Application of polymer liquid crystals

Key to polymer liquid products. development of. The same as the Chinese-French classification No. 050 liquid crystal is the intermediate state between the liquid state and the crystalline state. It has both the easy flow characteristics of the liquid and some characteristics of the product. Liquids prepared for homogeneity are transparent, while liquid crystals are often turbid. This is also a major feature of liquid crystals that distinguish them from isotropic liquids. The reason why the liquid crystal is mixed pool is caused by the fluctuation of liquid crystal 1 and caused by light. Liquid light scattering is 1 million times stronger than isotropic liquid. The polymer liquid product is formed by bonding relatively small molecular molecules, liquid crystal elements, and these liquid crystal elements may be rod-shaped; they may also be shaped; or they may be more complex and even dimensional shapes; or even both. Both can also be amphiphilic.

0. 4 The same phenomenon was observed. Since then, many people have made important contributions to the research and development of liquid crystals. The corpse established the definition and classification of liquid crystals, that is, liquid crystals are substances that collect liquids and crystals. Si 1613 et al developed the theory of birefringence of liquid crystals = 1. The theory of phase states of 7 liquid sophisticates was studied. In 19567 its well-known lattice theory was used to treat the lyotropic polymer system9, and the appearance of the liquid crystal phase of the rigid or semi-rigid polymer solution W; Uji; jlM.niUCAmlios1jtM acid methyl ester and polyglutamic acid was deduced. The benzyl ester IIUI was observed by yang stomach. It was found that in the aprotic solvents, such as hexachloromethane and other lyotropic liquid crystals, the International Conference on Liquid Crystals was held in 1965. Especially Tim. 8,1 and the river. Spit found that the twisted electro-optical effect of liquid crystals matched with integrated circuits made liquid crystal research extremely versatile and laid the foundation for a new emerging LCD industry system, and also promoted the fundamental theoretical research of liquid crystals. Shortly afterwards, the research and development of liquid crystalline polymer fiber 61 developed by the company of the United States and the United States succeeded in pushing the research of polymer liquid crystals to a climax 13.

Since the 1990s, research on liquid crystal phenomena, and the research report on the electronic strategy of liquid crystal materials, the research of high-definition color liquid crystal display devices has been listed as a key project. 13. The 1991 Nobel Prize in Physics; To give the most business evaluation of the scientific domain.

Reflects the world's scientific community's interest in liquid crystal research.

At the same time, since the 1990s, side-chain polymer liquid crystals have been found in many applications, such as the semi-flexible chain theory that has been gradually formed in recent years in optical information storage such as nonlinear optics and chromatography, and can handle various semi-flexible chains. The liquid crystal polymer, Wang Xinjiu In the theory, in summary, the liquid crystal science has obtained many important developments. The research field has spread throughout the various disciplines of physical chemistry and electronics biology, and has developed into liquid crystal chemistry molecular physics. Biological liquid crystal and liquid crystal molecular spectroscopy and other important subjects.

1 Liquid crystals, molecular germanium thousands of dimensions as a fiber material, require the highest possible tensile strength and modulus along the fiber axis. Theoretical calculations indicate that the maximum tensile modulus and tensile strength can be obtained if the polymer molecules that make up the fiber have a sufficiently high relative molecular mass and all are oriented along the axial direction of the fiber. Crystalline polymer fibers generally have a crystalline amorphous two-phase structure in which the crystalline structure is generally a lamellae formed by folding molecular chains, and even if it is stretched, it is difficult to achieve a relatively perfect axial orientation. Many structural defects and weak links have poor mechanical properties. The liquid crystal polymer is different under appropriate conditions. The liquid crystal molecules have a tilt that is automatically oriented along the long axis of the molecule. The viscosity coefficient of the system is also now anisotropic, and the viscosity coefficient along the long axis of the molecule is much smaller than in other directions, so that it is easy to form a highly oriented structure along the fiber axis in the spinning process to obtain excellent and industrialized Liquid crystal polymer fiber produced. Its high strength and high modulus and excellent heat resistance make it play an important role in the protection of materials, protective clothing, fire-retardant high temperature filtration.

