SiO_(2)无溶剂纳米流体粒径和含量对环氧树脂力学和热性能的影响

Effect of particle size and content of SiO_(2)solvent-free nanofluid on mechanical and thermal properties of epoxy resin

为了改善纳米二氧化硅(SiO_(2))在树脂基体中的分散性,同时研究SiO_(2)粒径对树脂基体性能的影响,采用Stober法制备了50,90 nm和220 nm三种不同粒径的纳米SiO_(2),并通过表面接枝硅烷偶联剂及聚醚胺的方法制备了相应的SiO_(2)无溶剂纳米流体(NF)。利用红外光谱(FT-IR)、透射电镜(TEM)、热失重(TGA)和差示扫描量热法(DSC)等测试方法对流体的化学结构和物理形貌等理化性质进行了表征。测试了不同粒径和不同含量SiO_(2)纳米流体/环氧树脂(NF/EP)复合材料的力学性能,结果表明,复合材料的力学性能随着流体含量的增加呈现先升后降的趋势;50 nm SiO_(2)流体对环氧树脂冲击性能改善明显,当添加量为1 phr时,弯曲强度增加了11.64%,冲击强度增加了54.55%;而220 nm SiO_(2)流体对弯曲性能改善更为明显,当添加量为1 phr时,弯曲强度提高17.51%,冲击强度提高50.00%。玻璃化转变温度和线膨胀系数测试的结果表明,NF/EP有更高的玻璃化转变温度和更低的线膨胀系数。NF/EP因具有良好的力学性能和低的线膨胀系数,可用作电子灌封树脂。

To improve the dispersibility of the silicon dioxide(SiO_(2))and investigate the effect of particle size on the properties of matrix,50,90 nm and 220 nm nano-SiO_(2)were prepared by Stober method,and SiO_(2)nanofluid(NF)was prepared by grafting the organosilanes and polyether amine on the surface of SiO_(2)nanoparticles.Chemical structure and physical morphology of nanofluid were investigated by Fourier transform infrared spectroscopy(FT-IR),transmission electron microscopy(TEM),thermo gravimetric analysis(TGA)and differential scanning calorimetry(DSC).The mechanical properties of SiO_(2)nanofluid/epoxy resin(NF/EP)composites with different particle sizes and different contents were studied,the results indicate that the mechanical properties of composites are increased first and then decreased with the increase of content.The 50 nm SiO_(2)nanofluid has the best effect on improving impact strength,the impact and bending strength of epoxy resin are enhanced by 54.55%and 11.64%with the 1 phr addition.The 220 nm SiO_(2)nanofluid has the best effect on improving bending properties,the impact and bending strength of epoxy resin are enhanced by 50.00%and 17.51%with the 1 phr addition.The results of the DSC and linear expansion coefficient tests show that the NF/EP composites have higher glass transition temperature and lower linear expansion coefficient than pure epoxy.Thus,with adequate mechanical properties and low coefficient of thermal expansion,NF/EP composites can be considered as promising candidates in the electronic packaging fields.