环氧丁羟/蒙脱土增韧改性环氧树脂包覆层的制备及性能研究

Preparation and Properties of Epoxy Resin Coating Layer Modified by Hydroxyl-terminated Epoxidized Polybutadiene/Montmorillonite

为了对环氧树脂(EP)包覆层进行增韧改性,用环氧丁羟(EHTPB)剥离有机蒙脱土(OMMT),制成EHTPB/OMMT纳米复合增韧剂引入到环氧树脂体系中;通过傅里叶变换红外光谱(FTIR)、低场核磁(LF-NMR)、扫描电镜(SEM)、静态力学性能测试等,对改性环氧树脂包覆层的结构、增韧机理和力学性能进行了研究,测试了OMMT与EP质量比为0.2∶100样品的抗烧蚀性能和黏结性能。结果表明,当OMMT与EP质量比为0.2∶100时,EHTPB/OMMT/EP包覆层的弹性模量比空白样品降低184.61%,断裂伸长率提高287.55%;线烧蚀率为0.155mm/s,黏结强度为3.84MPa。分析认为,由于EHTPB为环氧树脂基体引入了大量橡胶柔性分子链,而OMMT片层结构能有效进行应力的传递,使体系吸收更多的断裂能,有效阻碍产生的微裂纹的扩散;且OMMT与EP、EHTPB分子链间通过氢键形成交联网络,提高了韧性。

In order to toughen the epoxy resin(EP)coating layer,the organic montmorillonite(OMMT)was peeled off with epoxy butylated hydroxyl(EHTPB)to make EHTPB/OMMT nanocomposite toughener and introduce it into the epoxy resin system.Through Fourier transform infrared spectroscopy(FTIR),low-field nuclear magnetic(LF-NMR),scanning electron microscopy(SEM),static mechanical performance testing,etc.,the structure,toughening mechanism and mechanical properties of the modified epoxy resin coating layer were studied.The ablation resistance and bonding performance of the sample with mass ratio of OMMT and EP of 0.2∶100 were tested.The results show that when the mass ratio of OMMT and EP is 0.2∶100,the elastic modulus of EHTPB/OMMT/EP coating layer decreases by 184.61%compared with that of the referenced sample,while the elongation is increased by 287.55%.The linear ablation rate is 0.155mm/s and the bonding strength is 3.84MPa.It is mainly due to the fact that EHTPB introduces a large number of rubber flexible molecular chains into the epoxy resin matrix,and the OMMT sheet structure can effectively transfer stress,so that the system can absorb more fracture energy and effectively hinder the propagation of microcracks;In addition,OMMT and EP and EHTPB molecular chains form a cross-linked network through hydrogen bonds,which improves toughness.