纳米TiO2和SiO2填充EVA复合材料的结构与性能

采用一步法制备出EVA/纳米T iO2及EVA/纳米S iO2复合材料,研究纳米微粒在EVA基体中的分散性、结构变化及对力学性能、流变性能的影响。结果表明,加入的纳米微粒粒径越小,纳米粉体在基体中的分散就会更加均匀,分散微粒的粒径也会更小;纳米微粒和硅烷偶联剂之间,硅烷偶联剂和EVA之间会形成一定的键合结构。适量的纳米微粒能够改变断裂机理,有效地提高材料的力学性能,降低熔体的表观黏度,从而改善加工流动性。

Structure and Properties of EVA Composites Filled with Nano-TiO2 and Nano- SiO2

Ethylene-vinyl acetate copolymer(EVA)/nano-TiO_2 and EVA/nano-SiO_2 composites were prepared by 'one-pot' technique.The dispersion and structure change of different nano-particles in the same polymer matrix were studied.The influences on the mechanical and rheological properties of the composites were also discussed.The results show that size of the nano-particles play very important roles in dispersion of nano-powder in EVA matrix.The smaller the grain size of nano-particles,nano-powders was more evenly distributed throughout the EVA matrix and the nano-particles dispersed in the EVA matrix was becoming smaller.The bonding between the nano-particles and the vinyltriethoxysilane,the vinyltriethoxysilane and the EVA matrix,as can be proved by the FT-IR spectra of the composites.The nano-particles toughen EVA/nano-particles composites when nano-particles content reaches a certain value.The tensile strength and elongation at break of composites are also increased.Further,the composites show an unusual rheological behavior.The apparent viscosity of nano-composite melt is lower than the pure EVA.And the process flowability of composites is notably raised.