1. Foreword With the technological advancement of polymer material synthesis and processing, plastic has been widely and deeply applied in various industries. The plastic products used in various industries are very different, and the requirements on the materials and properties of the products have their own particularities. Plastic auxiliaries, resin raw materials and plastic processing machines together form the three basic elements of plastic processing. In addition, the level of processing technology, formulation technology, and related supporting service facilities are also indispensable factors for the perfect display of the performance of plastic products. According to statistics, in 2001, the global consumption of plastic auxiliaries reached 7900 kt, with sales of 14.6 billion U.S. dollars, of which functional auxiliaries accounted for about 80%. Some new functional auxiliaries have not been developed for a long time and have low consumption, but they have brought new breakthroughs and growth points to the auxiliary industry. They have enriched and improved the entire auxiliary system, and its high-tech content and huge increase have shown strong vitality. At the same time, traditional additives are also trying to find new alternatives. The single structure corresponds to a single performance and is still the theoretical basis for research and design of the molecular structure of auxiliaries. However, new ideas such as compounding, macromolecular quantification, and environmental protection gradually occupy the main line of new research and development. A multi-functional and single-agent single-function high-performance has become the trend of modern additives research and development. While emphasizing functional expression, people have put more attention on issues such as processing applicability, formulation design, and later recycling and harmless treatment in the earlier period. This has made the structure of the auxiliary research more reasonable and has developed more. For balance. In addition, basic theoretical research in scientific research institutes and colleges and universities should be combined with modern enterprises, and they should be quickly and better invested in industrialized production. Increasing input in applied research is also a problem that auxiliaries experts and entrepreneurs need to consider and face.
China's auxiliary industry started late, and development is slow, it is difficult to adapt to the current development trend, we must rely on the development of the industry to explore a path with additives with Chinese characteristics. Based on the digestion, absorption, and imitation of foreign advanced varieties and technologies, we have developed highly efficient, versatile, compound, low (no), low (no), and specialized additives for different industries. , To increase the scale of production and management capabilities, change the current small-scale additives industry, variety, performance, aging and similarity, targeted (dedicated) poor, performance-cost ratio is significantly lower than similar foreign products, low innovation capacity, serious pollution, The disorderly competition situation creates a new industry with a significantly higher input-to-output ratio than other chemical products.
2. Improvement of Traditional Additives 2.1 The purpose of composite compounding is to find an additive that makes it versatile and meets the needs of multiple functions. The new composite technology is based on the study of classical theory and applied technology, and combines additive components that show synergistic effects or different functions to form a composite or masterbatch, regardless of the development or application of additives. The fact that it has a multiplier effect is also an important reason why composite technology has attracted much attention.
The compounding of auxiliaries includes mixed auxiliaries and concentrated master batches. The former is a mixture of various additives, and the latter is attached to the carrier resin at a relatively high concentration of auxiliary agents, dispersants, etc., and diluted a certain number of times during processing. The common feature of composite technology is the simple and convenient application of additives. Therefore, the composite technology has penetrated into various fields of plastic additives. Compared with the earlier simple complex additives, the composite technology of contemporary additives has made a quantum leap, and the role of the synergistic components is very critical and outstanding. The study of the synergistic mechanism between the various components and the development of synergistic components will be the key to the development of auxiliary compounding technology in the future.
The Chemical Industry Research Institute of Beijing Municipality combined a high molecular weight hindered amine light stabilizer and a number of light and heat stabilizers with high thermal stability and metal ion chelating properties into a new BW-6911 light stabilizer. 6911/B215 anti-aging system. 6911 The use of special coupling technology to hold together hindered amine stabilizers of different structures not only reduces the migration rate of the light stabilizers in the resin, but also exerts the synergistic effect of the hindered amine stabilizers with different structures and increases the resistance. The ability of long-term high-temperature oxidative degradation effectively solves the problem of the cracking of the shed film at the frame of the greenhouse due to the “back plate effect†during the high temperature season. This is a problem that cannot be solved by the general anti-aging systems such as 622, 944 and GW540. 1,2]. The new composite antioxidants and GX2225 introduced by Ciba Specialty Chemicals are compounded by the introduction of the benzofuranone compound HP-136 into traditional composite antioxidants B215 and B225. HP-136 can capture the carbon radicals directly produced by polymer degradation and block the degradation chain reaction. The GX2215 allows polyolefins and other polymer materials to maintain excellent stability during high temperature processing.
