阅读说明：本技术 一种点击修饰的聚硅氧烷侧链液晶高分子的制备方法 (Preparation method of click-modified polysiloxane side chain liquid crystal polymer ) 是由 洪希杭 王冬 王慧东 于 2020-06-28 设计创作，主要内容包括：本发明专利公开一种点击修饰的聚硅氧烷侧链液晶高分子的制备方法,首先采用微波辐照制备对烯氧基苯甲酸,紫外和激光照射联合技术制备出4-烯丙氧基苯甲酰氯及液晶性单体,然后利用回流反应制备对碘烯丙氧基和对-(二丁基氨基)苯基乙炔,上述物质在紫外、激光及微波联合作用下依据硅氢加成反应原理合成出聚硅氧烷侧链液晶高分子白色固体,再经三键修饰、点击化学修饰制备出点击修饰的聚硅氧烷侧链液晶高分子。该技术充分利用微波、紫外及激光的化学能量对材料进行合成和精确点位的化学修饰,能够克服产物纯度不足、催化剂不易移除等缺陷,并获得性能优异的液晶高分子材料,该技术也为材料的快速控制合成和工业化生产提供了一条可行的技术路线。(The invention discloses a preparation method of a click-modified polysiloxane side chain liquid crystal polymer, which comprises the steps of firstly preparing p-alkenyloxybenzoic acid by adopting microwave irradiation, preparing 4-allyloxybenzoyl chloride and a liquid crystal monomer by adopting an ultraviolet and laser irradiation combined technology, then preparing p-iodoallyloxy and p- (dibutylamino) phenylacetylene by utilizing a reflux reaction, synthesizing a polysiloxane side chain liquid crystal polymer white solid by the substances under the combined action of ultraviolet, laser and microwave according to a hydrosilylation reaction principle, and then preparing the click-modified polysiloxane side chain liquid crystal polymer by carrying out triple bond modification and click chemical modification. The technology makes full use of the chemical energy of microwave, ultraviolet and laser to synthesize the material and chemically modify the precise point position, can overcome the defects of insufficient product purity, difficult removal of the catalyst and the like, obtains the liquid crystal polymer material with excellent performance, and provides a feasible technical route for the rapid control synthesis and the industrial production of the material.)

1. The invention provides a preparation method of a click-modified polysiloxane side chain liquid crystal polymer, which has the following structural general formula:

wherein: m, p and q are integers more than or equal to 3, and n is an integer between 0 and 16;

r is selected fromIn the above-mentioned manner, the first and second substrates are,

one of the used liquid crystal monomers is cholesteryl p-alkenyloxybenzoate, and the structural formula is as follows:

the other liquid crystal monomer is p-alkenyloxy benzoic acid alcohol ester, and the structural formula is as follows:

wherein R isOne of (1);

the click modification moiety used has the general structural formula:

the invention provides a preparation method of a click-modified polysiloxane side chain liquid crystal polymer, which is implemented by carrying out hydrosilylation on polymethyl hydrogen-containing silicone oil, p-alkenyloxy benzoic acid cholesterol ester and/or p-alkenyloxy benzoic acid alcohol ester and p-iodoallyloxy benzene, then reacting the hydrosilylation with p- (dibutylamino) phenyl acetylene, and finally carrying out click reaction with 7,7,8, 8-tetracyano-p-benzoquinone dimethane, tetracyano-ethylene, 2,3,5, 6-tetrafluoro-7, 7',8,8' -tetracyano-dimethane to obtain polysiloxane side chain liquid crystal polymers with different properties, and specifically adopting the following technical scheme:

step one, preparation of p-alkenyloxy benzoic acid

Putting a mixture of 0.001-0.100 mol of ethyl p-hydroxybenzoate, 0.001-0.100 mol of alkene bromide, 0.001-0.100 mol of solid potassium carbonate and 100-500 mL of acetone into a 100-1000 mL flask, then moving the flask into a normal-pressure reflux microwave reactor with ultraviolet and Nd, YAG solid pulse laser, and only starting microwave energy, wherein the microwave power is 500-1000W, the frequency is 2450MHz, the heating temperature is 25-200 ℃, the heating time is 1-36 h, reflux condensation is carried out during microwave heating, when the temperature in the microwave reactor exceeds a preset temperature, the microwave generator is closed to reduce the temperature, when the temperature is lower than the preset temperature, the microwave generator is opened to increase the temperature, and a reflux condensing device is started in the reaction process; after the microwave is finished, filtering the obtained product, carrying out rotary evaporation at the speed of 80-100 r/min at the temperature of 30 ℃ until acetone is removed, adding 100-300 mL of diethyl ether into the product, adding 100mL of distilled water, stirring for 5-10 min, standing for layering, separating an ether layer from a distilled water layer, extracting the ether layer twice by using 50-200 mL of 5-30% NaOH aqueous solution, evaporating the diethyl ether at the temperature of 35-40 ℃, adding the obtained residue into 300mL of ethanol containing 30g of KOH according to the mass ratio of 1:2, boiling until the residue is dissolved, cooling the solution to room temperature, stirring the solution at the speed of 100-2000 r/min, simultaneously adding 6mol/L of hydrochloric acid solution, adjusting the pH value to be 1-2, filtering the obtained product to obtain a crude product, stirring and washing the filtered solid phase substance by using 300mL of distilled water for 30min, adding the washed product into ethanol which is heated and stirred under reflux at the temperature of 80 ℃, until the product is not dissolved any more, quickly cooling the product in a refrigerator at 5 ℃ for 10-30 min, filtering the mixture to obtain white needle crystals, and drying the crystal product at 30-60 ℃ for 12-72 h in vacuum to obtain p-alkenyloxy benzoic acid;

