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Sergeant Major
Join Date: Feb 2011
Posts: 236
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Modified plastics related concepts modified plastic, is in general on the basis of plastics and engineering plastics, after filling, blend, enhanced processing and other methods to improve the flame resistance, strength, impact resistance, toughness and other aspects of performance plastic products. Not only through the modification of plastic components to achieve some of the strength properties of steel, but also with light, colorful, easy to shape a series of advantages, there is currently To find a large-scale alternative plastic material is almost impossible. Involving a wide range of modified plastics, high technology, can create huge economic benefits of a plastic industries. The plastic modification technology - filling, blend and enhance a more in-depth modification of almost all of plastic products, raw materials and molding process. Resin production from raw materials from a variety of specifications and varieties to the modified plastic masterbatch, plastic products in order to reduce costs and improve its functionality, can not do without plastic modification. Plastics often have common characteristics and its own defects, modified plastics is a change to the plastic nature of the basic techniques include: 1, enhanced: the strength of plastic with glass fiber to a change. 2, fill: fill some minerals to the ordinary plastic, the nature of the plastic to change. 3, toughening: a general toughening of plastic adding some toughness make these plastics can be very strong, the modified products: the track pad. 4. Retardant: plastic resin which add to the general flame retardants, flame retardant properties can be made of plastic. Generally have Br + antimony flame retardants, P series, N series, as well as inorganic flame-retardant system. 5. Cold : generally refers to the cold plastic capacity at low temperatures, due to the inherent low-temperature brittle plastic, the plastic become brittle at low temperatures, so like a car inside the plastic, general requirements for cold. charts the role of the role of plastic modification
For example to overcome the limitations
To overcome the processing performance is poor, strong enough to give new features such as defects
Given flame, weathering, high impact resistance, anti-bacterial, anti-static and other new features to reduce costs
PP for minerals such as enhanced toughening of engineering plastics modification, reducing costs is more effective Source: Power handling characteristics of information 2010.01 modified plastics modified plastic with excellent value for money in more and more downstream range of applications, can be said that consumption of modified plastics has become a trend, and this trend is behind the five factors as follows: high: not only have the traditional plastic modified plastics advantages such as low density, corrosion resistance, At the same time physical and mechanical properties very good improvement, such as high strength, high toughness, high impact resistance, wear earthquake, in addition to the improvement of overall performance plastics for a wide range of applications in the downstream areas of the foundation. Low Cost: Compared with other materials, plastic due to high production efficiency, low-density advantage, with lower cost, the cost per unit volume of plastic is only about one-tenth of the metal. Government Policy: the implementation of the Consumer Update: With the improvement of living standards, people began to pursue a more superior product performance, required appliances and other products more attractive, safe, durable, and thus on the upper reaches of the plastics industry more demanding, requiring better processing performance of its , mechanical properties, durability and safety. Technical factors: the world's 1,000 kinds of polymers have been found, but the real value of only a few dozen, not only the development of new polymer huge investment, and application of uncertainty; the contrary, the modification can not only improve the existing performance polymers to meet the needs of industry, and can reduce the cost of some high-priced engineering plastics, the development of the plastics industry as an effective way. Modified plastics and its main sub-types of modified plastics products, consumer groups, the main species are fire-retardant resin, toughening resins, plastic alloys, functionality, the Color Masterbatch and so on. The main sub-chart type of modified plastics, consumer groups and market application categories
Subdivision
Consumer groups
Specific application of flame-retardant resin
Flame-retardant high impact polystyrene resin, flame retardant polypropylene resin, flame-retardant ABS resin
TV manufacturers, computer manufacturers, office appliances (printers, copiers, fax machines, etc.) enterprises, lighting business, electrical business, sound factory
Manufacture of various products, housing, internal components, peripheral equipment (connectors, power strips, plugs), and other enhanced toughening resin
Weather toughening PP Compound
Home appliances business, auto parts enterprises
Production of home appliances and automotive products, glass fiber reinforced thermoplastic internal parts
Computer accessories business, machinery parts enterprises, power tools business, lighting enterprises
Manufacture of computer accessories, machinery parts, power tools and lighting components plastic alloy class
PC alloy products
Electric companies, computer manufacturers, office appliances (printers, copiers, fax machines, etc.) companies, auto parts factory
Production of automotive instrument panels, computer and office automation equipment, power tool housings, PVC alloy products such as cellular phones
Appliance manufacturers, electrical and electronic manufacturers, etc.