2.2 Macromolecule Quantification The macromolecular quantification can improve the thermal stability, hydrolysis resistance of the auxiliaries themselves, increase the compatibility between the auxiliaries and the base resin, and improve the migration resistance and extraction resistance of the auxiliaries in the plastic products. Without excessively deteriorating the basic physical and mechanical properties of the substrate. High molecular weight is also an effective means to reduce the toxicity of the additives themselves. The high molecular weight antioxidant 1010 is significantly improved in hydrolysis resistance, migration resistance, and extraction resistance compared to the low molecular weight 1076. Polymeric antistatic agents provide permanent antistatic properties. High-molecular-weight flame retardants such as oligo-phosphonium bromide and oligo-phosphatidic acid esters significantly reduce the degree of deterioration of other basic physical and mechanical properties other than flame retardancy. The molecular weight of hindered amine light stabilizer (HAL S) can not only improve the thermal stability, compatibility with the resin, migration resistance, and extraction resistance, but also reduce the toxicity, prolong the service life of plastic products, and expand their use .
2.3 Environment-friendly The deep and wide application of various synthetic polymer material products brings many pressures to the environment in which human beings rely on. In recent years, increasingly stringent regulations in the fields of global health, safety, and environmental protection require plastic products to be selected from materials, formulation components, processing technologies and processes, and use, as well as waste disposal, separation and recycling, recycling cycles, and environmental acceptability. Factors and factors such as the combustion products and their toxicity must consider the environmental load.
“Green†architectural plastics have become the development direction of the building materials industry in the 21st century. High-efficiency, multi-functionality, non-toxicity, and pollution-free are the general trends in the development of plastic auxiliaries. EU countries that use heavy metal lead salts stabilizers (such as France) have completed the technical reserves of the Ca/Zn thermal stability system and have promised to the EU that 50% of heavy metals will be replaced by 2010 and all will replace heavy metals by 2015.
The search for lead and cadmium alternatives has become increasingly urgent. At present, there have been a large number of highly cost-effective lanthanum/zinc, calcium/zinc compound stabilizers, rare earth heat stabilizers, and higher-priced organic tin stabilizers.
Flame-retardant polymer materials that use brominated biphenyl ether flame retardants are suspected to cause the release of carcinogenic substances such as benzodioxin and benzofuran when burning, and have also gradually warmed up the development of halogen-free flame retardants. PVC resin has a higher burning smoke and smoke suppression has become a key factor in improving the fire safety performance of PVC products. While developing flame retardants, the development of smoke suppressants is equally important.
Phenolic antioxidant BHT has low molecular weight, high volatility and extraction. In recent years, there has been a report of carcinogenicity. Vitamin E-based products have greatly eased the pressure of BHT. This series of products is a combination of vitamin E with phosphite, glycerol, polyethylene glycol, high porosity resin carrier components and other solids. Based on people's further awareness of health security and ecological protection, such "green" additives will have broad market potential and environmental protection value.
3. New additives on the basis of traditional additives, researchers based on the needs of functionality and economy, based on the basic theory, combined with the latest development of technological achievements, supplemented by a variety of processing technology, trial production of various A new type of additive. Compared with conventional auxiliaries, these auxiliaries have greatly improved the technical content and made a qualitative leap in performance; or they have become a new type of auxiliaries from scratch. All this has made the auxiliary industry present a trend of "opening flowers and contending with one hundred flowers."