step two, preparation of 4-allyloxybenzoyl chloride

Adding the white needle crystal obtained in the step one and 5-30 mL of thionyl chloride into a 20-100 mL flask with a hydrogen chloride absorption instrument, and transferring the flask into a normal-pressure reflux microwave reactor with ultraviolet and Nd-YAG solid pulse laserIn the method, the flask is opened to be irradiated by ultraviolet light and laser, wherein the ultraviolet wavelength is 190-400 nm, and the power is 5mW/cm²～15W/cm²The Nd is YAG solid pulse laser wavelength 1.06 mu m, pulse width 1.2ms, spot diameter 0.2-6 mm, repetition frequency 2-40 Hz, power density 1.0 × 10⁶W/cm²The light spot of the laser focus is 1-3 mm below the liquid level, the irradiation time is 0.1-20 h, the irradiation temperature is 20-200 ℃, the mixture is stirred at the speed of 200-2000 r/min in the irradiation process, reflux condensation is carried out during heating, then the solution is taken out, and the excessive thionyl chloride is removed by reduced pressure distillation for 10min under the conditions of-0.09 MPa and 40 ℃, so as to obtain 4-allyloxybenzoyl chloride;

step three, preparation of liquid crystal monomer p-alkenyloxy benzoic acid cholesterol ester

Dissolving the obtained 4-allyloxybenzoyl chloride in 1-50 mL of dry dichloromethane, adding 0.01-1.00 mmol of cholesterol and 1-20 mL of pyridine into 50-200 mL of dry dichloromethane, dropwise adding the 4-allyloxybenzoyl chloride solution into a dichloromethane cold liquid containing cholesterol and pyridine, transferring the mixed liquid into a normal-pressure microwave reactor with reflux of ultraviolet and Nd: YAG solid pulse laser, and only starting ultraviolet light and laser to irradiate the flask, wherein the ultraviolet wavelength is 190-400 nm, and the power is 5mW/cm²～15W/cm²The Nd is YAG solid pulse laser wavelength 1.06 mu m, pulse width 1.2ms, spot diameter 0.2-6 mm, repetition frequency 2-40 Hz, power density 1.0 × 10⁶W/cm²A light spot of a laser focus is 1-3 mm below a liquid level, the irradiation time is 0.1-10 h, the irradiation temperature is 20-200 ℃, the mixture is stirred at the speed of 200-2000 r/min and is subjected to reflux condensation simultaneously in the irradiation process, then the solution is taken out, 100-500 mL of ethanol is added into the filtrate to precipitate a crude product, the crude product is recrystallized from the ethanol, and the obtained white powder product is dried in a vacuum drying oven at the temperature of 50-80 ℃ for 6-72 h to obtain the p-alkenyloxy benzoic acid cholesterol ester;

step four, preparation of liquid crystal monomer p-alkenyloxy benzoic alcohol ester

Dissolving the 4-allyloxybenzoyl chloride obtained in the second step in 5-20 mL of dry dichloromethane, and dripping into a solution containing 0.01-0.20 mol of R-OH and 3-20 mL of pyridineTransferring the mixture into a flask in a cold solution of pyridine in 100mL of dichloromethane, transferring the mixture into a normal-pressure microwave reactor with reflux of ultraviolet and Nd-YAG solid pulse laser, and only starting the ultraviolet light and the laser to irradiate the flask, wherein the ultraviolet wavelength is 190-400 nm, and the power is 5mW/cm²～15W/cm²YAG solid pulse laser wavelength 1.06 μm, pulse width 1.2ms, spot diameter 0.2mm, repetition frequency 20Hz, power density 1.0 × 10⁶W/cm²The method comprises the following steps of (1) enabling a light spot of a laser focus to be 2mm below a liquid level, enabling the irradiation time to be 4-10 hours, enabling the irradiation temperature to be 20-50 ℃, stirring a mixture at a speed of 200-2000 r/min in the irradiation process, simultaneously carrying out reflux condensation, then taking out a solution, adding 300mL of ethanol into a filtrate to precipitate a crude product, recrystallizing the crude product from the ethanol, and drying an obtained white powder product in a vacuum drying oven at the temperature of 50-80 ℃ for 12-48 hours to obtain p-alkenyloxy benzoic acid alcohol ester;

step five, preparation of p-iodoallyloxy

Dissolving 0.01-0.10 mol of p-iodophenol in 10-100 mL of acetonitrile, stirring for 5-10 min, then placing in a 30-300 mL flask, adding 0.01-0.10 mol of 3-bromopropylene and 0.01-0.10 mol of potassium carbonate, heating to 85 ℃, stirring at 100-2000 r/min, carrying out water bath heat preservation reflux reaction for 1-5 h, carrying out centrifugal separation after reaction to remove solids, carrying out rotary evaporation for 10-300 min at the speed of-0.09 MPa, the temperature of 40-80 ℃ and the speed of 80-100 r/min to remove excess solvent, and then carrying out silica gel column chromatography purification by taking a mixture of dichloromethane and petroleum ether with the volume ratio of 1:2 as an eluent to obtain p-iodoallyloxy;