Appliance housing, electrical switches, meter enclosure, lighting materials, communications networks, and building materials such as polyester alloys
Automobiles, home appliances, power tools and other enterprises
Automotive parts, appliance parts, power tools, parts and other functions Masterbatch class
Flame-retardant masterbatch of HIPS toughness
TV manufacturers, sound factory
Manufacture of electronic, electrical products, such as Shell Source: Power Information 2010.01 Qin 1, flame-retardant resin fire retardant resin is divided into high impact polystyrene resin, flame retardant polypropylene resin, flame-retardant ABS resin. The product is also divided according to UL94 V0 flame retardant grade level, UL94 V1 level, UL94 V2 and UL94 HB level, such as different levels of flame-retardant specifications, as opposed to ordinary plastic, flame-retardant plastic products can greatly reduce the occurrence of short circuit, overload, water Baptist, etc. generated when the risk of fire. Flame-retardant resin products are the major consumer groups: TV manufacturers, computer manufacturers, office appliances (printers, copiers, fax machines, etc.) business, the lighting business, electrical business, sound factory. Mainly used in the manufacture of various products of the shell, internal parts, peripheral equipment (connectors, power strips, plugs) and so on. 2, reinforcing and toughening resin toughening resin is divided into weather toughened PP Compound, glass fiber reinforced thermoplastic products. 1) The weather toughened PP Compound. Weather toughened PP is a kind of special material properties of polypropylene plastic new material, with a low-temperature toughness, mold shrinkage is small, high rigidity and weather resistance and other advantages, mainly for the required weather resistance, ultraviolet light outdoor environment. The main consumer groups have home appliances business, auto parts enterprises. 2) glass fiber reinforced thermoplastics category. Glass fiber reinforced thermoplastic products are glass fiber reinforced AS / ABS, glass fiber reinforced PP, glass fiber reinforced nylon, glass fiber reinforced PBT / PET, glass fiber reinforced PC, glass fiber reinforced PPE / PPS and other products. The main consumer groups have a computer accessories business, machinery parts enterprises, power tools business, lighting enterprises. 3, plastic Plastic Alloy Alloy Alloy products are divided into PC, PVC and polyester alloy products, alloy products. PC alloy products with high impact strength, creep resistance, heat resistance, low water absorption, non-toxic, excellent dielectric characteristics. Mainly used in automotive instrument panels, computer and office automation equipment, power tool housings, cellular phone. PC alloy of major consumer groups are: electric companies, computer manufacturers, office appliances (printers, copiers, fax machines, etc.) companies, auto parts factory. PVC / ABS alloy is based on PVC and ABS as the matrix, adding toughening agents, lubricants, stabilizers, flame retardants and other production from the modifier, has excellent mechanical and weathering properties, rheological properties, product surface gloss, injection molding, extrusion effect, is a very excellent alloy cost. PVC / ABS alloy weathering alternative flame-retardant ABS, PC, widely used in home appliances shell, electrical switches, meter enclosure, lighting materials, communications network, building materials and so on. Polyester alloys have excellent mechanical properties (fatigue), dimensional stability, chemical reagents, the ability of environmental stress cracking resistance, mainly used in cars, home appliances, power tools and other fields. 4, function Color Masterbatch Color Masterbatch Functional category mainly refers to the flame-retardant masterbatch of HIPS toughness. The parent material and HIPS (high impact polystyrene resin) by a certain proportion (1:2 to 1:30) injection of the product mix to meet the UL94, IEC-65 and GB8898 standards such as electrical appliances, electronic products, the resistance of different fuel requirements, but also can improve the toughness of HIPS resin, process flow and mold release, giving HIPS resin color, not only reduce production cost and improve product quality. Flame-retardant masterbatch of HIPS toughening the main consumer group has a TV manufacturing company, sound factory, mainly used in the manufacture of electronic and electrical products shell. Modification of a plastic commonly used to improve technology to enhance technology fiber reinforced plastic modification of the important ways, magnesium and fiberglass whiskers can effectively improve the overall performance of polypropylene. Glass fiber reinforced polypropylene has a low density, low prices and can be recycled, etc., are being gradually replaced by plastic and metal in the car dashboard, car body and chassis parts in the application: Compared with glass fiber , magnesium whisker molding products have a higher accuracy, dimensional stability