硅烷偶联剂KH550改性白炭黑及其在环氧树脂中的应用

Study on Surface Modifi cation of Silica with KH550 and Its Application in Epoxy Resin

利用硅烷偶联剂KH550对白炭黑纳米粉体进行表面接枝改性,并制备改性白炭黑(m Si O_(2))/环氧树脂(EP)浇铸体,利用傅里叶变换红外光谱(FTIR)、X射线衍射(XRD)、粒度分析、拉伸性能测试、热重分析(TG)、扫描电镜(SEM)等手段对改性前后的白炭黑粒、m Si O_(2)/EP浇铸体进行表征分析,探究了KH550对白炭黑的改性效果以及m Si O_(2)用量对浇铸体力学性能、耐热性和结构的影响。结果表明:以异丙醇作为分散剂,当KH550质量分数为20%,反应温度为90℃,反应时间为5h,在醇、水混合溶剂中可以实现KH550对白炭黑的表面改性;当改性白炭黑用量为8%(wt.)时,浇铸体综合性能最好,拉伸强度为41.29MPa,较纯EP提升了95.2%;其最大分解速率时的温度为377℃,较纯EP提升了14℃。

The silane coupling agent KH550 was used to modify the silica by surface grafting and to prepare modified silica(mSiO_(2))/epoxy resin(EP)casts.The silica pellets and mSiO_(2)/EP casts before and after modification were characterised by means of Fourier transform infrared spectroscopy(FTIR),X-ray diffraction(XRD),particle size analysis,tensile properties testing,thermogravimetric analysis(TG)and scanning electron microscopy(SEM).The effect of KH550 on the modification of silica and the effect of mSiO_(2) dosage on the mechanical properties,heat resistance and structure of the cast body were investigated.The results show that the surface modification of silica by KH550 can be achieved in a mixed solvent of alcohol and water when the mass fraction of KH550 is 20%,the reaction temperature is 90°C and the reaction time is 5h,using isopropanol as the dispersant.Furthermore,the mechanical properties and thermal stability of the mSiO_(2)/EP composites were improved by the KH550 modification.When the amount of mSiO_(2) was 8%(wt.),the tensile strength of the mSiO_(2)/EP composite exhibited 41.29MPa,which resulted in an increase of tensile strength by 95.2%,and a maximum decomposition rate temperature of 377°C,which is 14°C higher than that of pure EP materials.