step six, preparation of p- (dibutylamino) phenylacetylene

Dissolving 5-100 mmol of para-iodoaniline and 5-100 mmol of bromobutane or iodomethane in 10-200 mL of N, N-dimethylformamide, adding 5-100 mmol of potassium carbonate and 5-100 mmol of potassium iodide, placing the mixture in a 40KHz ultrasonic cleaning instrument for ultrasonic oscillation for 20-40 min, introducing argon gas for removing oxygen at 0.1-2L/min, carrying out water bath reflux reaction on a 20-500 mL flask containing the mixture at 80-150 ℃ for 15-24 h, plugging a reflux condenser tube opening with a rubber plug, carrying out suction filtration after the reaction to remove solids, extracting with 30-300 mL of water and 30-300 mL of dichloromethane to remove N, N-dimethylformamide, rotary evaporating at-0.09 MPa, 25-50 deg.C and 90r/min for 10-200 min to remove excessive solvent, then, using a mixture of dichloromethane and petroleum ether with a volume ratio of 1:6 as eluent to carry out silica gel column chromatography purification, thus obtaining a p- (dibutylamino) phenylacetylene product; dissolving 0.001-0.100 mol of product in 50-100 mL of mixed solution of triethylamine and tetrahydrofuran in a volume ratio of 1:1, introducing argon gas at 0.1-2L/min, ultrasonically deoxidizing at 40KHz for 30min, then adding 0.001-0.100 mol of trimethylsilyl acetylene TMSA, 0.1-1.0 mmol of bis (triphenylphosphine) palladium dichloride and 0.1-1.0 mmol of cuprous iodide, stirring in a 100-300 mL flask containing the mixture at a speed of 100-2000 r/min, carrying out a water bath reflux reaction at 25-60 ℃ for 8-12 h, plugging a reflux condenser pipe orifice with a rubber plug, carrying out suction filtration after the reaction to remove solids, carrying out vacuum evaporation at a speed of-0.09 MPa, 40-80 ℃ and 80-100 r/min for 30min to remove more solvent, and then carrying out silica gel column chromatography purification by taking a mixture of dichloromethane and petroleum ether in a volume ratio of 1:6 as eluent to obtain yellow liquid; dissolving 0.001-0.100 mol of the product and 0.001-0.100 mol of potassium carbonate in 30-100 mL of a mixed solution of tetrahydrofuran and absolute ethyl alcohol with a volume ratio of 7:3, transferring the mixed solution into a 50-300 mL flask, stirring the mixture in the flask at 100-2000 r/min, carrying out reflux reaction at room temperature for 2-10 h, stopping the reaction, carrying out suction filtration to remove solids, carrying out rotary evaporation at a vacuum degree of-0.09 MPa, a temperature of 40-80 ℃ and a rotating speed of 80-100 r/min for 20-60 min to remove the solvent, and carrying out dichloromethane column chromatography purification to obtain a yellow oily liquid;

step seven, 4-ethynyl-N, N-hexacosanylaniline preparation

Dissolving 5-100 mmol of p-iodoaniline and 5-100 mmol of 1-bromohexadecane in 10-200 mLN, N-dimethylformamide, then adding 5-100 mmol of potassium carbonate and 5-100 mmol of potassium iodide, placing the mixture in a 40KHz ultrasonic cleaning instrument for ultrasonic oscillation for 20-40 min, introducing argon gas for removing oxygen at 0.1-2L/min, carrying out water bath reflux reaction on a 20-500 mL flask containing the mixture at 80-150 ℃ for 15-24 h, plugging a reflux condenser tube opening with a rubber plug, carrying out suction filtration after the reaction to remove solids, extracting with 30-300 mL of water and 30-300 mL of dichloromethane to remove N, N-dimethylformamide, rotary evaporating at-0.09 MPa, 25-50 deg.C and 90r/min for 10-200 min to remove excessive solvent, then, using a mixture of dichloromethane and petroleum ether with a volume ratio of 1:6 as an eluent to carry out silica gel column chromatography purification, thus obtaining a product; dissolving 0.001-0.100 mol of the product in 50-100 mL of mixed solution of triethylamine and tetrahydrofuran in a volume ratio of 1:1, introducing argon gas at 0.1-2L/min, ultrasonically deoxidizing at 40KHz for 30min, then adding 0.001-0.100 mol of trimethylsilyl acetylene TMSA, 0.1-1.0 mmol of bis (triphenylphosphine) palladium dichloride and 0.2mmol of cuprous iodide, stirring in a 100-300 mL flask containing the mixture at a speed of 100-2000 r/min, carrying out reflux reaction in a water bath at 25-60 ℃ for 8-12 h, plugging a reflux condenser pipe orifice with a rubber plug, carrying out suction filtration after the reaction to remove solids, carrying out vacuum evaporation for 30min at a speed of-0.09 MPa, 40-80 ℃ and 80-100 r/min to remove more solvent, and then carrying out silica gel column chromatography purification by taking a mixture of dichloromethane and petroleum ether in a volume ratio of 1:6 as an eluent to obtain yellow liquid; dissolving 0.001-0.100 mol of product and 0.001-0.100 mol of potassium carbonate in 30-100 mL of a mixture of tetrahydrofuran and absolute ethyl alcohol with a volume ratio of 7:3, transferring the mixture into a 50-300 mL flask, stirring the mixture in the flask at 100-2000 r/min, carrying out reflux reaction at room temperature for 2-10 h, stopping the reaction, carrying out suction filtration to remove solids, carrying out rotary evaporation at a vacuum degree of-0.09 MPa, a temperature of 40-80 ℃ and a rotating speed of 80-100 r/min for 20-60 min to remove the solvent, and carrying out dichloromethane column chromatography purification to obtain a yellow oily liquid;

step eight, preparing white solid of polysiloxane side chain liquid crystal polymer by hydrosilylation reaction