and surface finish, preparation of various shapes for complex components, lightweight high-strength flame-retardant components and electrical and electronic components. As a modifier, Magnesium Salt Whisker can greatly improve the strength of polypropylene, stiffness, impact resistance and flame retardant properties. Therefore, the magnesium salt whisker and glass fiber in polypropylene modified in more and more attention. Second, the toughening technology is the most common minerals, toughening modification of one of the ways. Added to the polypropylene raw materials, minerals, usually calcium carbonate, talc, wollastonite, glass beads, mica powder and so on. These minerals not only to a certain extent, improve the mechanical properties of polypropylene and impact toughness, reduce mold shrinkage of polypropylene material to enhance its dimensional stability, and because the minerals and the PP matrix in the cost of the huge difference can greatly reduce the cost of polypropylene. Minerals, toughening polypropylene modified polypropylene materials of all the most widely used in household appliances as a. Currently, Washing Machine and drum washing machines are generally used within the cylinder mineral toughening polypropylene material to replace the stainless steel inner tube early. Strengthening and toughening of polypropylene by mineral, may overcome the lack of its original strength, good gloss, shrinkage and other issues too. At present, this washing machine for the production of polypropylene in addition to outside the inner tube, was also taken for the production of impeller and mouth and other parts of clothing, only the amount of the Haier Group, for its annual tons in 1700 (per washing machine cylinder weighing about 2kg). This material is the amount of minerals added up to 40%, the tensile strength of 33Mpa, elongation at break of more than 90%, the notched impact strength is about 10KJ/m2. Many parts of microwave ovens also use mineral toughening polypropylene material. Since the addition of minerals, can be higher in the polypropylene material itself on the basis of heat resistance, heat resistance to be further improved to meet the requirements of microwave ovens to heat. For example, the microwave oven door's seal, microwave horn speaker, speaker stand, adopted this modified polypropylene. Refrigerator shelves on the basic use of the minerals is now also reinforcing and toughening of polypropylene, glass panels can be due to the overall injection molding, which solves the original problem Qinshui panel ABS material. Third, new high-filled glass filled with modified modified plastics, which can overcome the conventional glass fiber reinforced thermoplastics defects. This material is the high temperature thermoplastic matrix, such as liquid crystal polymer, polyether sulfone, polyether imide, and polyphenylene sulfide. In the glass-filled capacity of 80%, the modified material but still manage a good processability. The production of parts with new materials resistant to wear and the good characteristics of temperature change. This new material can be used with plastic and metal bonding, touch the surface of plastic equipment for processing, the potential applications include automotive and fuel system components, bearings, electronic components, such as anti-scratch cover, this glass reinforcement plus auxiliary flame-retardant efficiency is good, can be recycled, such as highly heat-resistant and dimensionally stable. Fourth, mixing plastic and plastic alloy technology blending modification refers to a resin mixed with one or more other resins (including plastic and rubber), so as to achieve a change in the original resin modification. Fluorine plastic alloy is the use of existing domestic high molecular weight polyethylene FEP (FER) as the main raw materials, and direct mixing PTFE filler, made by physical methods, the material properties over the world recognized the King Fifth, the flame retardant technology polymer technology, mainly to add the current type of brominated flame retardants based, commonly used decaBDE, octa-ether, tetrabromobisphenol A, Hexabromocyclododecane methane, etc., especially in the use of decabromodiphenyl the largest, brominated epoxy resin has excellent melt flow of the rate, the higher flame retardant efficiency, excellent thermal stability and light stability, and flame retardant can be material has good mechanical properties, can not afford to frost, which is widely used in PBT, PET, ABS, nylon 66 and other engineering plastics, thermoplastics to PC / ABS flame retardant plastic alloy processing. Other varieties of flame retardants in the family are phosphorus, triazine system, silicon, intumescent, non-models, etc., these flame retardants used in a variety of different play their unique areas of flame-retardant effect. In the phosphorus flame retardant, organic phosphorus species are mostly liquid oil in the polymer processing is not easy to add, generally in polyurethane foam, transformer oil, cellulose resins, natural