Research progress of rare earth polymer composites Liu Li, Zhang Liqun. Jinguang School of Materials Science and Engineering, Beijing University of Chemical Technology, Beijing 100029, China The application can effectively compensate the weak absorption region of lead; the compound polymer shielding material with high rare earth content has strong thermal neutron absorption ability; the copolymer containing rare earth has strong Paramagnetic. The feasibility of preparing magnetic and magnetic intelligent rare-earth polymer composites was also proposed. In addition, three main preparation methods of rare-earth polymer composites were summarized. The polymerization method was simple blending method and reaction processing method. The effects of the structure and coordination number of rare earth precursor molecular coordination precursors on the optical properties were analyzed. The structure and characteristics of the ionomers that may be possessed by rare earth polymer composites were pointed out. The feasibility of in situ formation of rare earth polymer nanocomposites was proposed. The relationship between structure and properties of rare earth composites is also discussed in detail. The preparation of rare-earth polymer composite materials is described in detail. During the development of polymer materials science, people have not only satisfied with the inherent characteristics of polymer materials, but have paid more attention to the special properties. Such as resistance to high temperature and ultra-resistant aging high-strength super tough special electric properties and special features such as optical electromagnetic sound of special materials research and development. This material is highly recommended because it combines the advantages of high molecular weight, light weight, strength, ease of processing and corrosion resistance, and special properties. It is a new hot spot in the research and development of polymer materials, and can be called special financial resources. , It can be obtained by a variety of techniques including crystallization and blending processing, but comparatively speaking, it is simple and effective to compound a disperse phase material having a special function with a polymer matrix by a blending processing or a blending reaction processing technology. A flexible and economical technology, based on this technology, people have acquired a large number of special molecular composites.
Rare earths have optical and electromagnetic properties due to their unique electronic structure. These properties are the strong driving forces for the preparation of rare seven polymers and complex composite materials.
Out in 1963. The fluorescence and laser properties of Tributyltin Thiophene methyl fluorenyl fluoroacetone in poly(methyl methacrylate) opened up a new field of rare earth polymer research. Afterwards, scientists used rare-earth doping in polymer materials to obtain rare-earth polymer composites with unexpected properties such as photoelectromagnetic properties. In the 1980s, the research of polymers directly bonded to rare earths on the chains began to unfold, and certain achievements were made in the preparation of fluorescent laser and magnetic materials and optical plastic catalysts. If the ring is added during nylon polymerization, the acid shop can significantly reduce the content of ferrosilicon impurities with high degree of polymerization, the wear resistance of the product can be increased by 1 times, the heat resistance can be improved by 10%, and the tensile strength can be improved by 70. The performance of the gear slider seal gaskets and other properties are better than that of the non-thinning Puying nylon molecular materials, and the economic effect is remarkable. 3. The rare earth compound molecules found in the study of rare earths used for polyvinyl chloride and stabilizers 8 + With, swollen by system, 1 produces a strong coordination, differential scanning calorimetry 08, the results show that the rare earth is stable, the sample glass transition temperature is higher than the stability of cadmium stearate samples 3, theoretically rare earth can be It can be used as a non-toxic stabilizer for benzene, hydrazine, and humans, and can effectively solve the harm caused by lead, cadmium and other heavy metal stabilizers to the human environment. The agricultural plastic film modified by the rare earth stearic acid salt produced in China is not only high in strength, but also has good transparency; the fluorocarbon antimony can also be used as antimony to improve its thermal performance; and the rare earth-rich polyvinyl fluoride history 1 ion is added. With the keto-pyridyl thiol sulfonate-based macromolecular ligand, a rare-earth polymer luminescent material containing + or 3+ can be prepared. The former produces 6131 red fluorescence, and the latter emits a received date of 200023; 20010216 Fund Project Supported by the National Natural Science Foundation of China 5973008 The Journal of the Chinese Rare Earth Society 19
Methyl methacrylate, a composite material with a good shielding 1 special properties of rare earth polymer composites Rare earth used in luminescent materials research is quite extensive, and related patents and literature are also quite a lot. We focus on the magnetic properties of ray-shielding properties of rare earth polymer composites, and on this basis we tentatively explore the feasibility of the application of rare earths in molecular smart materials.