3.1 crystal modifier (nucleating agent)
Mentioned crystal modifiers, people can easily think of nucleating agents, transparent agents, think of polypropylene nucleating agent. Nucleation transparent agent is only one of the crystal modifiers. Crystal modification is also not a patent for polypropylene. Where crystalline polymers can add crystal modifiers to adjust the crystallization behavior of the resin.
The crystal modifier is added to crystalline polymers such as polyethylene, polypropylene, polyamide, polyester, and polyether, changing the crystallization behavior of the resin, accelerating the crystallization rate, increasing the crystal density and promoting the refinement of the grain size, and shortening Molding cycle, or fully or partially improve the physical properties of products such as transparency, surface gloss, tensile strength, rigidity, heat distortion temperature, etc. Beijing Yanhua Resin Co., Ltd. uses rare earth crystal modifier WB G-4 as homopolymerization The performance comparison of propylene and polypropylene copolymers shows that both the impact strength and the heat distortion temperature have been significantly improved. The WXD diagram shows that after the addition of the rare earth crystal modifier WB G-4, the proportion of the beta crystal form of polypropylene accounts for more than 95% of the total crystalline fraction. Moreover, after multiple thermal history, the β crystal form ratio has not changed much.
At present, there are many research institutes engaged in the research of crystal modifiers at home and abroad. Many reports have reported that polypropylene β crystal nucleating agents, but it should be noted that the high percentage β crystals are commercially available. Where is the entry point.
It is an indisputable fact that the crystallization of polypropylene has become a research hotspot. However, the crystal modifier needed for engineering plastics is almost blank in China. Many foreign modified engineering plastics specifications clearly show that nucleating agents have been added, and most of the domestic engineering plastic resins still follow the habit of fiber-grade resins. Resins such as PET, PA6, and PA66 have almost no nucleating agent added. The synthesis and application of special crystal modifiers (nucleating agents) for engineering plastics (polyester, polyamide, etc.) are urgently to be developed.
Whether nucleating agents for polypropylene can be introduced into engineering plastics deserves further study. There are reports of relevant patents abroad, and few people in China are engaged in such research.
3.2 Surface treatment agent Fill modification is one of the important means for plastic modification. Rigidity and toughness are two important performance indicators of plastic products. How to ensure that plastic products have good rigidity and toughness at the same time is an important issue for material science research for a long time. one.
One of the key technologies for improving the effect of filling modification is the surface treatment technology of inorganic powders. The most widely used at present is the coupling agent activation technology. Coupling agents are available in a wide variety of industries and include coupling agents such as silanes, titanates, aluminates, aluminum-titanium complex esters, phosphate esters, and borate esters. Coupling agents are usually all amphiphilic substances, some of which are adsorbed on the surface of the filler or react with surface-bound water or -OH; other groups (or long chains) are entangled with the polymer matrix to increase the inorganic filler and The compatibility of the base material resin improves its dispersibility in the matrix and its interfacial adhesion. However, due to the short organic chain of the organic coupling agent and the small effect of the organic coupling agent on the matrix, the improvement of the mechanical properties of the material is limited, and it cannot meet the need for improvement in the improvement of product performance on the market and further reduction of costs. It is hoped that a novel structural coupling agent, in addition to maintaining the amphiphilic structure of the conventional coupling agent, can also bond, associate, or form other physical functions with the filler and the base resin with stronger binding force. The structural characteristics of rare earth elements can meet this demand.
Guangdong Wei Linna Company uses PVC and rare earth elements to synthesize a novel modifier with toughening coupling and multi-functional properties, and inorganic powder CaCO3, etc., through the "core-shell" packaging technology. Developed a new type of surface treatment agent. The product can be used as inorganic rigid particle toughening agent for PVC, with multi-functionality. It has a unique effect of improving the efficiency of PVC or PVC/CaCO3 filling system and has been applied in industry.
3.3 Grafted Polymers and Special Copolymers as Compatibilizers Polymer blending is the simplest and most convenient means of modifying materials. The compatibilizer is produced along with this process. The so-called compatibilizer is to enable the two resins blended to form a thermodynamically compatible state with the help of the process, thereby combining the advantages of several blended materials to achieve high performance and functionalization.