and synthetic rubber used. And inorganic phosphorus in the red phosphorus, is pure fire element, fire-retardant effect, but it is bright color, and thus subject to some restrictions apply. The application should pay attention to red phosphorus particles and surface coating, so it has a good in the polymer dispersion, high compatibility with the polymer is good, not easy to move, with a long flame retardant polymer performance. Sixth, nano-composite technology research found that when nanoscale particles to occur when a novel phenomenon, and its periodic boundary is destroyed, making it sound, light, electricity, magnetism, thermodynamics and other properties with the traditional materials showing The great difference. According to the structural characteristics of nano-materials, the different materials were synthesized in the nanometer scale and composition, can form a variety of nano-composite materials such as nano-functional plastic. The types of plastics commonly used in general PP (polypropylene), PE (polyethylene), PVC (polyvinyl chloride), ABS (acrylonitrile - butadiene - styrene), PA (polyamide), PC (polycarbonate) , PS (polystyrene) and dozens of species, to meet the special needs of some industries to use nanotechnology to change the characteristics of traditional plastic, show the excellent physical properties, high strength, heat resistance and strength, lighter weight. With the increasing number of automotive applications, plastics, nanotechnology is likely to be widely used plastic in the car. The Nano-functional plastic automobile industry caused the most attention are flame-retardant plastics, reinforced plastics, plastic UV aging, anti-bacterial plastic. Reinforced plastics are plastics filled by surface treatment of inorganic materials, nano-clay, CaCO3, SiO2, etc., these materials on the crystallization of PP was the convergence of molecular function can make the tensile strength of polypropylene and other plastics, anti- toughness and elastic modulus increased, so that the physical properties of plastics are significantly improved. Toughening plastics can replace metals, due to their proportion of small, light weight, it is widely used in automotive vehicles can significantly reduce the weight to save fuel purposes. These modified with nano-technology enhanced toughening plastics, can be used for car bumpers, seats, fenders, roof cover, door, hood, trunk lid, etc., a transmission box can also be used to , gears and other important components. VII, thermoplastic elastomer technology thermoplastic elastomer referred to as TPE / TPR, with SEBS, SBS to the substrate, are a class of common plastic processing performance, but the text associated with similar products, the performance of rubber polymer alloy. In the multi-material molding, the thermoplastic elastomer has four basic types, namely, styrene block copolymer (SBC), thermoplastic vulcanizate (TPV), thermoplastic polyurethane (TPU) and the multi-ester copolymer (COPE). Thermoplastic polyurethane elastomer is the first to use thermoplastic elastomer processing technology. There are two types of polyester and polyether, polyester with high mechanical properties than the polyester of polyether good hydrolytic stability and low temperature toughness. Polyurethane rubber has good resistance to wear, additives to improve weather resistance, dimensional stability and heat resistance, reduce friction or increase flame resistance, which in various hardness grades have a very wide range of applications in the automotive seals and gaskets , stabilizer bar sets, medical catheters, pacemakers and artificial heart devices, cell phone antenna gears, pulleys, sprockets, chute lining, textile machinery parts, casters, gaskets, diaphragms, couplings and damping components. More ester copolymer elastomer has good dynamic performance, high modulus, high elongation and tear strength, as well as in high and low temperature conditions with good flexural fatigue flexion. Through a combination of UV stabilizers, or carbon black can improve the weather resistance, acid-free oxidation of some aliphatic hydrocarbons, aromatic fuels, alkaline solutions, hydraulic fluids as good or even excellent performance; However, the polarity materials, such as strong inorganic acid and alkali, chlorinated solvents, phenol and cresol make polyester degradation, multi-ester copolymer in general expensive than the thermoplastic elastomer, used in flexible coupling, separated, gear, bellows pad ring, protection cover, seals, shoes soles, electrical connectors, fasteners, knobs and bushes. 