Adding 0.10-5.00 mmol of liquid crystal monomer cholesterol p-alkenyloxybenzoate, 0.10-5.00 mmol of p-iodoallyloxy and 10-10 ppm of platinum catalyst into a flask for reaction, adding the mixture into 10-50 mL of toluene, evacuating the flask through a double-row pipe and filling nitrogen to remove oxygen in the flask, transferring the flask into an atmospheric pressure belt reflux microwave reactor with ultraviolet and Nd: YAG solid pulse laser, and irradiating the solution with Nd: YAG solid pulse laser, wherein the laser parameters are 1.06 mu m in wavelength, 1.2ms in pulse width, 0.2-6 mm in spot diameter, 2-40 Hz in repetition frequency and 1.0 × 10 in power density⁶W/cm²The light spot of the laser focus is 1-3 mm below the liquid level, and the irradiation time is 0.1-24 h; laser irradiationIn the process, simultaneously starting an ultraviolet lamp for irradiation, wherein the wavelength of the ultraviolet light is 190-400 nm, and the intensity is 5mW/cm²～15W/cm²The irradiation time is 0.1-24 h, the microwave heating is synchronously started while the laser and the ultraviolet irradiation are carried out, the microwave frequency is 2450MHz, the microwave power is 300-1000W, the microwave time is 0.1-24 h, the heating temperature is 25-100 ℃, the microwave generator is closed to reduce the temperature when the temperature in the microwave reactor exceeds the set temperature, the microwave generator is opened to increase the temperature when the temperature is lower than the set temperature, the reflux condensation is started, the opening of a reflux condensation pipe is blocked by a rubber plug to prevent air from entering, 200-500 mg of polymethyl hydrogen silicone oil PMHS is added under the condition of keeping vacuum after the reaction is finished, and then Nd: YAG solid pulse laser is used for irradiating the solution, wherein the laser parameters are 1.06 mu m in wavelength, 1.2ms in pulse width, 0.2-6 mm in spot diameter, 2-40 Hz in repetition frequency and 1.0 × 10⁶W/cm²The light spot of the laser focus is 1-3 mm below the liquid level, and the irradiation time is 0.1-24 h; in the laser irradiation process, simultaneously starting an ultraviolet lamp for irradiation, wherein the wavelength of ultraviolet light is 190-400 nm, and the power is 5mW/cm²～15W/cm²The irradiation time is 0.1-24 h; simultaneously carrying out laser and ultraviolet irradiation, synchronously starting microwave heating, wherein the microwave frequency is 2450MHz, the microwave power is 300-1000W, the microwave time is 0.1-24 h, the heating temperature is 60-100 ℃, when the temperature in the microwave reactor exceeds a set temperature, a microwave generator is closed to reduce the temperature, and when the temperature in the microwave reactor is lower than the set temperature, the microwave generator is opened to increase the temperature; after the reaction is finished, taking out the reaction liquid, cooling the reaction liquid to room temperature, dropwise adding the reaction liquid into 20-500 mL of methanol under the condition of mechanical stirring at 100-1000 r/min, centrifugally separating at 7000r/min, re-dissolving the solid phase substance into 20-500 mL of chloroform, precipitating with 20-500 mL of methanol to remove unreacted raw materials, and drying at 70-80 ℃ for 6-72 hours to obtain white solid of the polysiloxane side chain liquid crystal polymer;

step nine, preparation of polysiloxane side chain liquid crystal polymer modified by triple bond

Dissolving 50-150 mg of liquid crystal polymer prepared by hydrosilylation reaction and 0.10-1.00 mmol of p- (dibutylamino) phenylacetylene or 4-ethynyl-N, N-hexacosanylaniline in 5-30 mL of triethylamine and tetrahydrofuran solution with a volume ratio of 1:1, introducing 0.1-2L/min of argon, ultrasonically deoxidizing for 30min under the condition of 40KHz, adding 0.1-1.0 mmol of bis (triphenylphosphine) palladium dichloride and 0.1-1.0 mmol of cuprous iodide, stirring at 100-2000 r/min, refluxing and reacting in water bath at 40 ℃ for 5-20 h, centrifugally separating at 7000r/min to remove solids, dropwise adding the liquid product into 100-500 mL of methanol solution under stirring at a rotating speed of 100-2000 r/min, centrifugally separating at 7000r/min, redissolving the precipitate in 100-500 mL of trichloromethane, precipitating with 20-500 mL of methanol to remove unreacted raw materials, obtaining polysiloxane side chain liquid crystal polymer modified by triple bonds;

step ten, click reaction preparation of click-modified polysiloxane side chain liquid crystal polymer

And (4) adding the polysiloxane side chain liquid crystal polymer obtained in the step nine into 5-50 mL of methanol, adding a click chemistry modified micromolecule monomer into the other 5-50 mL of methanol, and mixing the two solutions to prepare the click modified polysiloxane side chain liquid crystal polymer through click reaction.

2. The method for preparing a click-modified polysiloxane side chain liquid crystal polymer according to claim 1, wherein: in the preparation of the p-alkenyloxybenzoic acid, the p-alkenyloxybenzoic acid is obtained by reacting ethyl p-hydroxybenzoate with allyl bromide.

3. The method for preparing a click-modified polysiloxane side chain liquid crystal polymer according to claim 1, wherein: in the preparation of the p-alkenyloxybenzoic acid, the alkene bromine is one or any combination of two or more than two of 3-bromine-1-propylene, 5-bromine-1-pentene and 13-bromine-1-tridecene.

4. The method for preparing a click-modified polysiloxane side chain liquid crystal polymer according to claim 1, wherein: in the preparation of the liquid crystal polymer by the hydrosilylation reaction, when the polymethyl hydrogen-containing silicone oil reacts with two liquid crystal monomers, one of the two liquid crystal monomers is 0, but not both of the two liquid crystal monomers are 0.

5. The method for preparing a click-modified polysiloxane side chain liquid crystal polymer according to claim 1, wherein: in the preparation of the liquid crystal monomer-p-alkenyloxy benzoic acid cholesterol ester, the p-alkenyloxy benzoic acid cholesterol ester is obtained by esterifying p-alkenyloxy benzoic acid and cholesterol.