The compatibilizer is generally a grafted polymer or a special copolymer, that is, the two chemically diverse molecular segments are combined together by a chemical method. The greater the difference in molecular segment performance, the better the compatibility effect. Such as the polar maleic anhydride grafted on the polyolefin macromolecular chain, there is a good compatibility for PP / PA alloy. To date, polymer compatibilizers have been developed on the basis of the concept of surfactants. The main purpose is to adjust the microscopic phase structure of two or more polymer blends with different properties. The role of control to improve the performance of its materials, from the perspective of functional characteristics can be summarized as structural compatibilizers. At present, there are still some problems in the application of such compatibilizers, such as high preparation cost, low efficiency, and poor compatibility. Moreover, for some special polymer materials systems, no compatibilizer with good effect has been found so far.
In the future, the development of compatibilizers will inevitably aim to comprehensively meet and promote the rapid progress of polymer materials, from structural compatibilizers to functional compatibilizers, compatible compatibilizers, high-efficiency compatibilizers, and characteristic phases. Changes in the direction of the agent. In a broad sense, the scale of the composite (dispersion) phase that can be involved in polymer material preparation technology has moved from the micro-age to the nano-age, and the theory and practice of polymer molecular design, material properties and structural design, process design, etc. Progress will make the conversion of compatibilizers in the direction of development an inevitable historical factor.
3.4 Nano-powder/fiber powders The ultra-fine technology of inorganic powders derives two branches. One is the nano-size of inorganic powders, the other is the development of inorganic powders to the direction of reinforcing fibers.
A variety of nanotechnology has made the nanometerization of inorganic powders a reality, and the advent of various inorganic nanoparticle/polymer composites has made nanoinorganic powders enter the ranks of functional additives, and is no longer just superfine inorganic fillers. Agent.
The industrial production of magnesium salt whiskers and fibrous wollastonite has broadened the application fields and improved its own functions.
Prof. Qiong Zongneng of the Chinese Academy of Sciences prepared nanocomposites with high strength and heat resistance, high barrier and self-extinguishing properties, such as nylon 6-nanometer plastics and PET, using nano-inorganic phase material montmorillonite as filler material. Nano-plastics, ultra-high molecular weight polyethylene clay nanocomposites, nano-random copolymer polypropylene, nano-polyethylene high barrier films, etc., have been tested, performance is much higher than the general filling material, and some properties are extremely prominent. At present, some products have already achieved industrialization.
Prof. Huang Rui of Sichuan University prepared the polymer/nano-inorganic particle composites by melt blending method. Through the process research of polymer/elastomer/nano-inorganic particles in the ternary composite system, the "sandbag structure" toughening was proposed. The mechanism has verified that the toughening system conforms to the percolation law and quantifies the brittle-ductile transformation of the composite system.
4. Rare Earth Additives Become a New R&D Hot Spot Because of its special outer electron structure, rare earth elements have been used successfully for various special functions such as optical, electrical, magnetic and interface effects, shielding, and chemical reactivity. In the production of optical, electrical, magnetic materials and catalysts. After the rare earth elements were introduced into the structure of the polymeric materials, the efficacy of the additives has undergone a refreshing change.
In the 1990s, China first to commercialize rare earth compounds for PVC thermal stability. Because it not only has the function of thermal stabilizer, but also shows the coupling, processing modification, brightening and brightening and other functions, with a higher cost performance.
Rare earth compounds as PP crystal modifiers, as a rheological modifier of LLDPE, and as a surface treatment agent for inorganic particles, have unique functions, toughening and increasing rigidity of polyolefin, improving heat distortion temperature and improving Processing performance has a significant effect. Fluorescent properties of rare earth compounds have also been used to make luminescent plastics, magnetic rare earth materials have been used to make magnetic plastics, and light-emitting plastics have been made using the light conversion properties of rare earth compounds. Combining light rare earth compounds with traditional halogen-free flame retardants, the development of halogen-free rare earth flame retardants, and their application in polyolefins, can meet the requirements of flame retardant, while improving the comprehensive performance of flame-retardant materials, overcoming traditional inorganic non- Halogen flame retardants deteriorate the disadvantages of the physical-mechanical properties of flame retardant substrates.