2007 World thermoplastic elastomer (TPE) consumption of more than 2.3 million tons, total output value of more than 11 billion U.S. dollars, 2001-2007, maintain an average annual world consumption growth rate of 6.5%. Among them, the North American consumer an average increase of 5.7%, 4.4% Europe, Latin America Zeyi double-digit rate of rapid growth, the Asia-Pacific region is greater than the average annual increase of 8%. High growth industries will drive the use of TP giant, car and daily consumption is driving growth in consumption of thermoplastic elastomer the main factors, different types of thermoplastic elastomers growth is not the same. Currently, the application of thermoplastic polyurethane to an average annual rate of 6.3% growth for the automotive industry in the next commodity thermoplastic polyurethane and the application of sports will be a breakthrough. VIII grafting reaction by one or several monomers of the polymer main chain, connected by a certain way, or by another monomer side chain consisting of several monomer Copolymerization. Polymer modified technology is the most easy to implement a chemical method. Maleic anhydride grafted polymers commonly used twin-screw extruder melt grafting, the Department of class variety, including polyethylene (PE-g-MAH), polypropylene (PP-g-MAH), ABS ( ABS-g-MAH), POE (POE-g-MAH), EPDM (EPDM-g-MAH), with its operation process is simple, low production costs, product quality and stable. MAH graft ratio in which the product in the range of 0.5 to 2.5% of adjustable mechanical properties of the other good. Can be widely used as various non-polar polymers (such as PE, PP, etc.) and polar polymers (such as PC, PET, PA, etc.) the compatibility of its agent when mixed with modified. Nano calcium carbonate is a very important function of the inorganic filler toughening has been widely used in plastics, rubber, paint and paper industry, in order to reduce the high potential energy surface of nano calcium carbonate, regulating hydrophobicity, increased with the base material between the wettability and adhesion, to improve the material properties of nano calcium carbonate be used for surface modification method for surface modification of calcium carbonate mainly fatty acids (salt), titanate, aluminum coupling agent in ester, etc. calcium carbonate surface chemical modification, so that the modification of calcium carbonate filled polymer impact strength is greatly improved, in order to improve the organic matrix and inorganic filler between compatibility with the polymer of organic matter on the surface of inorganic filler connection branches is a common method of modification. Takao Nakatsuka phosphate surface modification of ultrafine CaC03, and then grafted with poly methacrylate, P. Godard and poly butyl by acid adsorption on the CaC03 surface modification of acrylic acid, mixed with acrylic monomers by polymerization better performance PP/CaC03 prepared composite material. Modified plastics technology with newer technology advances the development of science and technology, modern society made of plastic materials, more, more, more stringent requirements. In this case, the general modification methods can not meet the needs of people in recent years, some new modification technology continue to come out and promote the plastics industry. Briefly described below modified in recent years, new technology research and development: liquid crystal liquid crystal modification modification modification technology is relatively new plastic modification means the appearance of liquid crystalline polymers and the unique properties of the plastic modification of the theory and in practice, they added new content. Lyotropic liquid crystal polymer and is divided into thermotropic two categories, it has many good physical, mechanical and chemical properties, such as high temperature, high strength, high elastic modulus, heat distortion temperature much higher than the PPS, PSF, PEI, PEEK and other engineering plastics, a very small linear expansion coefficient, dimensional stability, low melt viscosity, excellent processing behavior, fire-retardant performance, self-lubricating, anti-aging, anti-radiation excellent performance. Take advantage of this high-performance liquid crystal polymer plastic modification of the enhancer as it is developed in the 80s and was called tradition, is considered to be the end of the century one of the significant progress plastics modification. In situ composites is in the process in the matrix liquid crystal polymer resin blends with its rigid rod-like molecules of micro fiber reinforced resin matrix modification methods. PP / LCP (liquid crystal copolyester, a thermotropic liquid crystal) in situ composite system can solve the traditional glass fiber PP increased defects. Hogh et al recently PP / LCP in situ composites were systematically studied using LCP in the easy flow of the molding process to form highly oriented structure, resulting from the enhancement, the LCP for the PP blends, LCP micro-fiber dispersed in PP matrix on which to form in situ composite system. This composite material has good mechanical properties. Chart 1-4 PP, LCP and PP / LCP in situ composites materials bending performance comparison
Bending modulus / Gpa
Bending strength / Gpa PP
1.68
49.6 LCP
13.10
181.2 PP / LCP
4.10
61.7
