直接注射法制备LLDPE／有机蒙脱土纳米复合材料及其表征

Preparation and Characterization of LLDPE/OMMT Nano-composite by Direct Injection Moulding

自制一种有机蒙脱土,对其进行处理得到另外两种有机蒙脱土。XRD测试结果表明:与天然蒙脱土相比,三种有机蒙脱土层间距明显增大;在不加任何相容剂的条件下,将三种有机蒙脱土采用注射成型法分别与LLDPE制备出三种复合材料。利用TEM观察三种复合材料发现,经过后处理的有机蒙脱土与LLDPE复合后其分散粒径更小,基本形成了剥离型的纳米复合材料,且层间距愈大的有机蒙脱土分散愈均匀,粒径越小。三种纳米复合材料的应力-应变曲线表明,剥离型的纳米复合材料拉伸曲线出现了明显的屈服点,屈服强度、断裂强度、拉伸模量都有明显提高,说明这两种纳米复合材料中产生了明显的结晶相。研究表明有机蒙脱土层间距的增大有利于聚合物的插层及其在聚合物中分散,从而形成剥离型的纳米复合材料;对于进一步研究聚乙烯纳米大棚膜等薄膜材料的阻隔性、防雾滴性,保温性等方面奠定了良好的基础。

One type of sel-made organic montmorillonite （OMMT） was prepared, which was then treated to prepared another two types of organic OMMT. The XRD testing results of the prepared products showed the layer spaces of later two types OMMT were larger than that of the original one. Three types of nano-composites were prepared directly by injection moulding of LLDPE with the three types of OMMT respectively. TEM observations indicated the modified OMMT exfoliated in the LLDPE matrix and the particle diameters were finer, the OMMT with the largest spacing dispersed homogeneously in the matrix, having more fine particle diameters. The curves of stress- strain showed the tensile curves of the exfoliated nano-composites had an obvious yield point, and the yield strength, bending strength and tensile modulus of the composites were upgraded notably, which showed there had crystalline phases in the composites. The results also showed the increase of the interlamellar space of the OMMT was of benefit to the intercalation and dispersion in the polymer, resulted in forming exfoliated nano-composlte, and established the foundation for the further studies of the barrier property, anti-fogging and thermal insulation of PE nano-composite green house films.