不同长度脂肪链含萘环结构环氧树脂对NC-3000型环氧树脂的改性研究

为了研究不同脂肪链长度的环氧树脂对联苯苯酚环氧树脂/苯酚-亚联苯基固化剂(NC-3000/GPH-65)环氧体系的影响,合成了两种含萘环结构的具有不同长度脂肪链的环氧树脂R1和R2,通过核磁共振氢谱(1 HNMR)和元素分析(EA)对其结构进行了表征。将R1和R2以1%、3%、5%、7%(质量分数)的添加量分别加入NC-3000/GPH-65固化体系中制备固化物。通过示差扫描量热(DSC)和凝胶化时间测试研究R1和R2对NC-3000/GPH-65固化体系固化行为的影响,对改性固化物进行了热重分析(TGA)、弯曲强度测试、拉伸强度测试、吸水性和玻璃化转变温度(Tg)测试。结果表明,具有长链结构的R1对固化反应有延缓作用,而R2对固化反应有促进作用。随着R1和R2添加量的增加,改性固化物的力学性能、耐水性、Tg和耐热性都得到了一定程度的提高,通过SEM对固化物断面进行分析发现,固化物的断裂形式由脆性断裂变成韧性断裂。与短链结构的R2相比,长链结构的R1能够使固化物的力学性能、Tg和吸水率得到更大程度的提升,而其耐热性有一定程度的降低。

The Modification Effect on NC-3000 Resin of Epoxy Resins Containing Naphthalene Unit and Aliphatic Chains with Different Length

In order to understand the effect of the chain length variation of the initial resin on curing kinetics and the final properties of the cured products,two resins,R1 and R2,both contained naphthalene units and aliphatic chains with different length were synthesized and characterized by hydrogen nuclear magnetic resonance (1 H-NMR) and elemental analysis (EA).A series of composites were prepared by adding 1%,3%,5%,7% (mass fraction)R1 and R2 into NC-3000/GPH-65 curing system.The influence of the curing behavior R1 and R2 on NC-3000/GPH-65 curing system were investigated by differential scanning calorimetry (DSC)and gel time test study.The thermogravi-metric analysis (TGA),tensile strength,flexural strength,water absorption and lass transition temperature (Tg )of modified composite were investigated.The results showed that R1 (with long chain)could prolong while R2 (with short chain)could accelerate the curing process of NC-3000/GPH-65 system.Compared with pure NC-3000/GPH-65 system,the mechanical properties,moisture resistance,Tg and heat resistance of composites increased with the in-crease of the R1 and R2 content.The fracture surfaces morphology of the composites changed from brittle fracture to ductile fracture by scanning electron microscopy (SEM)observation.Compared with the short chain structure of the R2,the resin R1 with long chain structure improved the mechanical properties,Tg and moisture resistance of the cured composites while reduced the heat resistance to a certain degree.