拉挤快速浸渍要求；高温反应活性高，固化放热峰温154.59℃，适配连续高效生产；拉伸强度77.41 MPa、弯曲强度97.62 MPa，强度保持率优于单一稀释剂体系；DMA测试显示，复合体系储能模量、玻璃化转变温度(Tg)与交联密度介于两种单一稀释剂体系之间，微观交联网络更均衡，从分子层面证实协同增效机理。该体系兼顾低粘度、优浸润、高活性与高强度，可满足拉挤工艺与长期服役要求，工程应用前景良好。

Abstract: An epoxy resin system suitable for pultrusion molding was prepared using neopentyl glycol diglycidyl ether (D-678) and polypropylene glycol diglycidyl ether (PPGDGE) as composite reactive diluents. The curing behavior, process characteristics, interfacial compatibility, macroscopic mechanical properties and microstructure parameters were systematically characterized by differential scanning calorimetry (DSC), rotational viscosity test, fiber wettability observation, mechanical property test and dynamic mechanical analysis (DMA). The results show that the composite diluent system has a viscosity of 368 mPa∙s at 25˚C and decreases to 174 mPa∙s at 80˚C, with fiber wetting time ≤ 62 s, meeting the rapid impregnation requirements of pultrusion. It has high reactivity at high temperature with a curing exothermic peak temperature of 154.59˚C, suitable for continuous and efficient production. The tensile strength is 77.41 MPa and the flexural strength is 97.62 MPa, with higher strength retention than single diluent systems. DMA tests show that the storage modulus, glass transition temperature (Tg) and crosslinking density of the composite system are between the two single diluent systems, and the micro crosslinking network is more balanced, confirming the synergistic mechanism at the molecular level. This system integrates low viscosity, excellent wettability, high reactivity and high strength, which can meet the process and long-term service requirements of pultrusion, and has good engineering application prospects.