1.1 ray shielding performance of rare-earth polymer composites According to studies, the properties of 0.1 neutrons are added to Nafoil glass, but because the neodymium formed after absorption of neodymium does not have the ability to absorb neutrons, the shielding performance increases with absorption. Continuation and reduction of corpses is characteristic nature 1 of rare earth using rare earth. The rare earth is first coordinated with a double bond-containing organic substance having an addition reaction capability such as methyl propionate and methacrylic acid ester, and then the first monomer styrene is introduced into the copolymer. Made 5 pounds. Into a copolymer of several good thermal neutrons and light transmittance of 0.6, 2 25.881 resistance, radiation, the introduction of 258OCkg4jsj is to prepare rare earth polymer composite radiation protection material is a small mention 1.1.1 For rare earth polymer composites, traditional ray shielding performance, 1 shielding material has good absorption ability for energy between 88 and between 1340 and ray, but there is a particle absorption ability for the energy between 4088 and ray. Although the weak absorption of the weak area, referred to as the "abbreviation", is a composite material with good neutron shielding effect, its protection is not optimal, because the transparency of the composite material must also be taken into account when it is manufactured. A method for improving the amount of rare earths is proposed, so the amount of rare earths in the obtained rare earth molecular transparent composite material does not exceed 10.
We have increased the amount of rare earths to more than 50 when studying rare earth polymer composite shielding neutron radiation materials. It is considered that the ideal village material for shielding neutron radiation shields with poor energy spectrum contains not only lighter elements such as hydrogen and carbon, but also heavy elements, and more importantly, it should contain thermal neutron slow neutrons and neutron energy neutrons. The special absorption capacity was replaced by mixed lanthanide elements, 3 to compensate for the weak absorption zone of 1, and rare earth rubber composite materials were obtained, and a good shielding effect was achieved. The resulting composite shielding material had the same protection capability as lead products. Lower Density 1. This shielding effect depends on each element in the 1 lanthanide element, and its anti-layer absorption material name in many of Yuan Yuan Qin's thermal neutrons has a higher reaction cross section than that of the past thought of absorbing thermal neutrons. In the village, boron and cadmium are more than 10 times larger, and the reaction cross section to slow neutrons and neutrons is also many times higher than the latter. Even fast neutrons are much higher than cadmium, so we have studied The high dilute and allowable polymer 4 materials are the ideal materials for shielding neutron radiation.
Along with the increase in the atomic number of elements gradually, high, that is, gradually from 38.9 to. 63.31 are all in the ideal position to make up for the weak absorption zone; 2 because the absorption edge of different layers of different elements of the lanthanide element is not the same, its particle absorption covers almost all of the particles of the mixed lanthanide elements, and weak absorption of each element. Area.
Material density g.
Mass-thickness composite material 2.4 lead rubber is equivalent to a mass thickness of 0.5 nm1Pb of shielding material; relative value 1.1.2 rare earth is still a molecular composite material shielding neutron emission performance neutron radiation because it is not charged, has a very strong wear on the material 1.2 Magnetic properties of rare earth polymer composites and magnetic smart materials 1.2.1 The magnetic properties of rare earth polymer composites Magnetic materials can be obtained by adding magnetic materials to polymer materials, such as the magnetic properties of refrigerators in plastic products. Doors. The magnetic material used in the past is often barium ferrite. Since the theoretical maximum energy product is only 9.220è€µ3, the addition amount must reach 2030 times the weight fraction of the polymer material to have better magnetic effect. Such a large amount of magnetic material is added. The polymer material itself will lose a lot of good elastic softness and physical and mechanical properties, thereby losing the sealing performance and sealing life. Therefore, people are looking for corpse polymer materials. With the addition of new materials, dilute magnetic materials not only have several hundred times the theoretical energy product of barium ferrite, but also have coercivity derived from magnetocrystalline anisotropy. Compared with barium ferrites, which rely on the anisotropy of grain shape to obtain magnetic properties, it is theoretically feasible to extract magnetic materials more effectively. The olefinic copolymers of rare earth polymers have strong paramagnetism, and the ferromagnetic behavior of lanthanum-containing rare earth porphyrin polymers at low temperatures has provided a technique for the study of rare earth high-index composite magnetic materials. basis.