Fiber tensile modulus 4 Asahi, Tensile strength 103 æ±¹ This linear high molecular liquid crystal high-fraction aramid 49 polyarylate gel-spun polyethylene nylon 66 polyester However, the scientific development is endless, in the theoretical research and practice of liquid crystal On the basis of continuous improvement, people are more courageous in designing and manufacturing new materials that have higher strength and modulus, and even close to theoretical extremes.

The victory of the family with outstanding mechanical performance and heat resistance in the state of 2 and 50. It is the most successful example of liquid crystal polymer engineering. If the invention of aramid is still accidental, the invention of the polyaromatic heterocycle liquid crystal polymer is entirely the result of careful planning and careful molecular design. The aromatic heterocyclic polymer polybenzimidazole 81 that has been discovered has good heat resistance, but its mechanical properties are similar. Then in 1977, the Air Force Aerospace Laboratory introduced a high-strength, high-modulus, high-temperature polybenzothiazole fiber. At the same time, at the same time, they also carried out research on polybenzoxazole 80. Unfortunately, Lee, the pioneer of 60, was not personally acquired, and the 80's final success. 0 after the 1990s, Jiechi Chemical Company cooperated with Toyobo. Successfully produced liquid helium 15, fiber. And with the product name of 1. to launch 2. With a score of excellent performance. Where there are 2 times the strength and mold of the batch is about 5.81 and 3001 respectively, the thermal decomposition temperature reaches 650, the gray warehouse swept the apricot shoots swollen and frequent rose, the fiber can get the performance of liquid crystal polymer with close to the theoretical extreme value. Nematic phase ordinary polymer random coil thermotropic polymer liquid crystal plastics Since aramid and aromatic heterocyclic liquid crystal polymers are lyotropic, that can not be adopted melt extrusion processing method, so in the high The application of Tantalum Plastics is limited. The thermotropic liquid crystal polymers based on aromatic polyester liquid crystal macromolecules compensate for the shortcomings of the highly soluble liquid crystal polymers. Currently, thermodynamic liquid crystal polymer polycargo boats that have been commercialized are roughly divided into three types. Types of. Ie the father of 4 companies. And 9 companies, 3 generations of the type and the 1 to 1 company molecule and the station component of the paraben for the parabens out 8.4.4.

Phenol (1) and various ratios of p-benzoic acid (3) (1) and m-benzoic acid; naphthalene series, main components are 6 and 6 hydroxyl 2 naphthalene fusible, homogeneous comonomer products, type 1 heat resistance is best, suitable for Where high temperature performance is required, but processing is more difficult; hot and cold properties are poor; overall performance of the type is good, and heat resistance is medium (1).

The liquid crystal is high, the chain structure is non-liquid product, and I am researching and researching Kun. The coordinating ligand's highly oriented stretched chain structure along the orientation direction has lower mechanical properties of the platelet structure. As a result, the polymers 601 are 1 and the old seven-order copolyesters are nematic liquid crystals. The processing test shows that the copolyester has excellent processing fluidity, and its mechanical properties, heat resistance and electrical insulation meet or exceed the level of similar foreign products, in which the tensile strength exceeds 03, and the thermal expansion coefficient is close to the value of ceramics. Two unique properties exhibited the wide application prospects of this liquid crystal copolyester as an engineering plastic.

In addition, the report also reported that the main method for the conversion of eutectic polyurethane elastomers 17 is to introduce a liquid product base in a multi-block polyurethane cooling plant, and to use polarized light from a micromirror and an archaic polymer to measure the viscosity of the polymer. The two-phase structure of the chemical structure and the effect of hydrogen bonding on the formation of the liquid crystal state revealed that most of the polyurethane samples exhibited a nematic liquid crystal phase transition, and the properties of the thermoplastic elastomer of the pharynx were exhibited by many people. The uniaxial tensile analysis shows that the liquid crystal polyurethane has two kinds of orientation mechanisms, and the sample has good mechanical strength and film forming ability.

