Valuable Polypropylene Modified Products

Polypropylene (PP) is a versatile plastic resin with a wide range of sources and low cost, and has a very wide range of uses. However, due to the high brittleness (especially low-temperature brittleness), high crystallinity, and low molecular polarity, the blending and adhesion of PP with other polymers (such as plastics, rubbers) and inorganic fillers is poor, limiting its Some areas of application.
In the early 1990s, the United States advanced the advanced solid-phase graft modification method and has now developed related products such as Eastman's chlorinated modified PP (MCPP) resin, which is priced at a price per ton in the Chinese market. More than 500,000 yuan. Modified PP (MPP) and MCPP as special PP special materials, greatly expanding the scope of application of PP, with great economic benefits.
The solid-phase grafting method was used to modify isotactic PP to obtain MPP, and then MPP was chlorinated to obtain MCPP solid powdered resin. The chlorinated modified resin has a strong adhesion, an increase in the tensile modulus, and is easily blended with other resins; and due to the modification, the crystallinity of the PP is impaired and the polarity thereof is increased, so that it can be dissolved in some solvents and can be prepared differently. The concentration of MCPP solution.
Uses of MPP (1) Improve the impact resistance of engineering plastics. With MPP as a compatibilizer, the impact strength of blends made of PP and other plastics is increased by 2-3 times, and can be used as an impact-resistant housing material. The Dexpro alloy developed by Dexfer Plastics, which is an alloy of polyamide and PP in the presence of a compatibilizer, is now commercialized.
(2) It is used as a thermal plastic powder coating for the surface of metal substrates to play an anti-corrosion and chemical resistance. Japan's Nozagl-GIZ grade is an alloy of PP and nylon, with high chemical resistance and oil resistance, especially with excellent resistance to potassium chloride.
(3) Improve the adhesion of PP fillers. The introduction of MPP can improve the compatibility of filler and PP, improve the performance of composite materials, and improve the overall thermal stability and local heat resistance of the material.
(4) MPP is also applied to the curing of radical active waste.
In addition, MPP can also be used to improve the dyeability of PP fibers and plastic products can be decorated to create retort packaging materials.
From the market point of view, the total domestic demand for PP is more than 3.5 million tons per year, of which PP-specific material is more than 1 million tons. The grafted PP modified demand is calculated at 100,000 t/a. It is mainly used for: blending with other polymer materials such as nylon, polycarbonate, and rubber to prepare new polymer materials; adding fillers such as inorganic powders , glass fiber, natural fiber, etc., to prepare high-strength PP; further processed products for powder coatings, liquid coatings, etc.
At present, China's isotactic PP solid-phase graft modification method is still blank, there is no such product into the market, the vacancy mainly depends on imports, the German company Hoster specializing in the promotion of modified PP products in China is sold for 15,000 -1.8 Million/t.
The use of MCPP (1) for the preparation of plastic primer and plastic surface decorative coating adhesion promoter, in particular, car bumpers, hub caps, TV chassis and other civilian and industrial plastics coating.
(2) It is widely used as a plastic printing ink resin.
(3) It is used as anti-corrosion coating resin for the heavy-duty anti-corrosion field of steel slaughter, aluminum and other materials.
With the large-scale use of plastic products, people pay more and more attention to the decoration of plastic surfaces. However, due to the low surface energy of plastic products, there are problems such as difficulty in direct coating and poor adhesion. Usually, the plastic surface needs to be surface-treated before coating. There are two main methods. One is the use of flame, corona discharge, gas plasma, etc. for surface treatment. Difficulty in this type of technology is that a uniform surface must not be formed and that excessive processing is not performed. Otherwise, the polymer chains on the surface will be broken and the material properties will be affected. The second is the use of a surface primer for surface treatment. Among them, chlorinated polyolefin (CPO) is an ideal primer resin that can be used to prepare adhesion-enhancing primers or as adhesion promoting additives. For example, Eastman USA has industrialized Fastman CP164-1 solvent-based product (xylene solution with a solid content of 25%) and CP310W and CP347W water-based products. It is reported that Eastman's 25% CPO solution has a domestic market price of RMB 125/kg. Recently patents have also been reported on acrylic polyurethane paint containing CPO resin, which can be used as a one-off top coat; epoxy/MCPP coatings are a good type of anti-corrosion paint with good acid and alkali resistance.
The demand for surface coating of MCPP resin automotive plastic parts is 500t/a or more, and the demand for metal surface anti-corrosion coatings is more than 200,000t. In terms of printing inks, the current market demand is above 500t/a. At present, Guangzhou Zhujiang Electrochemical Plant uses solid-phase suspension chlorination to produce unmodified chlorinated PP, with a production capacity of 30,000 t/a. The product is very popular and sells for about 35,000 yuan/t. The American MCPS solid material produced by Eastman Company has a domestic price as high as 500,000 yuan/t, and 50% of MCPP's solution price is about 270,000 yuan/t.
As a functional product of PP, PP modified product can greatly broaden the application of PP, has a wide range of market and application prospects, and is worthy of vigorous development.