6. The method for preparing a click-modified polysiloxane side chain liquid crystal polymer according to claim 1, wherein: in the preparation of the liquid crystalline monomer p-alkenyloxy benzoic alcohol ester, the p-alkenyloxy benzoic alcohol ester is obtained by esterifying p-alkenyloxy benzoic acid and R-OH, wherein R is selected from

7. The method for preparing a click-modified polysiloxane side chain liquid crystal polymer according to claim 1, wherein: the solvent used in the polysiloxane side chain liquid crystal polymer prepared by click modification is dichloromethane, and the small molecular monomer is one, two or more of 7,7,8, 8-tetracyanoquinodimethane, tetracyanoethylene, 2,3,5, 6-tetrafluoro-7, 7',8,8' -tetracyanoquinodimethane, wherein the dichloromethane is 5-30 mL, the 7,7,8, 8-tetracyanoterephthalquinodimethane is 10-100 mg, the 2,3,5, 6-tetrafluoro-7, 7',8,8' -tetracyanoquinodimethane is 10-100 mg, and the tetracyanoethylene is 1-50 mg.

8. The method for preparing a click-modified polysiloxane side chain liquid crystal polymer according to claim 1, wherein: the polysiloxane side chain liquid crystal polymer prepared by click modification has a polysiloxane main chain, has good surface energy, mechanical and thermal stability, and can graft side chains with different properties through hydrosilylation reaction, so that the polysiloxane side chain liquid crystal polymer shows liquid crystallinity and nonlinear optical effect.

9. The method for preparing a click-modified polysiloxane side chain liquid crystal polymer according to claim 1, wherein: according to the polysiloxane side chain liquid crystal polymer prepared by click modification, the grafted side chain is a chiral compound named as p-alkenyloxy benzoic acid cholesterol ester, wherein m is an integer larger than 3, so that linear polysiloxane can show liquid crystallinity.

10. The method for preparing a click-modified polysiloxane side chain liquid crystal polymer according to claim 1, wherein: according to the linear polysiloxane displaying liquid crystallinity, the grafted side chain is a compound of substitution termination of achiral different polar groups, and the introduction of the side chain can achieve that the polysiloxane side chain liquid crystal polymer has different phase structures, wherein p is an integer larger than or equal to 3, and different polar groups are cyano-group, methoxy-group and phenyl-group structures.

11. The method for preparing a click-modified polysiloxane side chain liquid crystal polymer according to claim 1, wherein: according to the linear polysiloxane for displaying the nonlinear optical effect, the grafted side chain of the linear polysiloxane is an organic conjugated group modified by click chemistry, and the linear polysiloxane has a good chromophore structure for an acceptor after click modification, so that the linear polysiloxane displays good third-order nonlinear optical effect, wherein q is an integer larger than or equal to 3, and n is an integer from 0 to 16.

[ technical field ]: the invention belongs to the field of organic material synthesis, and particularly relates to a preparation method of a click-modified polysiloxane side chain liquid crystal polymer.

[ technical background ]: a liquid crystal high-molecular polymer integrates the anisotropy of liquid crystal and the mechanical property of polymer, has the characteristics of good processability, optical anisotropy, dielectric anisotropy and the like, and is widely applied to the fields of photoelectricity, biology, high-strength and high-modulus fibers, plastic engineering and the like (Yao W, Gao Y, Yuan X, et al, Synthesis and self-assembly fibers based on the polysiloxane back bone [ J ] J.Mater.chem.C,2016,4(7):1425 and 1440.).

The polysiloxane side chain liquid crystal polymer is a liquid crystal polymer material formed by taking polysiloxane oligomers or Polymers as a main chain and suspending liquid crystal micromolecule units on side chains, and a large number of theoretical and experimental results show that the small-molecule liquid crystal units have great freedom to obtain the optimal arrangement with the lowest energy in the process of synthesizing the polysiloxane side chain liquid crystal polymer because the bond energy of Si-O bonds is lower than that of C-C bonds, so that the obtained polymer has lower glass transition temperature and wider liquid crystal phase temperature range (Zhang L Y, Yao W H, Gao Y Z, et al.

At present, polysiloxane side chain liquid crystal polymers are generally obtained by grafting alkenyl liquid crystalline monomers onto hydrogen-containing silicone oil through a traditional hydrosilylation reaction, and the method has two technical difficulties to be overcome: firstly, how to completely remove noble metal platinum used in the synthesis process in subsequent purification; secondly, the target product is actually a mixture of the Ma addition product and the anti-Ma addition product, and the structure and performance characterization of a single product (rebuke drijin, Chen satellite, Zhu Sheng Bo, etc.. the synthesis and performance research of polysiloxane side chain cholesterol ester liquid crystal polymer [ J]Application chemical, 2019,048(003): 517-520). In order to solve the problem, the invention provides a preparation method of a click-modified polysiloxane side chain liquid crystal polymer, which utilizes microwave irradiation, ultraviolet and Nd: YAG (Neodymium-doped yttrium aluminum garnet, Nd: Y)₃Al₅O₁₂) The synthesis technology utilizes the chemical energy of microwave, ultraviolet and laser to synthesize materials and chemically modify precise point positions, thereby overcoming the defects of insufficient product purity and the like and obtaining the liquid crystal polymer material with excellent performance; meanwhile, the technical route has the advantages of simple operation, concentrated reaction energy, easy industrialization of operation and the like, has bright application prospect, and provides a new idea for rapid synthesis and product purification of materials of the same type.