In addition, in polymer materials, the specific role of alloys or polymer gels with elastic memory effect or volume phase transition has been widely used by people. 9. If a large deformation of the elastic shape memory is required A good combination of secondary shrinkage materials. In the effective avoidance of magnetostriction caused by the destruction of materials under the premise.
Therefore, it is possible to prepare a functional polymer material with a rarex polymer magnetostrictive property. The author boldly envisages that the use of rare earths for excitation or demagnetization can absorb or release the heat of the original burial to obtain a wider range of heat-resistant or cold-resistant elastomer materials and environmentally-responsive elastomer materials.
1.2.2 Analysis of Magnetic Smart Materials for Rare Earth Polymer Composites Microspheres and nanosphere polymer materials that are capable of paying environmental perception and response and have function discovery capabilities are at the forefront of current research on smart polymer materials. People expect microspheres and nanospheres to be like living cells. This kind can be exchanged, and I convert the energy to suit. I am fierce to protect, micro-balls can reach between 100,1. The ball size can reach 10, the following. These microspheres and nanospheres can realize single-input multiple-response electromagnetic photothermal, multiple input multiple response functions. This is of great significance in the field of biotechnology. 9 Qiu Guangming 1M et al. used magnetic iron oxide colloidal particles as seed particles, and adopted an adsorptive swelling method to prepare homogeneous magnetic submicron grades by emulsion polymerization of styrene and other monomers. Molecular microspheres, microspheres with a particle size of 0.10.31. Whether it is possible to use magnetic rarefied particles instead of deuterated iron particles to produce new rare earth polymer composite microspheres remains to be tried.
The TEM images of the magnetic 3 complex microspheres suggest that the composite of rare earth materials and macromolecule materials can be manufactured with special optical materials under the precondition of ensuring a good compatible interface. 1 Park. Magnetism can. Magnetic magnetic light. Magneto-acoustic conversion function, and through the corresponding processing, can achieve intelligent induction adjustment of microspheres or nanospheres living space magical functional new composite materials.
2 Preparation method of rare earth polymer compound village material Similar to any composite material sample, in order to obtain the rare earth molecular composite material with strong physical and mechanical properties and specific mechanical and electrical properties, it is necessary to ensure strong interfacial adhesion and ideal dispersion structure size and dispersion. Especially in the case of high levels of dispersed phase. The preparation methods of rare earth polymer composite materials are summarised as follows: 2.1 Simple Blending Method This is the earliest application method for the combination of rare earth and polymer, and is a zero-dimensional composite method. The purpose of incorporating rare earths in polymer materials is to use the specificity of rare earths, and it is expected to obtain special composite materials with similar alloy properties. The doped rare earth forms include rare earth alloy rare earth inorganic compounds such as rare earth oxide hydroxides sulfides and the like rare earth organic compounds rare earth alkoxides rare earth fatty acid salts rare earths+saturated salts, etc. incorporated in simple blended rare earth polymer composites In the preparation process, the mortar is compounded with rare earth inorganic compounds and molecules, and the polymers used are all thermosetting resins or thermoplastic resins such as neodymium-shielded neutron shielding composites with high translucency. We studied the compounding of rare earth and elastomeric thermoplastic elastomers and thermosetting elastomers. The obtained rare earth natural rubber composites and rare earth polyurethane thermoplastic elastomer composites not only have excellent physical and mechanical properties, but also have good elasticity. 2. Excellent neutron shielding ability, thermal neutron transmission rate of 43. The amount of rare earth doping is much greater than the amount of rare earth proposed. It is clear that the radiation shielding material prepared by compounding the rare earth and the elastic polymer material is more suitable for the application in the fixed place and obtaining the soft material, such as the medical ray against Shanghai clothing.
