Preparation method of organic montmorillonite for polyolefin composite material

Abstract

The invention relates to a preparation method of organic montmorillonite for a polyolefin composite material, and belongs to the deep processing technical field of the montmorillonite. The preparation method is characterized by comprising the steps of modifying montmorillonite by using short-chain organic cation quaternary ammonium salt; carrying out high-speed stirring reaction with nano silicon dioxide at the same time; and finally, centrifuging, drying and crushing, wherein adding amount of the organic cation quaternary ammonium salt is 0.8-1.2 times exchange capacity of the montmorillonite cations, and the adding amount of the silicon dioxide is 5%-20% the weight of the montmorillonite. According to the preparation method, intercalation of the montmorillonite is firstly carried out by using organic cations to change polarity of the organic montmorillonite and increase compatibility with the polyolefin material; meanwhile, the montmorillonite is compounded with nano silicon dioxide, so that interlayer spacing of the montmorillonite is further expanded, thermal degradation of organic cations can be restrained, color requirements of the composite material are satisfied, and therefore, the preparation method can be effectively used for the organic montmorillonite powder of the polyolefin material.

Description

technical field [0001] The invention relates to a preparation method of organic montmorillonite for polyolefin composite materials. Background technique [0002] The principle of organic treatment of montmorillonite is to use organic cations to replace the original cations between the crystal layers of montmorillonite particles, so as to change the interlayer structure, reduce the surface energy of montmorillonite sheets, and increase the affinity between the two phases. properties, and then prepare montmorillonite / polyolefin nanocomposites, in which the montmorillonite sheets are uniformly distributed in the polyolefin matrix with nanometer size (at least one dimension less than 100nm) in the structure of the material, through the montmorillonite nanosheets Small size effect, surface and interface effect, and quantum effect can make polyolefin materials improve their physical, mechanical properties and heat resistance with very little filler (generally less than 5wt%), and ...

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Problems solved by technology

[0009] Chinese patent 200510002216.2 disperses nano-montmorillonite in an organic solvent, and then adds an organic modifier soluble in organic reagents to prepare montmorillonite with a layer spacing greater than 1.9 nanometers. This method avoids the montmorillonite when it is dispersed in water. The process of replacing from the aqueous phase to the organic phase simplifies the preparation method, but this method uses a large amount of organic solvents, and most of the organic solvents are toxic reagents, so there are risk factors in the preparation process and subsequent treatment process, which is not suitable for industrial production

[0010] Chinese patent 99119834.4 is made by reacting the aqueous phase suspension of montmorillonite with a quaternary ammonium salt compound and polyunsaturated carboxylic acid derivatives. Polyunsaturated carboxylic acid can improve the solvation dispersion ability in solvent, but polyunsaturated carboxylic acid Acid derivatives can only play the role of adsorption on the surface of montmorillonite, and cannot increase the interlayer distance of montmorillonite

[0011] Chinese patent 200910223929.X introduces a preparation method of silica / inorganic clay composite powder. This patent uses wet mixing and stirring of inorganic clay and silica to obtain inorganic composite powder after drying. The preparation method is simple and easy. However, due to the hydrophilicity of inorganic clay, it cannot form effective nanocomposites with most polymers. Therefore, it is necessary to select a suitable organic modifier to exchange the inorganic cations between the clay layers to achieve the purpose of organicizing the clay. So it has better compatibility with organic polymer materials

[0012] The organic modification method of montmorillonite for polyolefin composite materials introduced in the above patents is mainly through the intercalation modification method of organic quaternary ammonium salts. Most of the selected reagents are long-chain quaternary ammonium salts, which have the advantages of large dosage and high cost. characteristics, and thermal decomposition will occur during the melt extrusion process of polyolefin composite materials, making plastic products turn yellow and black

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