多巴胺修饰氮化硼对环氧树脂复合材料性能的影响

Impact of Dopamine Modified Boron Nitride on the Properties of Epoxy Resin Composites

通过多巴胺(DA)和聚乙烯亚胺(PEI)共沉积,在纳米氮化硼(BN)表面引入氨基和羟基等活性基团,增强BN与环氧树脂(EP)基体之间的应力载荷传递。采用热失重分析仪、傅里叶变换红外光谱(FTIR)仪、X射线光电子能谱(XPS)仪及场发射扫描电子显微镜(FSEM)表征了BN纳米片的结构和形貌,研究了其对环氧树脂拉伸强度、断裂韧性以及热稳定性的影响。结果表明,改性BN/DA-PEI纳米片的加入,提高了EP的热稳定性和动态力学性能;与纯EP相比,含有1%(质量分数)BN/DA-PEI的环氧树脂复合材料的拉伸强度、断裂伸长率和临界应力强度因子(K IC)值分别提升了43.3%、30.8%和129.7%;EP/BN-DA-PEI复合材料的初始储能模量比纯EP提高了1 063 MPa,玻璃化转变温度(T g)从167℃升高到178℃。

For the sake of enhancing the stress load transfer between boron nitride (BN) and epoxy (EP) matrix, amino groups and hydroxyl groups were introduced on the surface of BN through co-deposition of dopamine (DA) and polyethyleneimine (PEI). The chemical bonds formed between the amine functional groups on the BN surface and the epoxy resin during curing provided strong sheet/matrix interfacial adhesion, and improved the dispersion of BN in EP matrix. Thermogravimetric analyzer (TGA), Fourier transform infrared spectrometer (FTIR), X-ray photoelectron spectroscope (XPS) and field emission scanning electron microscope (FSEM) were employed to characterize the structure and morpho-logy of the modified BN. Furthermore, the effect of addition of BN and modified BN on the tensile strength, fracture toughness ( K IC ) and thermal stability were investigated. The results demonstrated that the introduction of DA-PEI modified BN greatly contributed to enhancing the thermal stability and dynamic mechanical properties. Specifically, epoxy composite containing 1wt% of BN-DA-PEI nanosheets showed a remarkable improvement in tensile strength, elongation at break and K IC by 43.3%, 30.8% and 129.7%, respectively. Meanwhile, the EP/BN-DA-PEI composite showed an sharp increase of 1 063 Mpa in storage modulus compared to pure PE, as well as an increase of glass transition temperature ( T g) from 167 ℃ to 178 ℃.