Material Shore hardness Tear strength MPa Elongation at break Composite materials Lead plastics Lead rubbers Simple blending methods Process image preparation is low but the disadvantages are often caused by mortal bodies and molecular materials. The large difference in variability makes it difficult to ensure a good balance between the two-phase interfaces of composite materials. The use of rare earths is greatly limited, and the performance degradation of materials can be improved by adding rare earth organic compounds, but it can also be fundamentally solved. 2.2 Polymerization method Polymerization of rare earths and polymer materials The research is from the people to obtain excellent light transmission performance of the rarefied. Polymer ligands are coordinated on the polymer chain with ligands in the starting chain. These ligands are mainly pyridoxaline crown ether groups and cryptand ether groups of ketocarboxylic acid sulfonates. The resulting ligand is further polymerized or added to another monomer to pulverize to obtain a homopolymerization high molecular weight and copolymerization macromolecule; 2 homopolymerization or copolymerization of a macromolecule is dissolved in a solvent, a corresponding rare earth compound is added, and rare earth ions are utilized The coordination ability and the leaving bond energy 9 produce homo- or copolymers containing rare earths under defined reaction conditions.
The use of these two methods to prepare different rare-earth polymer composite light-emitting village material, Sanda, Zhongshan, Khan, Lian Hui, Wang Hong, et al. Proved that the fluorescence properties of the co-polymeric composite materials obtained by these two methods are inconsistently not obtained by the fluorescence of the composite village material. The intensity increases with the content of rare earth, plus linear, plus, while the fluorescence of the composite material obtained by the method 1 has a concentration of annihilation. 4 and others found that the fluorescence properties of the homopolymer system obtained by the above two methods all follow the content of rare earth ions. Increased linearly.
It has also been demonstrated that the effect of ion spacing and the clustering of ions formed by the formation of multiple ion pairs by Coulomb forces indicates that energy transfer occurs between the same species of rare earth ions when the metal ion spacing is sufficiently small. Resulting rare earth fluorescence concentration, extinction, 2.3 reaction processing method This is a new method for preparation of rare earth molecular composite materials proposed by the author. As mentioned above, the special physicochemical properties of dilute compounds have given it certain functional groups with macromolecules. The ability of coordination reactions and ionic bonding reactions, both reactions can exist simultaneously, which mainly depends on the structure and reaction conditions of the macromolecules.
This feature is not available in many polymer-filled reinforcing agents.
Therefore, if you use a functional polymer that has a strong chemical bond with rare earths as a boundary bond! Bonding agent achieves ideal dispersion in rare earth particles and functional high-functionality rubber melt blends under high temperature and high shear conditions, and then achieves cross-linking between functional rubber and non-functional rubbers during cross-linking molding process Therefore, it is possible to prepare rare-earth compound complex media with excellent overall performance. This kind of village material and preparation technology can be called; can be used as a macro-bonding bond or a combination of ionic bonding reaction, and we use the pre-made MMARE or MMA and only join at the same time. The process is carried out by blending reaction with mercaptonitrile nitrile milk 8 on a high-temperature processing facility, and then the rare earth-containing composite material, the rare earth compound, is raised to a level of 5 or more. It can be said that the reaction processing method is still at the stage of exploration, there are still many questions, such as the reaction ability of the two phases of composite materials. Strongly depends on the type and amount of rare earth disperse phase of the plant, the functional type of the functional polymer, the functional molecular weight and the distribution structure and the amount, the ratio of the non-functional polymer type and the compatibility between the structure and the functional rubber, also It is strongly influenced by reaction processing equipment parameters, force, and conditions, temperature, shear force, and material contact time.
(3) Research on the relationship among structure, structure and properties of rare earth polymer composite materials Based on the preparation method of rare earth polymer composite materials, the structure of composite materials is divided into composite precursor structure and composite material structure.