In addition, rare earth modified master batches or special materials can be applied to various specific target products such as automobiles, home appliances, pipes, and the like.
5. Conclusions The development of any technology is inseparable from innovation. The technological improvement of traditional additives, the change of research and development ideas, and the constant emergence of new technologies and new theories have all brought vitality to our auxiliary industry. The self-confidence of China's auxiliaries and the level of catching up with the advanced developed countries are no longer a luxury. The emergence of new additives will surely make China's auxiliary industry enter a new era.
China's auxiliary industry started late, and development is slow, it is difficult to adapt to the current development trend, we must rely on the development of the industry to explore a path with additives with Chinese characteristics. Based on the digestion, absorption, and imitation of foreign advanced varieties and technologies, we have developed highly efficient, versatile, compound, low (no), low (no), and specialized additives for different industries. , To increase the scale of production and management capabilities, change the current small-scale additives industry, variety, performance, aging and similarity, targeted (dedicated) poor, performance-cost ratio is significantly lower than similar foreign products, low innovation capacity, serious pollution, The disorderly competition situation creates a new industry with a significantly higher input-to-output ratio than other chemical products.
2. Improvement of Traditional Additives 2.1 The purpose of composite compounding is to find an additive that makes it versatile and meets the needs of multiple functions. The new composite technology is based on the study of classical theory and applied technology, and combines additive components that show synergistic effects or different functions to form a composite or masterbatch, regardless of the development or application of additives. The fact that it has a multiplier effect is also an important reason why composite technology has attracted much attention.
The compounding of auxiliaries includes mixed auxiliaries and concentrated master batches. The former is a mixture of various additives, and the latter is attached to the carrier resin at a relatively high concentration of auxiliary agents, dispersants, etc., and diluted a certain number of times during processing. The common feature of composite technology is the simple and convenient application of additives. Therefore, the composite technology has penetrated into various fields of plastic additives. Compared with the earlier simple complex additives, the composite technology of contemporary additives has made a quantum leap, and the role of the synergistic components is very critical and outstanding. The study of the synergistic mechanism between the various components and the development of synergistic components will be the key to the development of auxiliary compounding technology in the future.
The Chemical Industry Research Institute of Beijing Municipality combined a high molecular weight hindered amine light stabilizer and a number of light and heat stabilizers with high thermal stability and metal ion chelating properties into a new BW-6911 light stabilizer. 6911/B215 anti-aging system. 6911 The use of special coupling technology to hold together hindered amine stabilizers of different structures not only reduces the migration rate of the light stabilizers in the resin, but also exerts the synergistic effect of the hindered amine stabilizers with different structures and increases the resistance. The ability of long-term high-temperature oxidative degradation effectively solves the problem of the cracking of the shed film at the frame of the greenhouse due to the “back plate effect†during the high temperature season. This is a problem that cannot be solved by the general anti-aging systems such as 622, 944 and GW540. 1,2]. The new composite antioxidants and GX2225 introduced by Ciba Specialty Chemicals are compounded by the introduction of the benzofuranone compound HP-136 into traditional composite antioxidants B215 and B225. HP-136 can capture the carbon radicals directly produced by polymer degradation and block the degradation chain reaction. The GX2215 allows polyolefins and other polymer materials to maintain excellent stability during high temperature processing.
