Preparation method of polyolefin-based composite material

Abstract

The invention discloses a preparation method of a polyolefin-based composite material. The preparation method comprises the following steps: dissolving polyolefin in an excessive solvent in a stirringstate at 120-250 DEG C; adding a modifying material, and carrying out stirring and mixing; transferring the mixture into a separator to separate solid from liquid; putting the separated solid into melting equipment; adding an additive into the melting equipment, and carrying out melting and preforming at 110-260 DEG C; and carrying out processing and forming, wherein the solvent is at least one of a liquid silane coupling agent, a liquid titanate coupling agent, a liquid aluminate coupling agent, a liquid phthalic acid ester, a liquid terephthalic acid ester, a liquid trimellitic acid ester,a liquid citric acid ester, salicylic acid, white oil, p-phenylenediamine, fatty acid and maleic anhydride. The prepared composite material is more stable in performance, and the volume resistivity, the thermal deformation temperature and the elongation at break are improved.

Description

technical field [0001] The invention belongs to the technical field of polymer material preparation, and in particular relates to a preparation method of a polyolefin-based composite material. Background technique [0002] Polyolefin is a general term for a class of polymer substances formed by individual polymerization or copolymerization of one or more unsaturated olefin monomers as the basic unit, among which polyethylene (PE) and polypropylene (PP) are the main representatives , also includes poly-1-butene, poly-4-methyl-1-pentene, ethylene-propylene copolymer, ethylene-vinyl acetate (ester) copolymer, ethylene-acrylic acid (ester) copolymer, ethylene-octene copolymer substances, cycloolefin copolymers and other substances. The production of polyolefins is closely related to petrochemical, coal chemical, fine chemical and other industries, and its application fields are very wide, providing a wealth of end products for human clothing, food, housing and transportation. ...

AI Technical Summary

Problems solved by technology

However, these methods all have some defects and deficiencies: 1) solution blending method, which needs to use a large amount of organic solvents, such as o-dichlorobenzene, xylene, trichlorotoluene, etc., which is poor in environmental friendliness and difficult to achieve large-scale production, although Part of the solvent can be recovered by separation, but the remaining solvent is not the formula component of the final composite material. The resulting purification process is time-consuming, energy-consuming, and increases costs. Therefore, this method is often used in small laboratory tests Research; 2) Melt blending method, which adds additives / modifiers and fillers to molten polyolefins to achieve thermal mixing, but molten polyolefins are not highly uniform solvents with large molecular distances , it is difficult to achieve uniform dispersion of solid additives / modifiers and fillers. Therefore, the degree of homogeneity of the final product is low, and there are relatively dense areas of materials in the composite material, which seriously affects its comprehensive performance; 3) In-situ polymerization method, This method needs to pre-modify the polyolefin monomer (introduce functional groups), and then realize the polymerization of the modified monomer under the catalyst to form a modified polyolefin product. The process conditions are harsh and the conversion rate is low. The product contains a catalyst. impurities, and a single product function requires the introduction of additives for secondary compounding; 4) in-situ reduction method, which is mainly for graphene-modified polyolefin composite materials, using polar graphene oxide and polyolefin pre-composite, and then using Reductant reduces graphene oxide to graphene in composites for in situ reduction

However, there are differences in comprehensive performance between graphene and reduced graphene oxide, and the pre-compounding of polar graphene oxide and non-polar polyolefin is also difficult to achieve uniform dispersion, and the subsequent reduction does not help to improve its dispersion; 5) Solvent volatilization This method, which is similar to the solution blending method, requires the use of a large amount of organic solvent, but the solvent is mainly separated from the compound in the form of enhanced volatilization, which requires high energy consumption and time-consuming, and further purification is still required in the later stage of volatilization; 6) Solid phase shearing Grinding method, which first breaks polyolefin and additives / modifications by physical shearing, and then relies on grinding to achieve mixing of all components after adding fillers. There is no combination between different substances, and it is only a simple physical process. Sexual dispersion, no synergistic reinforcement effect, the resulting composite material has poor uniformity and unstable overall performance