31. Rare-earth local molecules, precursor structures of composite materials In the study of light properties, we synthesized a 3-keto polymer neodymium complex by introducing a ketone into a polymer chain. The structure is as follows: 2 The steric hindrance of structure 1 is relatively large. The coordination can be formed at most, and the steric hindrance of the structure is smaller than that of the structure 1, so the coordination is formed. If the first-combined fluorene-containing structure 1 monomer is first synthesized and then copolymerized with styrene, then the hydrazine content is added. The coordination unit in the copolymer chain is increased, and the fluorescence is linear. Therefore, it is believed that the high coordination number of rare earth ions is a prerequisite for obtaining a good fluorescence enthalpy energy composite. 32. Structure of rare earth polymer composites 3.2.1 Ionomer structure And its effect on the performance of the rare earth polymer complex in the rare seven away from them and their; polymediary between the existence of multiple ion pairs and composed of ion clusters, so with the characteristics of ionomer. 014 et al. found that the styrenated styrene, acid copolymer, and (4) composite systems were converted from the structure of the plant (1) to the energy transfer of the ore. Increased the amount of disaster by 30 times. However, in the few and 0, 2+ composite systems of styrene-acrylic copolymers, rare-earth ions are transferred in 3+ direction and + energy, which leads to the decrease of the fluorescence intensity of the composites. However, this energy level matching is only a necessary condition to be able to transfer. The presence of the ion cluster structure in the chelating material is the prerequisite for energy transfer between the metal ions. In 990, there were many pairs of passenger-heavy ions in the ionomer cluster model of Tunxi 161. It is equivalent to a fire size cross-link point. Limit the chain movement of polymer in the factory. With higher ion concentration, the regions where these molecular chain movements are restricted overlap with each other to form a domain of tens of nanometers in size containing both the ions and the restricted polymer chains. Called Gurder 3. Ionic clusters have a direct effect on the performance of dilute one-component composites. If one finds the presence of ionized helium, the metal ion spacing is often smaller than the multipole moment interaction distance, and energy transfer occurs. So that changes in the degree of fluorescence. Ming Ming 17 discovered that the fluorination of perfluorosulfonate, domain cobalt, increased the fluorescence intensity of the composite material to 130, which was explained by the expansion of ion clusters upon heating, and the corresponding ion spacing extended beyond the multipole interaction distance of 1.54. The result of the decline in energy transfer efficiency. This progress confirms the presence of ion clusters in dilute molecular complexes. It should be pointed out that in the homopolymerization system, the rare earth ions are uniformly dispersed and there is no ion accumulation area, so no energy transfer occurs.
In other words, we hope to obtain this kind of ion cluster structure so that the influence of harmful rays can be absorbed or attenuated by energy transfer. Of course, this requires experimentation and confirmation of the present.
3.2.2 Structure and Properties of Diluted 1 Micronized Ultrafine Powders Molecular Inclusion Materials Liu Jingjiang et al. found that the addition of rare earth oxides with a fractional ultrafine powder of less than 1 in isotactic polypropylene can greatly increase the mechanical properties of the history. On this basis, Ye Chunmin 1 found that the orphaned pair had obvious nucleation and produced multiple crystal forms. Comparing the 2,3 isothermal crystallizations of 1 and oxytetraethylene powders,4 it was confirmed that only spherulites existed in 2 while there were distinct single dispersed spherulites in 151. It is pointed out that only 0 micron powder is different from the general inorganic filler, which can make the spherulite volume shrink to 164 with a wide range of crystalline phase amorphous phase interface, indicating that Choi has a significant effect on the performance of crystalline polymers.
3.3 In-situ generation of rare-earth polymer nanocomposite research prospects In 1998, the University of Pennsylvania's 2 others used simultaneous loading. Ring type field field 21 will be dry. 3; Old and bright field 5 Dressed up as a gentleman 1 Scintillation detector scanning TEM 0 Observed directly in the ionic aggregates in the ethylene methacrylic acid copolymer zinc salt. The ionic aggregates are approximately spherical. The diameter is between 2.52.8. In addition, when the content of 71 increases from 22 to 58, the number of ion aggregates is basically constant. This is inconsistent with the theory that the volume of ion aggregates will increase as the ion content increases in the Ra 13 model. Therefore, this 1I1 squat journal Khan provides a proof of practice for the application of metal ions.