2.2 Macromolecule Quantification The macromolecular quantification can improve the thermal stability, hydrolysis resistance of the auxiliaries themselves, increase the compatibility between the auxiliaries and the base resin, and improve the migration resistance and extraction resistance of the auxiliaries in the plastic products. Without excessively deteriorating the basic physical and mechanical properties of the substrate. High molecular weight is also an effective means to reduce the toxicity of the additives themselves. The high molecular weight antioxidant 1010 is significantly improved in hydrolysis resistance, migration resistance, and extraction resistance compared to the low molecular weight 1076. Polymeric antistatic agents provide permanent antistatic properties. High-molecular-weight flame retardants such as oligo-phosphonium bromide and oligo-phosphatidic acid esters significantly reduce the degree of deterioration of other basic physical and mechanical properties other than flame retardancy. The molecular weight of hindered amine light stabilizer (HAL S) can not only improve the thermal stability, compatibility with the resin, migration resistance, and extraction resistance, but also reduce the toxicity, prolong the service life of plastic products, and expand their use .
2.3 Environment-friendly The deep and wide application of various synthetic polymer material products brings many pressures to the environment in which human beings rely on. In recent years, increasingly stringent regulations in the fields of global health, safety, and environmental protection require plastic products to be selected from materials, formulation components, processing technologies and processes, and use, as well as waste disposal, separation and recycling, recycling cycles, and environmental acceptability. Factors and factors such as the combustion products and their toxicity must consider the environmental load.
“Green†architectural plastics have become the development direction of the building materials industry in the 21st century. High-efficiency, multi-functionality, non-toxicity, and pollution-free are the general trends in the development of plastic auxiliaries. EU countries that use heavy metal lead salts stabilizers (such as France) have completed the technical reserves of the Ca/Zn thermal stability system and have promised to the EU that 50% of heavy metals will be replaced by 2010 and all will replace heavy metals by 2015.
The search for lead and cadmium alternatives has become increasingly urgent. At present, there have been a large number of highly cost-effective lanthanum/zinc, calcium/zinc compound stabilizers, rare earth heat stabilizers, and higher-priced organic tin stabilizers.
Flame-retardant polymer materials that use brominated biphenyl ether flame retardants are suspected to cause the release of carcinogenic substances such as benzodioxin and benzofuran when burning, and have also gradually warmed up the development of halogen-free flame retardants. PVC resin has a higher burning smoke and smoke suppression has become a key factor in improving the fire safety performance of PVC products. While developing flame retardants, the development of smoke suppressants is equally important.
Phenolic antioxidant BHT has low molecular weight, high volatility and extraction. In recent years, there has been a report of carcinogenicity. Vitamin E-based products have greatly eased the pressure of BHT. This series of products is a combination of vitamin E with phosphite, glycerol, polyethylene glycol, high porosity resin carrier components and other solids. Based on people's further awareness of health security and ecological protection, such "green" additives will have broad market potential and environmental protection value.
3. New additives on the basis of traditional additives, researchers based on the needs of functionality and economy, based on the basic theory, combined with the latest development of technological achievements, supplemented by a variety of processing technology, trial production of various A new type of additive. Compared with conventional auxiliaries, these auxiliaries have greatly improved the technical content and made a qualitative leap in performance; or they have become a new type of auxiliaries from scratch. All this has made the auxiliary industry present a trend of "opening flowers and contending with one hundred flowers."
3.1 crystal modifier (nucleating agent)
Mentioned crystal modifiers, people can easily think of nucleating agents, transparent agents, think of polypropylene nucleating agent. Nucleation transparent agent is only one of the crystal modifiers. Crystal modification is also not a patent for polypropylene. Where crystalline polymers can add crystal modifiers to adjust the crystallization behavior of the resin.
The crystal modifier is added to crystalline polymers such as polyethylene, polypropylene, polyamide, polyester, and polyether, changing the crystallization behavior of the resin, accelerating the crystallization rate, increasing the crystal density and promoting the refinement of the grain size, and shortening Molding cycle, or fully or partially improve the physical properties of products such as transparency, surface gloss, tensile strength, rigidity, heat distortion temperature, etc. Beijing Yanhua Resin Co., Ltd. uses rare earth crystal modifier WB G-4 as homopolymerization The performance comparison of propylene and polypropylene copolymers shows that both the impact strength and the heat distortion temperature have been significantly improved. The WXD diagram shows that after the addition of the rare earth crystal modifier WB G-4, the proportion of the beta crystal form of polypropylene accounts for more than 95% of the total crystalline fraction. Moreover, after multiple thermal history, the β crystal form ratio has not changed much.
