摘要：

用不同量的端巯基液体聚硫橡胶（PSR）对酚醛环氧树脂（F-51）进行改性，合成 F-51/PSR预聚物，并用 3种不同的固化剂（聚酰胺固化剂 PA650、环氧酚醛胺固化剂 T-31、腰果壳油改性胺固化剂 NX-5454）分别对其进行固化。用红外光谱（FT-IR）对 F-51/PSR预聚物的分子结构进行了表征。通过对改性环氧固化物拉伸性能的测试和用扫描电子显微镜（SEM）对固化物断面形貌的分析，评价了该固化物的增韧效果并分析了其增韧机理。此外还通过差示扫描量热仪（DSC）和热重（TGA）对涂膜的固化行为与热稳定性能进行了研究。结果表明 PAR可以有效增韧 F-51树脂，采用NX-5454为固化剂，当 M（PSR）∶M（F-51）＝0.2时，涂膜柔韧性和干燥速度得到了最有效提高，断裂伸长率从 6.42%增长到 18.25%，室温下涂膜 1.5 h内表干，4.5 h内实干，达到了快速固化的要求。

关键词: 酚醛环氧树脂, 液体聚硫橡胶, 柔韧性, 快干, 防腐蚀

Abstract:

A phenolic epoxy resin( F-51)was modified with different dosage of thiol-terminated liquid polysulfide rubber (PSR ) to form prepolymers (F-51/PSR). The synthesized prepolymers were cured with three different curing agents, e. g, polyamide curing agent PA650, epoxy phenolic aldehyde amine curing agent T-31 and cashew shell oil modified amine NX-5454. The structure of the synthesized prepolymers was characterized by FT-IR. By testing the tensile properties and analyzing the section morphology of the cured epoxy resin by SEM, the toughening effects were evaluated and the toughening mechanism was analyzed. Besides, the curing process and the thermal stability were respectively investigated by differential seanning calorimetry (DSC)and thermogravimetric analysis( TGA). Results showed that when the mass ratio of PSR and F-51 was 20%, the film got the optimal toughness and curing speed, e.g., the elongational break increased from 6.42% to 18. 25%, the dust-free time and hard drying time at room temperature was 1. 5 h and 4. 5 h res pectively, which met the requirement of fast drying process.

Key words: phenolic epoxy resin, liquid polysulfide rubber, toughness, fast drying, anticorrosion