Source: Power handling information order 2010.01 from the table can be seen: PP / LCP in situ bending properties of composite system is much greater than that of pure PP, the mechanical properties of the system is a major factor in the micro-fiber structure of LCP in PP the dispersion matrix. For PP / LCP in situ composites have better mechanical properties, must ensure that the LCP in PP matrix with uniform distribution. Compatibilizer compatibilizer technological progress plays in the plastic modification of the role of surfactant, the distribution in the surface of two polymers, whose role is to reduce the interfacial tension, increasing interface layer thickness, reducing the dispersed particle diameter, to prevent condensation of the dispersed phase, stable phase morphology has been formed. Plastic modification technology is the key to solving the compatibility of different polymers, whether good or bad compatibility to achieve the purpose of modification. Compatibilizer technology has greatly promoted the progress of plastic modification technology. Compatibilizer is generally divided into non-reactive and reactive compatibilizer compatibilizer (containing acid group-type, epoxy type, isocyanide ester base type, vinyl type). Non-reactive compatibilizer no special functional groups, FPR, SEBS, etc. for this case, in particular, many systems have SEBS compatibilizer effect. Reactive compatibilizer have functional groups in the molecule, which is the alloy composition of one or both react to it formed a compatibilizer material functions, typical examples are maleic anhydride modified PP, ethylene glycidyl methacrylate 2 esters. Many domestic and foreign research institutions are now working on the research compatibilizer, and continue the successful development of a number of excellent performance and compatibility agent. Polyrell has developed a peroxide masterbatch for PP, PE and ethylene-propylene rubber alloy modification; Exxon Exxelor PO 1015, developed higher and more effective response functionality, making it the PA / PP blends excellent compatibilizer; Ameri Hass introduced glutaric copolymer of poly compatible agent, PA, PC blends with the interaction, the use of the compatibilizer, the blends were improved for better balance of the performance of each component before, that blends with the PA of both chemical resistance and processability, but also has a PC, heat resistance and impact resistance. The compatibility of agent and PA, PC can respond to improve the microstructure of the blend, PA in which the continuous phase. Molecular complex technology of molecular composite technology is a small amount of rod-like polymer to the linear chain polymer as a dispersed phase in order to obtain high strength, high modulus of the polymer. Molecular composite technology has entered the practical stage, which in recent years particularly significant areas of progress have been useful in the production of Toyota Motor Corporation of Japan nylon 6 / clay composites, textile companies Toyo PC alloy films. In recent years, developed by Mitsubishi Petrochemical super olefin polymer (SOP) technology is also concerned with the molecular complex. EPR lines in the matrix (including PE copolymers as strong components), the high crystallinity PP copolymer and impact resistance (including talcum powder) Finely dispersed to form a molecular complex structure. SOP in the density, elastic modulus, hardness, low temperature impact resistance, heat resistance and thermal expansion coefficient and other aspects are excellent. IPN IPN materials research technology was first used by Miller, 2, divinylbenzene styrene carried out. The so-called interpenetrating network is two or more polymer chains with each other through mutual entanglement of the mixed system, usually with two or more cross-linked network formation of micro-phase separation structure. This artificial aggregates to form the network structure of polymer blends with the previous blend, graft copolymer of different, cross-linked polymers of various composition, its net chain has the structure of mutual entanglement. IPN technique using modified plastic modification of polymer materials has been a hot issue. IPN technology previously limited to thermosetting resins, high-tech development has exceeded the limits of thermoplastic resin can be formed IPN structure. Examples of typical PU / acrylic resin, PU / POM, TPE / polyester. IPN has become a powerful tool for plastic modification in improving the impact resistance of plastic has been successfully applied. In the PS modified with polybutadiene random, it will be IPN PS modification of the resulting impact properties of materials over the high impact PS, the experimental data the following table illustrates this point. The impact of performance comparison chart of various materials, materials
PS content /%
Izod impact strength / (J / m) PS
100
15.4 HIPS
-
87 polybutadiene / PS IPN
70
116 polybutadiene / PS IPN
85
112