Before this. 4, and 1 Hill 1 edition 3 et al. The yttrium methacrylate 70 and a free radical initiator were directly mixed in by a blending process, and were in-situ polymerization in the hall. In order to obtain excellent performance of 21 rubber nanocomposites. This undoubtedly provided a powerful inspiration for the preparation of rare earth polymer nanocomposites.
They will sigh 1 that the formation process of nanoparticles in the clothes is described as 7 and 6 that by dispersing the arts and crafts in 1 cents, this part of the body spreads to the rubber matrix and reaches the saturation state; Oxidation-initiated monomer polymerization to form 7171 has poor compatibility with the matrix, precipitating from the rubber matrix, and polyfluorene to generate S0 nanoparticles.
At the same time, the concentration of monomer 2 in the matrix gel is reduced by the polymerization.
Destruction of diffusion balance, so that 1 monomer can be transferred from the 7 1 to the matrix adhesive to ensure the progress of in-situ polymerization, in addition 33, the monomer will also occur with rubber macromolecule cross-linking and grafting reaction. Observe the phenomenon, phase, and position of the primary particles in the field where the sighs of the primary particles of the sigh 0 are gathered from a few to several nanometers. Yuan Xinheng 124 blends Level 1 and Level 7 into one level of knowledge. Through the appropriate early dynamic reaction processing. After cross-linking, the same or even better results were obtained.
Over the above analysis. The above-mentioned reaction processing method proposed on the sheet is an effective method for preparing a rare earth macromolecule in-situ polymerization nanocomposite material by using a rare earth organic salt. In addition to its characteristic of greatly increasing the amount of rare earths, another important advantage is that the process is very close to the traditional polymer processing technology, organic dilute salt monomer. The nanocomposite material can be obtained from the base initiator through mixing and direct in-situ acrylic acid metal salt, which facilitates the industrialization of the technology using existing equipment.
However, the use of rare earths to develop special applications of rare earth polymer composites, there are still many applications, some of which have been made in the prestigious statement, there is even more to ask is the rare earth particles for polymer degradation. It is the key to the mechanical properties of materials. Because in terms of composite materials, not only its specificity is needed. It should also have good mechanical properties. This is the premise of the use of materials. Therefore, during the research of rare earth polymer composite materials, the above issues should not be ignored.
In short, the optical properties of rare earth polymer composites prepared by the simple blending method have been studied extensively.
However, many special features of Levity 10 are not yet in place, and 5 points are reflected in He Village. In addition, the lack of mechanism research and processing methods alone have restricted the development and application of rare earth polymer composite materials. Therefore, we look forward to the emergence of newer rare earth polymer composite materials with better specific energy, and we look forward to this. The preparation of composite materials can have more technical means Xu Guangxian. Rare earth. Version 2. Beijing Zhijin Industry Press, 1995.
Yang Yuchun. Rare earth talk. Beijing Chemical Industry Press, 1999.
9 Yao Kangde. Smart material. Tianjin University Press, 1995.
Mixed, the island Sisi 4, Luan Jianyao squatters, 14 plus ignorance thoughts to run away, Teng Yu, Wang Lianhui. Synthesis and photomagnetic properties of rare earth metal complexes and their macromolecules å®„13. Zhejiang University, Hangzhou, 1997.
Wang Hongyu, Li Zhian, Song Guizhen, et al. The physical and chemical properties of the ionomer. Polymer Materials and Engineering, 199432730.
18 Liu Jingjiang, Tang Gongben, Zhou Huarong, et al. Ultramicro Oxidation - filled Polypropylene Thermostatic Crystallization Kinetics Applied Chemistry, 1998314.
2, Ye Chunmin, Liu Jingjiang, Tang Gongben. The microcrystalline yttria-filled polypropylene crystallizes. Plastics Industry, 1994 2 Yan Yuanxin, Peng Zonglin, Zhang Yong, et al. Enhanced zinc salt of unsaturated carboxylic acid. Synthetic Rubber Industry, 2000233173
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