[ summary of the invention ]: the invention aims to provide a preparation method of a click-modified polysiloxane side chain liquid crystal polymer, which comprises the steps of firstly preparing p-alkenyloxybenzoic acid by adopting a microwave irradiation method, then respectively preparing 4-allyloxybenzoyl chloride and a liquid crystal monomer by utilizing ultraviolet and Nd-YAG solid pulse laser combined technology, then preparing p-iodoallyloxy and p- (dibutylamino) phenylacetylene by utilizing a reflux reaction, further synthesizing white polysiloxane side chain liquid crystal polymer solid by utilizing the substances under the combination of laser, ultraviolet and microwave according to a hydrosilylation reaction principle, then carrying out triple bond modification and click chemical modification to prepare the click-modified polysiloxane side chain liquid crystal polymer, wherein the performances of the polysiloxane side chain liquid crystal polymer can be adjusted by adjusting the length of a carbon chain in a spacer, the structure of the side chain liquid crystal monomer and the grafting molar ratio of a click modification part, the obtained substance can be used in the fields of photoelectricity, biology, plastic engineering and the like, and the synthetic method also provides a feasible technical route for the rapid control synthesis and the industrial production of the polysiloxane side chain liquid crystal polymer.

[ technical solution of the present invention ]:

the invention provides a preparation method of a click-modified polysiloxane side chain liquid crystal polymer, which has the following structural general formula:

wherein: m, p and q are integers more than or equal to 3, and n is an integer between 0 and 16;

r is selected from

In the above-mentioned manner, the first and second substrates are,

one of the used liquid crystal monomers is cholesteryl p-alkenyloxybenzoate, and the structural formula is as follows:

the other liquid crystal monomer is p-alkenyloxy benzoic acid alcohol ester, and the structural formula is as follows:

wherein R isOne of (1);

the click modification moiety used has the general structural formula:

the invention provides a preparation method of a click-modified polysiloxane side chain liquid crystal polymer, which is implemented by carrying out hydrosilylation on polymethyl hydrogen-containing silicone oil, p-alkenyloxy benzoic acid cholesterol ester and/or p-alkenyloxy benzoic acid alcohol ester and p-iodoallyloxy benzene, then reacting the hydrosilylation with p- (dibutylamino) phenyl acetylene, and finally carrying out click reaction with 7,7,8, 8-tetracyano-p-benzoquinone dimethane, tetracyano-ethylene, 2,3,5, 6-tetrafluoro-7, 7',8,8' -tetracyano-dimethane to obtain polysiloxane side chain liquid crystal polymers with different properties, and specifically adopting the following technical scheme:

step one, preparation of p-alkenyloxy benzoic acid

Putting a mixture of 0.001-0.100 mol of ethyl p-hydroxybenzoate, 0.001-0.100 mol of alkene bromide, 0.001-0.100 mol of solid potassium carbonate and 100-500 mL of acetone into a 100-1000 mL flask, then moving the flask into a normal-pressure reflux microwave reactor with ultraviolet and Nd, YAG solid pulse laser, and only starting microwave energy, wherein the microwave power is 500-1000W, the frequency is 2450MHz, the heating temperature is 25-200 ℃, the heating time is 1-36 h, reflux condensation is carried out during microwave heating, when the temperature in the microwave reactor exceeds a preset temperature, the microwave generator is closed to reduce the temperature, when the temperature is lower than the preset temperature, the microwave generator is opened to increase the temperature, and a reflux condensing device is started in the reaction process; after the microwave is finished, filtering the obtained product, carrying out rotary evaporation at the speed of 80-100 r/min at the temperature of 30 ℃ until acetone is removed, adding 100-300 mL of diethyl ether into the product, adding 100mL of distilled water, stirring for 5-10 min, standing for layering, separating an ether layer from a distilled water layer, extracting the ether layer twice by using 50-200 mL of 5-30% NaOH aqueous solution, evaporating the diethyl ether at the temperature of 35-40 ℃, adding the obtained residue into 300mL of ethanol containing 30g of KOH according to the mass ratio of 1:2, boiling until the residue is dissolved, cooling the solution to room temperature, stirring the solution at the speed of 100-2000 r/min, simultaneously adding 6mol/L of hydrochloric acid solution, adjusting the pH value to be 1-2, filtering the obtained product to obtain a crude product, stirring and washing the filtered solid phase substance by using 300mL of distilled water for 30min, adding the washed product into ethanol which is heated and stirred under reflux at the temperature of 80 ℃, until the product is not dissolved any more, quickly cooling the product in a refrigerator at 5 ℃ for 10-30 min, filtering the mixture to obtain white needle crystals, and drying the crystal product at 30-60 ℃ for 12-72 h in vacuum to obtain p-alkenyloxy benzoic acid;

step two, preparation of 4-allyloxybenzoyl chloride

Adding the white needle-shaped crystal obtained in the step one and 5-30 mL of thionyl chloride into a 20-100 mL flask with a hydrogen chloride absorber, transferring the flask into a normal-pressure reflux microwave reactor with ultraviolet and Nd-YAG solid pulse laser, starting ultraviolet light and laser irradiation on the flask, wherein the ultraviolet wavelength is 190-400 nm, and the power is 5mW/cm²～15W/cm²The Nd is YAG solid pulse laser wavelength 1.06 mu m, pulse width 1.2ms, spot diameter 0.2-6 mm, repetition frequency 2-40 Hz, power density 1.0 × 10⁶W/cm²The light spot of the laser focus is 1-3 mm below the liquid level, the irradiation time is 0.1-20 h, the irradiation temperature is 20-200 ℃, the mixture is stirred at the speed of 200-2000 r/min in the irradiation process, reflux condensation is carried out during heating, then the solution is taken out, and the excessive thionyl chloride is removed by reduced pressure distillation for 10min under the conditions of-0.09 MPa and 40 ℃, so as to obtain 4-allyloxybenzoyl chloride;

step three, preparation of liquid crystal monomer p-alkenyloxy benzoic acid cholesterol ester

