改性纳米SiO2／LLDPE／LDPE复合薄膜性能的研究

Study on Properties of Modified Nano-SiO_2/LLDPE/LDPE Composite Membrane

采用母粒法,经过熔融共混制备SiO2/LLDPE/LDPE混合材料,研究了该复合材料的力学性能、光学性能。结果发现:纳米SiO2对聚乙烯有一定的结晶成核作用,填充纳米SiO2的改性PE混合体系的球晶尺寸明显小于纯PE体系;随着纳米SiO2用量的增大,复合材料的拉伸强度和断裂伸长率和冲击强度呈峰形变化,在粉体质量分数为3%时达到最大;复合材料薄膜对长波红外线(7～11μm)的吸收能力较LLDPE膜有了显著提高,透光率略有下降但雾度提高,透光质量得到改善;同时表明,纳米SiO2的表面处理方法对膜的光学性能有显著影响。

In this paper composites were prepared by coupling to the nano SiO2 precipitation into the linear low density polyethylene （LLDPE） / low density polyethylene （LDPE） hybrid system, then the blown film extrusion blow molding system film, a film on the mechanical properties, optical properties. The results showed that SiO2 nanopowder could induce crystallization of polyethylene （PE）, the sphemlites of the crystal decreased with the increase of SiO 2 content; with the increase in nano SiO 2, composite materials, the tensile strength and elongation at fracture, the first increase after the decrease in the powder content of 3% maximum. The IR absorptivity （ ranging from 7 um to 11 um） of the composite films increased dramatically with the nano SiO 2 introduced. Although the visible light transmittance of the film declined a little compared with the pure LLDPE. the haze value increased much. It was also found that the surface treatment method of nano SiO 2 had great influence on the optical properties of the composite films. The infrared absorptive and haze of the composites filled-with nano SiO 2 treated by silan ecoupling agent in ethanol were superior to those of the composites filled with nano SiO2 treated by silane coupling agent in a ball mill, because the former had smaller particle size and more uniform dispersion in matrix than the latter.