Enhancing type polyolefin/clay nanocomposite and preparing method thereof

Abstract

The invention relates to an enhancing type polyolefin / clay nanocomposite which is prepared from polyolefin and modified clay in a melt blending and aggregation mode. The modified clay is prepared through reaction and pretreatment through a coupling agent containing double bonds; the clay comprises SiO2 and Al2O3, and the clay is aluminosilicate mineral dust with the granularity smaller than 200 meshes and a layered or fibroid structure. According to the enhancing type polyolefin / clay nanocomposite, a reaction with quaternary ammonium salt is not needed, the clay is dispersed in a solvent first and then reacts with the coupling agent containing double bonds, and the modified clay is obtained. The double bonds of the coupling agent are opened in the melt blending process through a reaction blending method and react with polyolefin and derivatives of polyolefin, and strong interaction of chemical bonds between the clay and polyolefin and between the clay and the derivatives of the polyolefin is established. The clay is evenly dispersed in the polymer through the shearing force of a screw, and the thus the mechanical property and the performance on other aspects of the materials are greatly improved.

Description

technical field [0001] The invention relates to the technical field of nanocomposite materials, in particular to a reinforced polyolefin / clay nanocomposite material and a preparation method thereof. Background technique [0002] In recent years, in order to improve the mechanical and gas barrier properties of polyolefins, many scientific research institutions and companies have tried to prepare polyolefin / clay nanocomposites. The clay sheet itself has excellent characteristics such as extremely high modulus and strength, and a large specific surface area. Adding it to the polymer in a suitable way can greatly improve the performance of the obtained product and expand its application field. [0003] Generally speaking, there are three ways to prepare polymer / clay nanocomposites: solution method, in-situ polymerization method and melt blending method. The solution method needs to dissolve or stably disperse the polymer and the filler clay in an appropriate solvent at the sam...

AI Technical Summary

Problems solved by technology

There are fewer functional groups naturally present on the surface of clay, resulting in poor interface properties between clay and polymer matrix, and the external force on the material cannot be transmitted to the rigid filler, thus greatly weakening the reinforcing effect of the filler

In extreme cases, fillers can even be transformed into external impurities, inducing premature failure and fracture of the material

At the same time, the thermal stability of quaternary ammonium salts is low, which seriously limits its application in some high melting point polymers

However, the introduction of active groups through the direct reaction of the coupling agent with the hydroxyl groups of the clay sheet sections is limited by the number of reactive hydroxyl groups on the clay surface, and it is difficult to greatly improve the interfacial properties of the clay.

At the same time, due to the polarity difference between clay and polymer, it is often necessary to add compatibilizers in the process of preparing composite materials, such as maleic anhydride grafted polymers, etc., which increases production costs

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