SIWEI · News
Development and Application of Reinforced and Toughened Filling Masterbatch
With the rapid development of polymer science and technology, society's requirements for polymer materials are also increasing. It is often difficult for a single polymer material to meet this requirement, and it is necessary to modify the polymer material by means of alloying, blending, and compounding (abbreviated as a bc) in order to maximize the characteristics of each component and give a single material Good quality not available. The research and development of high-performance composite materials have become an important part of contemporary high technology and an important development trend of polymer materials. It is moving towards high specific strength, high specific modulus, high toughness, high temperature resistance, corrosion resistance, and resistance. Wear and other developments. Among them, both toughened and reinforced polymer composite materials have become a hotspot of engineering plastics modification research. However, from the perspective of materials science, strength and toughness are two particularly important but contradictory mechanical properties of structural materials. The problem of simultaneous reinforcement and toughening of materials has always been one of the important problems to be solved in polymer materials science. . Generally speaking, the rigid particles filled into the polymer matrix can effectively improve the strength, stiffness and dimensional stability of the material, but at the same time it is very easy to cause the increase of polymer brittleness. Toughening thermoplastics with elastomers, while stiffening, reduces the stiffness, strength, and temperature of the material. The polymer/elastomer/filler three-phase composite material formed by adding rigid particles and rubber at the same time by mechanical blending can balance the contradiction between the rigidity and toughness of the material within a certain range, but it cannot simultaneously obtain high-strength and high-performance polymer materials. . Therefore, since the 1980s, new ways to modify polymers with non-elastomers (rigid particles) have been proposed. Funded by the National Natural Science Foundation of China Key Laboratory, this laboratory first carried out basic and applied basic research on polymer inelastic toughening in China. After years of hard work, we replaced inorganic rubber toughened polymer composite materials with rigid inorganic particles and The toughening mechanism has been systematically studied in depth, and breakthroughs have been made. In theory, it is clarified that in addition to the requirements on the particle size and particle size distribution of the filler, the toughened polymer of inorganic rigid particles must propose a new structural form for its interfacial phase structure, that is, it has good embedding around uniformly dispersed rigid particles The interface is combined with a flexible interface phase of a certain thickness, so that when the material is damaged, it can not only induce silver streaks, stop crack expansion, but also trigger the shear yield of the matrix under certain morphological and structural conditions, thereby dissipating a large amount of impact energy. However, the above-mentioned interfacial phase structure is formed during the reactive extrusion process, the material performance is unstable, the operation cycle is long, and it is difficult to control, so it is difficult to put the high rigidity and high toughness polymer composite material developed in the laboratory into industrialization In the production stage, under the support of the national "863" project, the idea of preparing high-performance composite materials with reinforced and toughened masterbatch was put forward, and under the guidance of this idea, successfully developed reinforced and toughened filler for polypropylene Masterbatch and toughening agent masterbatch for nylon modification. The development of reinforced and toughened filler masterbatch involves a large number of edge disciplines: interface molecular design, physical and chemical modification of filler and polymer surfaces, surface performance characterization, synthesis of interface compatibilizers, interface interaction, rheological behavior, filler dispersion speed And the degree of dispersion, the crystallization behavior of the polymer, the mechanical properties of the material, the mechanism of strengthening and toughening, so it is a very complex and very meaningful. After studying the relationship between the surface properties of inorganic particles, the microstructure of the dispersed phase and the mechanical properties of the materials, we summarized the four basic principles required to prepare high-performance polymer composites with reinforced and toughened filler masterbatch and creatively solved the inorganic The key technical problems of uniform dispersion of particles and interfacial combination are through the use of efficient interface modifiers and the application of reactive extrusion processing methods, and the realization of a small amount of rubber in situ infiltration and coating of inorganic rigid particles has been successfully developed. A new type of polymer/inorganic particle "shell-core" reinforced and toughened filled masterbatch with monodisperse inorganic particles as the core and a small amount of elastomer as the shell. Reinforced and toughened filled masterbatch has the following characteristics: 1. The addition of filled masterbatch not only can significantly improve the processing rheological properties of the polymer, but also can be quickly and evenly dispersed again in the polymer matrix. Therefore, the composite process of filled masterbatch and polymer is simplified from secondary processing to One-time processing becomes possible. 2. The addition of the filler masterbatch increases the modulus and toughness of the polymer composite material at the same time, that is, the modulus and toughness of the material exceed the value of the polymer itself, and a tough and rigid composite material is obtained. Strengthening and toughening effect of filled masterbatch on polypropylene: Filled masterbatch (content 40wt%) Modified polypropylene material Mechanical properties data Homopolymerization pp Masterbatch filled homopolymerization pp copolymerization pp Masterbatch filled copolymerization pp Notched impact strength (j /m) 20 80-90 150 300-400 tensile strength (mpa) 30 25-30 25 20-25 bending strength (mpa) 35 40-50 30 30-36 bending modulus (gpa) 1.0 2.0~2.5 0.8 1.5 -2.0 In many domestic and foreign filled masterbatch commodities and research reports, up to now there have been no reports of highly dispersed filler masterbatch that simultaneously enhances toughened polymer materials. Its successful development has contributed to the improvement of the interface structure model of the inorganic rigid particle reinforced and toughened polymer, the improvement of the interface design and control level of the composite material, and will upgrade China's large variety of general plastics to engineering plastics and further increase in engineering plastics. Performance opens up new ways to broaden new fields for the application of polymer materials and create its due social and economic benefits. At present, the reinforced and toughened filler masterbatch can be used to modify polypropylene and polyethylene plastics, at the same time improve the rigidity and toughness of their materials, and broaden their scope of application. For example, modified polyolefin materials can be applied to automotive and motor vehicle parts , Housings for household appliances, electric toolboxes, etc.
Plastic modified high-tech enterprise