At present, there are many research institutes engaged in the research of crystal modifiers at home and abroad. Many reports have reported that polypropylene β crystal nucleating agents, but it should be noted that the high percentage β crystals are commercially available. Where is the entry point.
It is an indisputable fact that the crystallization of polypropylene has become a research hotspot. However, the crystal modifier needed for engineering plastics is almost blank in China. Many foreign modified engineering plastics specifications clearly show that nucleating agents have been added, and most of the domestic engineering plastic resins still follow the habit of fiber-grade resins. Resins such as PET, PA6, and PA66 have almost no nucleating agent added. The synthesis and application of special crystal modifiers (nucleating agents) for engineering plastics (polyester, polyamide, etc.) are urgently to be developed.
Whether nucleating agents for polypropylene can be introduced into engineering plastics deserves further study. There are reports of relevant patents abroad, and few people in China are engaged in such research.
3.2 Surface treatment agent Fill modification is one of the important means for plastic modification. Rigidity and toughness are two important performance indicators of plastic products. How to ensure that plastic products have good rigidity and toughness at the same time is an important issue for material science research for a long time. one.
One of the key technologies for improving the effect of filling modification is the surface treatment technology of inorganic powders. The most widely used at present is the coupling agent activation technology. Coupling agents are available in a wide variety of industries and include coupling agents such as silanes, titanates, aluminates, aluminum-titanium complex esters, phosphate esters, and borate esters. Coupling agents are usually all amphiphilic substances, some of which are adsorbed on the surface of the filler or react with surface-bound water or -OH; other groups (or long chains) are entangled with the polymer matrix to increase the inorganic filler and The compatibility of the base material resin improves its dispersibility in the matrix and its interfacial adhesion. However, due to the short organic chain of the organic coupling agent and the small effect of the organic coupling agent on the matrix, the improvement of the mechanical properties of the material is limited, and it cannot meet the need for improvement in the improvement of product performance on the market and further reduction of costs. It is hoped that a novel structural coupling agent, in addition to maintaining the amphiphilic structure of the conventional coupling agent, can also bond, associate, or form other physical functions with the filler and the base resin with stronger binding force. The structural characteristics of rare earth elements can meet this demand.
Guangdong Wei Linna Company uses PVC and rare earth elements to synthesize a novel modifier with toughening coupling and multi-functional properties, and inorganic powder CaCO3, etc., through the "core-shell" packaging technology. Developed a new type of surface treatment agent. The product can be used as inorganic rigid particle toughening agent for PVC, with multi-functionality. It has a unique effect of improving the efficiency of PVC or PVC/CaCO3 filling system and has been applied in industry.
3.3 Grafted Polymers and Special Copolymers as Compatibilizers Polymer blending is the simplest and most convenient means of modifying materials. The compatibilizer is produced along with this process. The so-called compatibilizer is to enable the two resins blended to form a thermodynamically compatible state with the help of the process, thereby combining the advantages of several blended materials to achieve high performance and functionalization.
The compatibilizer is generally a grafted polymer or a special copolymer, that is, the two chemically diverse molecular segments are combined together by a chemical method. The greater the difference in molecular segment performance, the better the compatibility effect. Such as the polar maleic anhydride grafted on the polyolefin macromolecular chain, there is a good compatibility for PP / PA alloy. To date, polymer compatibilizers have been developed on the basis of the concept of surfactants. The main purpose is to adjust the microscopic phase structure of two or more polymer blends with different properties. The role of control to improve the performance of its materials, from the perspective of functional characteristics can be summarized as structural compatibilizers. At present, there are still some problems in the application of such compatibilizers, such as high preparation cost, low efficiency, and poor compatibility. Moreover, for some special polymer materials systems, no compatibilizer with good effect has been found so far.