Dissolving the obtained 4-allyloxybenzoyl chloride in 1-50 mL of dry dichloromethane, adding 0.01-1.00 mmol of cholesterol and 1-20 mL of pyridine into 50-200 mL of dry dichloromethane, dropwise adding the 4-allyloxybenzoyl chloride solution into a dichloromethane cold liquid containing cholesterol and pyridine, transferring the mixed liquid into a normal-pressure microwave reactor with reflux of ultraviolet and Nd: YAG solid pulse laser, and only starting ultraviolet light and laser to irradiate the flask, wherein the ultraviolet wavelength is 190-400 nm, and the power is 5mW/cm²～15W/cm²The Nd is YAG solid pulse laser wavelength 1.06 mu m, pulse width 1.2ms, spot diameter 0.2-6 mm, repetition frequency 2-40 Hz, power density 1.0 × 10⁶W/cm²A light spot of a laser focus is 1-3 mm below a liquid level, the irradiation time is 0.1-10 h, the irradiation temperature is 20-200 ℃, the mixture is stirred at the speed of 200-2000 r/min and is subjected to reflux condensation simultaneously in the irradiation process, then the solution is taken out, 100-500 mL of ethanol is added into the filtrate to precipitate a crude product, the crude product is recrystallized from the ethanol, and the obtained white powder product is dried in a vacuum drying oven at the temperature of 50-80 ℃ for 6-72 h to obtain the p-alkenyloxy benzoic acid cholesterol ester;

step four, preparation of liquid crystal monomer p-alkenyloxy benzoic alcohol ester

Dissolving the 4-allyloxybenzoyl chloride obtained in the second step in 5-20 mL of dry dichloromethane, dripping the solution into a cold solution containing 0.01-0.20 mol of R-OH and 3-20 mL of pyridine in 100mL of dichloromethane, transferring the mixture into a flask, transferring the flask into a microwave reactor with ultraviolet, Nd and YAG solid pulse laser and normal pressure backflow, and only starting ultraviolet light and laser to irradiate the flask, wherein the ultraviolet wavelength is 190-400 nm, and the power is 5mW/cm²～15W/cm²YAG solid pulse laser wavelength 1.06 μm, pulse width 1.2ms, spot diameter 0.2mm, repetition frequency 20Hz, power density 1.0 × 10⁶W/cm²The method comprises the following steps of (1) enabling a light spot of a laser focus to be 2mm below a liquid level, enabling the irradiation time to be 4-10 hours, enabling the irradiation temperature to be 20-50 ℃, stirring a mixture at a speed of 200-2000 r/min in the irradiation process, simultaneously carrying out reflux condensation, then taking out a solution, adding 300mL of ethanol into a filtrate to precipitate a crude product, recrystallizing the crude product from the ethanol, and drying an obtained white powder product in a vacuum drying oven at the temperature of 50-80 ℃ for 12-48 hours to obtain p-alkenyloxy benzoic acid alcohol ester;

step five, preparation of p-iodoallyloxy

Dissolving 0.01-0.10 mol of p-iodophenol in 10-100 mL of acetonitrile, stirring for 5-10 min, then placing in a 30-300 mL flask, adding 0.01-0.10 mol of 3-bromopropylene and 0.01-0.10 mol of potassium carbonate, heating to 85 ℃, stirring at 100-2000 r/min, carrying out water bath heat preservation reflux reaction for 1-5 h, carrying out centrifugal separation after reaction to remove solids, carrying out rotary evaporation for 10-300 min at the speed of-0.09 MPa, the temperature of 40-80 ℃ and the speed of 80-100 r/min to remove excess solvent, and then carrying out silica gel column chromatography purification by taking a mixture of dichloromethane and petroleum ether with the volume ratio of 1:2 as an eluent to obtain p-iodoallyloxy;

step six, preparation of p- (dibutylamino) phenylacetylene

Dissolving 5-100 mmol of para-iodoaniline and 5-100 mmol of bromobutane or iodomethane in 10-200 mL of N, N-dimethylformamide, adding 5-100 mmol of potassium carbonate and 5-100 mmol of potassium iodide, placing the mixture in a 40KHz ultrasonic cleaning instrument for ultrasonic oscillation for 20-40 min, introducing argon gas for removing oxygen at 0.1-2L/min, carrying out water bath reflux reaction on a 20-500 mL flask containing the mixture at 80-150 ℃ for 15-24 h, plugging a reflux condenser tube opening with a rubber plug, carrying out suction filtration after the reaction to remove solids, extracting with 30-300 mL of water and 30-300 mL of dichloromethane to remove N, N-dimethylformamide, rotary evaporating at-0.09 MPa, 25-50 deg.C and 90r/min for 10-200 min to remove excessive solvent, then, using a mixture of dichloromethane and petroleum ether with a volume ratio of 1:6 as eluent to carry out silica gel column chromatography purification, thus obtaining a p- (dibutylamino) phenylacetylene product; dissolving 0.001-0.100 mol of product in 50-100 mL of mixed solution of triethylamine and tetrahydrofuran in a volume ratio of 1:1, introducing argon gas at 0.1-2L/min, ultrasonically deoxidizing at 40KHz for 30min, then adding 0.001-0.100 mol of trimethylsilyl acetylene TMSA, 0.1-1.0 mmol of bis (triphenylphosphine) palladium dichloride and 0.1-1.0 mmol of cuprous iodide, stirring in a 100-300 mL flask containing the mixture at a speed of 100-2000 r/min, carrying out a water bath reflux reaction at 25-60 ℃ for 8-12 h, plugging a reflux condenser pipe orifice with a rubber plug, carrying out suction filtration after the reaction to remove solids, carrying out vacuum evaporation at a speed of-0.09 MPa, 40-80 ℃ and 80-100 r/min for 30min to remove more solvent, and then carrying out silica gel column chromatography purification by taking a mixture of dichloromethane and petroleum ether in a volume ratio of 1:6 as eluent to obtain yellow liquid; dissolving 0.001-0.100 mol of the product and 0.001-0.100 mol of potassium carbonate in 30-100 mL of a mixed solution of tetrahydrofuran and absolute ethyl alcohol with a volume ratio of 7:3, transferring the mixed solution into a 50-300 mL flask, stirring the mixture in the flask at 100-2000 r/min, carrying out reflux reaction at room temperature for 2-10 h, stopping the reaction, carrying out suction filtration to remove solids, carrying out rotary evaporation at a vacuum degree of-0.09 MPa, a temperature of 40-80 ℃ and a rotating speed of 80-100 r/min for 20-60 min to remove the solvent, and carrying out dichloromethane column chromatography purification to obtain a yellow oily liquid;