Polymer liquids are particularly suitable for high-performance engineering materials due to their excellent mechanical properties such as high modulus and high strength. For example, a polymer liquid crystal is used as an excellent surface connecting material for directly fixing electronic components to a printed circuit board surface.

In addition, the large-diameter polymer liquid crystal rod is also a candidate material for the replacement of construction steel bars. Compared with the steel bars, it has a good quality of light toughness, corrosion resistance and internal stress caused by temperature changes. The low viscosity and high strength properties of polymer liquid crystals have also been applied as additives for coatings. The viscosity of paints producing high-quality liquid crystals decreased. Flash can use less lotion. To reduce pollution. cut costs. After adding high-degradation nights, the strength of the paint after film formation is also large, plus 18.

3Liquid crystal to molecular composite liquid crystal polymer The formation of microfiber structure and good with the matrix material can be improved by adding a compatibilizer. The former is affected by various factors, such as the processing process of liquid crystal type liquid crystal content.

Chen Jianding et al.22 used a synthetic liquid crystal copolyester 3 ratio and (1) made Jiangfen, with different ratios and poly carbonate buttons, poly butyl benzoate 810 for in-situ compounding, in situ composite crystal copolyester The matching relationship with the matrix was evaluated for the effect of in-situ compounding.

Zhang Hongfang et al.23 use you. 1 and other methods studied the structure and energy of 70 pounds of 1 in-situ composite material, knot dyeing, when 7, kg 120, 170 can play an accelerated nucleation effect, redundant 70 and 1 part compatible, in comparison 70 The content of the material 3, observed that there is a clear skin core structure.

In recent years, there have been many reports on the research of liquid crystal polymers that are composited with matrix polymer molecules through interpenetrating polymer networks.

Mi Jun et al. used this kind of semi-interpenetrating polymer network based on a certain degree of copolymerization of a thermotropic liquid crystal polyester imide 031 containing a flexible segment and benzene methanebisinimide 8 leave. The liquid crystal polyesterimides were divided into three groups by thermal analysis, micro-analysis of orthogonal polarization stations, and electron microscopy of a billion-section electron microscope. It was found that the two couples have very good compatibility. The phantom is evenly dispersed in the crosslinked network structure. The dimensional crosslinked network structure restricts the motion of 01, fixes the phase texture of the liquid crystal, and does not phase separate during heating, and a molecular composite with thermosetting properties is obtained.

Totally profitable. 3,1; human 25 to pay benzoic acid as a substrate, through the free radical polymerization in the benzoic acid matrix composite acrylonitrile group can be made to obtain a cross-linked liquid crystal network, and by heat treatment can obtain a stable macro-orientation.

The liquid crystal high score+composite material is a thermotropic liquid crystal polymer as a reinforcing agent, and it is dispersed in the household matrix polymer by an appropriate method.

In-situ formation of microfiber structures achieves the purpose of mechanical properties of strong matrices.

Commonly used as a reinforcing material for liquid crystal polymer bet 7 he, 7 full-aromatic polyester and so on.

