聚苯乙烯改性纳米SiO_2/低密度聚乙烯接枝聚苯乙烯复合材料的制备及表征

为制备接枝聚乙烯与SiO2的复合材料,赋予其新的特殊性能,首先,通过预辐照和悬浮接枝技术制备了低密度聚乙烯接枝聚苯乙烯(LDPE-g-PS),通过表面接枝制备了PS改性纳米SiO2(PS@nano-SiO2);然后,将LDPE-g-PS与PS@nano-SiO2熔融共混,制备了PS@nano-SiO2/LDPE-g-PS复合材料;最后,利用FTIR、SEM、DSC和电子拉力机等对材料的结构及性能进行了研究。结果表明:PS已经分别接枝到LDPE和纳米SiO2上;在PS@nano-SiO2/LDPE-g-PS复合材料中,SiO2在LDPE-g-PS内达到纳米级分散,并形成独特的纤维状网络结构;2wt%PS@nano-SiO2/LDPE-g-PS复合材料的冲击强度比LDPE-g-PS提高了99.3%;与LDPE-g-PS相比,PS@nano-SiO2/LDPE-g-PS复合材料的结晶温度升高,击穿场强比LDPE的高1.4倍。所得结论表明PS@nanoSiO2/LDPE-g-PS复合材料的性能较好。

Preparation and characterization of polyethylene modified nano-SiO2/low-density polyethylene graft polystyrene composites

In order to prepare the composites of grafted polyethylene and SiO₂, and endow it with new special properties, low-density polyethylene graft polystyrene (LDPE-g-PS) was prepared by pre-irradiation and suspension graft technique firstly, and PS modified nano-SiO₂ (PS@nano-SiO₂) were prepared by surface grafting. Then, PS@nano-SiO₂/LDPE-g-PS composites were prepared by melt blend of LDPE-g-PS and PS@nano-SiO₂. Finally, the structures and properties of the materials were investigated by FTIR, SEM, DSC and electronic tensile machine etc. The results indicate that the PS has been grafted onto LDPE and nano-SiO₂ respectively. In PS@nano-SiO₂/LDPE-g-PS composites, SiO₂ reaches nano-scale dispersion in LDPE-g-PS, and forms unique fibrous network structure. The impact strength of 2wt% PS@nano-SiO₂/LDPE-g-PS composite improves by 99.3% comparing with that of LDPE-g-PS. Comparing with LDPE-g-PS, crystallization temperature of PS@nano-SiO₂/LDPE-g-PS composite increases, and the breakdown field strength is 1.4 times higher than that of LDPE. The conclusions obtained show that the properties of PS@nano-SiO₂/LDPE-g-PS composites are better.