Source: Information 2010.01 reaction force of ground reaction extrusion technology in plastic processing extrusion technology is integrated the two technologies, one plastic in the extruder the synthesis and chemical modification; Second is the plastics processing and forming. Reactive extrusion requires a high reaction capacity of raw materials containing functional groups, and the faster the reaction should be completed within a few seconds to ten minutes, and should be a low exothermic reaction. Reactive extrusion screw has a large aspect ratio requirements, and along the barrel length can easily add and remove various volatile reactants. Reactive extrusion compatibilization generally have 3 types: functional components of the blend, adding polymer compatibilizer, adding low molecular weight compatibilizer. (1) has been functionalized with the compatibility of the polymer in situ. Commonly used reactive groups are carboxyl, epoxy, ester and ester anhydride isocyanide. (2) add a third polymer, which should together with the blend of the reaction, and then through the covalent bond or ionic bond compatibility of role play. (3) low molecular weight compounds by copolymerization or cross-linked to form a copolymer or cross-linked material. In the reactive extrusion technology is the most widely used maleic anhydride (MA) is introduced into a variety of material. As one of maleic anhydride with C = C double bond, with a radical and photochemical reactions involved in the ability to; on the other hand anhydride groups can contain active hydrogen from the reaction of some elements, such as amidation, esterification and so on. Therefore, MA can be used in the C = C double bond of the radical reaction to the polymer chains grafted to a variety. This anhydride polymer polarity and increased functionality, which has all the ability to respond. In recent years, the MA in the polyolefin has a lot of research reports, and has been widely used, mainly in the following areas: (1) With the introduction of polar groups anhydride can be used in three types of polymers: polyolefin, poly double-olefins and polar polymers such as PP, PE, poly butadiene, PVC, PA and EVA, can be grafted MA. (2) the formation of comb-type branched structure. (3) cross-linked network formation. Polymer a certain amount of presence of ionic crosslinks to form cross-linked network structure, the polymer has the properties of ionomers. (4) interface compatibilization, as in the PA / PP PP2g2MA adding a small amount of compatibilizer can play a role, so easy to micro-phase distribution of PP to the PA. (5) Preparation of fluorescent polymer. (6) coupling effect and the bonding effect. The technical status of modified plastics in China although the domestic industry, despite the modification of plastics, there are many shortcomings, but some technologies and products have reached international advanced level. Mainly in the following areas: 1, special resin: foreign enterprises in order to produce specific grades of resin, specifically the main purposes, and our Zeyi common resin-based resin, modified to make it compatible with the characteristics and uses to be resin, and the domestic petrochemical enterprises which produce less relevant special conditions of synthetic resins. 2, the inorganic powder material modification: in the field of technical standards of living in an international leading position. Foreign companies not to fill as a means of reducing costs, but the use of performance requirements should be packing products, door and window profile which reflects the product was particularly prominent. 3, the use of waste plastic: living in China in the leading position in this regard. The attitude of foreign countries against one abandoned waste plastics Sinotrans, the second is to use low level processing, and waste plastics in China as the necessary complement of synthetic resin materials, such as flame-retardant ABs, PC / ABS alloy modified with waste plastic after , can be used as a raw material for plastic products. 4, modified with additives and additives: China in the modified additives, additives on the R & D has made significant progress. Coupling agent, antistatic agents, flame retardants to meet the basic requirements, the main manufacturers is the lack of individual pursuit of profit, and malicious changes in product composition, resulting in lower quality, functional instability; RE agent, nucleating agent, water magnesium powder, etc. As our country has the resources, in a leading position in the international arena. 5, mechanical equipment manufacturing industry: China modified plastics commonly used in high-speed mixer, parallel twin-screw extruder and continuous operation in the use of functional aspects of life have reached the international advanced level, but the price is far lower than the average international market price. Suitable for thermal shear-sensitive material modification and mixing of the reciprocating single screw extruder has also been large-scale production, breaking the monopoly by foreign companies, and effectively promote the diversification of modified and high performance plastic products of the development.
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