Maleic anhydride grafted perspiration was used as a compatibilizer to prepare a liquid crystal reinforced composite material. Its tensile strength and bending elastic modulus elongation at break were larger than pure. 12 et al., 6 others as enhancers. 4 1 blending, using the mechanical properties of the system obtained by the incorporation of ethylene methacrylic acid glycidyl methacrylate as a compatibilizer, including a large amplitude of the impact strength of 4 liquid crystals, the molecular branching material organic crushed polymer with its good heat The stability and wide liquid range have been used for a long time as a stationary phase in gas-liquid chromatography, such as polymethyl laurate, and polymethyl phenyl laurate, which are the famous 3 and 0 series stationary phases, respectively. When the liquid crystal material is added to the above stationary phase, it becomes a molecularly ordered stationary phase. The ordering of the molecules in the stationary phase is similar to the separation of boiling points and polarities, but the mixture of different structures has a better separation effect, due to the spatial arrangement of the liquid crystal material, and the ordering of the liquid crystal is involved in the separation process. The liquid crystal stationary phase is chromatographic, Personnel focus on the development of ancient deduction. 42,14. This is a 00 coffee 6 gamma also. Life 15 Jun 3. Use Gui for her. The four sounds are used alone as a stationary phase, and the macromolecularization of the small molecule liquid crystals overcomes the unit, and the orientation is easily achieved under the action of an external electric field, and the small molecule liquid crystals are easily lost under high temperature conditions. The problems that need to be solved when using a polymer liquid crystal as a chromatographic stationary phase include reducing the glass transition temperature of the polymer and broadening the temperature range of the liquid crystal state.

The introduction of chiral liquid crystals provides a very good separation tool for the separation of optical isomers.

With the adoption of cross-linking and other means, the polymer liquid crystal stationary phase is widely used in capillary gas chromatography and supercritical fluid chromatography and high-performance liquid chromatography. 5 Liquid Crystalline Polymer Information Materials 5.1 Liquid Crystal Polymers in Electrical Applications Polymer Liquids The ability of the product to change from unordered transparent state to ordered non-transparent state under the action of the tune field can also be applied to the production of display devices. It uses nematic liquid crystals placed between transparent electrodes under the action of an electric field. When a voltage is applied, it is crystallized by an electric field. When the ordered portion loses transparency, it produces the same artifact as the electrode. According to this principle, a display device such as a digital display, an electro-optic shutter billboard, and a television screen is made.

5.2 Application of Liquid Crystal Polymers in Information Storage Mediums and Optics Liquid mats produce non-linear optical materials that are particularly promising for side chain type liquid crystal polymers because of the high number of these polymers, which are introduced in sub-broadband. Highly polarizable and non-linear optically active liquid crystal forming and other distinguishing features such as Xie 27 of the Institute of Chemistry, Chinese Academy of Sciences synthesized several functional trapezoidal polysiloxanes with liquid crystalline features, including 3-ketoskrine azo Types of liquid crystal side chain fishbone liquid crystal polymers and corresponding complex-type liquid crystal polymers, as well as non-linear light trapezoidal macromolecules attached to chromophores, such negative bone-shaped liquid product molecules and small molecule liquid products The polarization-induced orientation of the polarizing film of the high-dimensional, wide-area network solution and the interesting trapezoidal macromolecule has now been developed.

Another promising liquid crystal polymer in information science is the dissociation of ferroelectric liquid products, some liquid crystal polymers containing chiral centers, and the formation of hand-made liquid products such as 3,815, etc. These aggregates satisfy iron. Electrical requirements for symmetry of molecules and materials are all ferroelectric. Potential applications for ferroelectric liquid crystal molecules include explicit device information transfer pyroelectric detection and nonlinear optical devices.

Liquid crystals can also be applied to light-guiding liquid crystal polymers. Photoconductors are substances that change their conductivity significantly under the irradiation of light. Germanium is a well-known photoconductive active substance, and polymers containing side chains of carbazole are also photoconductive. Examples 2 are polyvinyl carbazole 3,6-bromo-polyvinyl carbazole and poly(ethylene-ethylene-diethyl ether), etc. . In the dark, they are insulators but under UV light their electrical conductivity increases significantly. Polyvinyl carbazole has been used in electrophotography and xerography, and can also be used as a total record in combination with a thermoplastic film. Material, polyvinyl carbazole poly 6 did not replace polyethylene ethane 2 ethylene, vinyl hydrazine 6 liquid crystal, molecular month, cell detachment is an important part of the cell, it plays a role in separating the external environment from the internal environment. effect. In order for ions to diffuse through and let the gas exchange inside and outside, the cell membrane should have a selective function.