In the future, the development of compatibilizers will inevitably aim to comprehensively meet and promote the rapid progress of polymer materials, from structural compatibilizers to functional compatibilizers, compatible compatibilizers, high-efficiency compatibilizers, and characteristic phases. Changes in the direction of the agent. In a broad sense, the scale of the composite (dispersion) phase that can be involved in polymer material preparation technology has moved from the micro-age to the nano-age, and the theory and practice of polymer molecular design, material properties and structural design, process design, etc. Progress will make the conversion of compatibilizers in the direction of development an inevitable historical factor.
3.4 Nano-powder/fiber powders The ultra-fine technology of inorganic powders derives two branches. One is the nano-size of inorganic powders, the other is the development of inorganic powders to the direction of reinforcing fibers.
A variety of nanotechnology has made the nanometerization of inorganic powders a reality, and the advent of various inorganic nanoparticle/polymer composites has made nanoinorganic powders enter the ranks of functional additives, and is no longer just superfine inorganic fillers. Agent.
The industrial production of magnesium salt whiskers and fibrous wollastonite has broadened the application fields and improved its own functions.
Prof. Qiong Zongneng of the Chinese Academy of Sciences prepared nanocomposites with high strength and heat resistance, high barrier and self-extinguishing properties, such as nylon 6-nanometer plastics and PET, using nano-inorganic phase material montmorillonite as filler material. Nano-plastics, ultra-high molecular weight polyethylene clay nanocomposites, nano-random copolymer polypropylene, nano-polyethylene high barrier films, etc., have been tested, performance is much higher than the general filling material, and some properties are extremely prominent. At present, some products have already achieved industrialization.
Prof. Huang Rui of Sichuan University prepared the polymer/nano-inorganic particle composites by melt blending method. Through the process research of polymer/elastomer/nano-inorganic particles in the ternary composite system, the "sandbag structure" toughening was proposed. The mechanism has verified that the toughening system conforms to the percolation law and quantifies the brittle-ductile transformation of the composite system.
4. Rare Earth Additives Become a New R&D Hot Spot Because of its special outer electron structure, rare earth elements have been used successfully for various special functions such as optical, electrical, magnetic and interface effects, shielding, and chemical reactivity. In the production of optical, electrical, magnetic materials and catalysts. After the rare earth elements were introduced into the structure of the polymeric materials, the efficacy of the additives has undergone a refreshing change.
In the 1990s, China first to commercialize rare earth compounds for PVC thermal stability. Because it not only has the function of thermal stabilizer, but also shows the coupling, processing modification, brightening and brightening and other functions, with a higher cost performance.
Rare earth compounds as PP crystal modifiers, as a rheological modifier of LLDPE, and as a surface treatment agent for inorganic particles, have unique functions, toughening and increasing rigidity of polyolefin, improving heat distortion temperature and improving Processing performance has a significant effect. Fluorescent properties of rare earth compounds have also been used to make luminescent plastics, magnetic rare earth materials have been used to make magnetic plastics, and light-emitting plastics have been made using the light conversion properties of rare earth compounds. Combining light rare earth compounds with traditional halogen-free flame retardants, the development of halogen-free rare earth flame retardants, and their application in polyolefins, can meet the requirements of flame retardant, while improving the comprehensive performance of flame-retardant materials, overcoming traditional inorganic non- Halogen flame retardants deteriorate the disadvantages of the physical-mechanical properties of flame retardant substrates.
In addition, rare earth modified master batches or special materials can be applied to various specific target products such as automobiles, home appliances, pipes, and the like.
5. Conclusions The development of any technology is inseparable from innovation. The technological improvement of traditional additives, the change of research and development ideas, and the constant emergence of new technologies and new theories have all brought vitality to our auxiliary industry. The self-confidence of China's auxiliaries and the level of catching up with the advanced developed countries are no longer a luxury. The emergence of new additives will surely make China's auxiliary industry enter a new era.
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