The cell membrane is a diterpene molecule composed of quinones and proteins. It is composed of phospholipids and sterols and is opened into a bilayer. Its chemical structure is the same. The protein molecules are adsorbed on the hydrophilic groups to form two proteins on the top and bottom, which is actually 1; the small similar phase structure.

In addition, the important structural part of the cell membrane, chitin and nuclei in the cell nucleus, is substantially a cholesteric liquid crystal phase, and a composite membrane composed of a polymer and a low molecular liquid crystal can also have selective bleed. Transparency, which is widely used in many industrial fields. For example, ion exchange membrane test rich 1 sit; charge separation membrane desalting membrane. People have constant intensity, good permeability, and have obvious response to electric field and even to solution value.

The polymer material polycarbonate 0 and the small molecule liquid crystal 4 ethanediyl benzylidene p-aminobutyl group (1) (1) The heart can be used for gas separation by making the compound expansion ratio as (4). In the liquid crystal phase, gas permeability is greatly enhanced. Furthermore, the selective control of the external electric field applied to the above-mentioned laminated film will change the arrangement direction of the liquid crystal polymer, thus changing the gas permeability, and when such a composite film is provided, it can also efficiently separate or enrich the mixed gas. A component 31 high-molecular-weight polymer liquid crystal crown ether composite film under ultraviolet and light irradiation, gold, ion 1 will be diffused, the complex function of this membrane can be used for artificial kidney and environmental protection 323.

Peripheral, such as the use of factory-rubber styrene-butadiene rubber and polyethylene with 012 = 01 end group of liquid crystal compound blending, solution casting method into the rubber liquid crystal composite film using 3202 vapor cross-linked. The volumetric method was used to determine the gas permeability of the membrane. The influence of different matrix materials and different liquid crystal types on gas separation performance was emphatically studied. As a result, the air permeability coefficient of the liquid film made by BD Rubber was the highest. The separation performance is also best = the water-soluble part is insoluble in the water part. In summary, the liquid crystal polymer is distinguished from other polymer materials by its dielectric optical and mechanical properties, and its chemical resistance is low. Combustibility and excellent The dimensional stability, it is increasingly valued in many areas, has been more and more widely used = 13 National Natural Science Foundation of China. Optics and optoelectronics. Beijing Science Press, 14 Zhang Jinjin. Introduction to Polymeric Liquid Crystals. Anhui University of Science and Technology Press, 1994 15 Shi Lianghe, Hu Hanjie. Polymer Science Today and Tomorrow. Beijing Chemical Industry published 16 Hong Ding. Lü Zhanxia, ​​Ma Yunqian, et al. The synthesis and properties of the thermotropic liquid crystal 1 is similar to the 601 centimeter copolyester. Synthetic resins and plastics 1995,3;3 17 Yu Xuehai. Research on Liquid Crystalline Polyurethane Elastomers. Proceedings of National Conference on Polymer Academic Papers, Anhui, 1997 18 Zhao Wenyuan, Wang Yijun. Functional polymer materials chemistry. Beijing Chemical Industry Press, 19 Li Jinchun. 1 and 71 out of 8 blended liquid crystal reinforced composites. Engineering Plastics Application, 1997, 2512 21 Pak. Polymer alloys. Shanghai Tongji University Press, 1995 22 Chen Jianding, Zheng Anxi, Wu Xuqin. In-situ compounding of thermoplastics and liquid crystal copolyesters.

Journal of Functional Polymers, 1995 23 Zhang Hongfang, Zhang Jingping, Yu Wen, et al. The structure and properties of thermotropic liquid crystal 1701 blends. Journal of Functional Polymers, 1995, 83乜320 24 Metres, Liu Xiaobo, Cai Xingxian. Liquid Crystalline Polyesterimide Bismaleimide Molecular Composites 27 Xie Ping, Li Cheng Zhang Weiben. Functional ladder-shaped polysiloxanes with phase characteristics of liquid crystals.

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