step seven, 4-ethynyl-N, N-hexacosanylaniline preparation

Dissolving 5-100 mmol of p-iodoaniline and 5-100 mmol of 1-bromohexadecane in 10-200 mLN, N-dimethylformamide, then adding 5-100 mmol of potassium carbonate and 5-100 mmol of potassium iodide, placing the mixture in a 40KHz ultrasonic cleaning instrument for ultrasonic oscillation for 20-40 min, introducing argon gas for removing oxygen at 0.1-2L/min, carrying out water bath reflux reaction on a 20-500 mL flask containing the mixture at 80-150 ℃ for 15-24 h, plugging a reflux condenser tube opening with a rubber plug, carrying out suction filtration after the reaction to remove solids, extracting with 30-300 mL of water and 30-300 mL of dichloromethane to remove N, N-dimethylformamide, rotary evaporating at-0.09 MPa, 25-50 deg.C and 90r/min for 10-200 min to remove excessive solvent, then, using a mixture of dichloromethane and petroleum ether with a volume ratio of 1:6 as an eluent to carry out silica gel column chromatography purification, thus obtaining a product; dissolving 0.001-0.100 mol of the product in 50-100 mL of mixed solution of triethylamine and tetrahydrofuran in a volume ratio of 1:1, introducing argon gas at 0.1-2L/min, ultrasonically deoxidizing at 40KHz for 30min, then adding 0.001-0.100 mol of trimethylsilyl acetylene TMSA, 0.1-1.0 mmol of bis (triphenylphosphine) palladium dichloride and 0.2mmol of cuprous iodide, stirring in a 100-300 mL flask containing the mixture at a speed of 100-2000 r/min, carrying out reflux reaction in a water bath at 25-60 ℃ for 8-12 h, plugging a reflux condenser pipe orifice with a rubber plug, carrying out suction filtration after the reaction to remove solids, carrying out vacuum evaporation for 30min at a speed of-0.09 MPa, 40-80 ℃ and 80-100 r/min to remove more solvent, and then carrying out silica gel column chromatography purification by taking a mixture of dichloromethane and petroleum ether in a volume ratio of 1:6 as an eluent to obtain yellow liquid; dissolving 0.001-0.100 mol of product and 0.001-0.100 mol of potassium carbonate in 30-100 mL of a mixture of tetrahydrofuran and absolute ethyl alcohol with a volume ratio of 7:3, transferring the mixture into a 50-300 mL flask, stirring the mixture in the flask at 100-2000 r/min, carrying out reflux reaction at room temperature for 2-10 h, stopping the reaction, carrying out suction filtration to remove solids, carrying out rotary evaporation at a vacuum degree of-0.09 MPa, a temperature of 40-80 ℃ and a rotating speed of 80-100 r/min for 20-60 min to remove the solvent, and carrying out dichloromethane column chromatography purification to obtain a yellow oily liquid;

step eight, preparing white solid of polysiloxane side chain liquid crystal polymer by hydrosilylation reaction

Adding 0.10-5.00 mmol of liquid crystal monomer cholesterol p-alkenyloxybenzoate, 0.10-5.00 mmol of p-iodoallyloxy and 10-10 ppm of platinum catalyst into a flask for reaction, adding the mixture into 10-50 mL of toluene, evacuating the flask through a double-row pipe and filling nitrogen to remove oxygen in the flask, transferring the flask into an atmospheric pressure belt reflux microwave reactor with ultraviolet and Nd: YAG solid pulse laser, and irradiating the solution with Nd: YAG solid pulse laser, wherein the laser parameters are 1.06 mu m in wavelength, 1.2ms in pulse width, 0.2-6 mm in spot diameter, 2-40 Hz in repetition frequency and 1.0 × 10 in power density⁶W/cm²The light spot of the laser focus is 1-3 mm below the liquid level, and the irradiation time is 0.1-24 h; in the laser irradiation process, simultaneously starting an ultraviolet lamp for irradiation, wherein the wavelength of ultraviolet light is 190-400 nm, and the intensity is 5mW/cm²～15W/cm²The irradiation time is 0.1-24 h, the microwave heating is synchronously started while the laser and the ultraviolet irradiation are carried out, the microwave frequency is 2450MHz, the microwave power is 300-1000W, the microwave time is 0.1-24 h, the heating temperature is 25-100 ℃, the microwave generator is closed to reduce the temperature when the temperature in the microwave reactor exceeds the set temperature, the microwave generator is opened to increase the temperature when the temperature is lower than the set temperature, the reflux condensation is started, the opening of a reflux condensation pipe is blocked by a rubber plug to prevent air from entering, 200-500 mg of polymethyl hydrogen silicone oil PMHS is added under the condition of keeping vacuum after the reaction is finished, and then Nd: YAG solid pulse laser is used for irradiating the solution, wherein the laser parameters are 1.06 mu m in wavelength, 1.2ms in pulse width, 0.2-6 mm in spot diameter, 2-40 Hz in repetition frequency and 1.0 × 10⁶W/cm²The light spot of the laser focus is 1-3 mm below the liquid level, and the irradiation time is 0.1-24 h; in the laser irradiation process, simultaneously starting an ultraviolet lamp for irradiation, wherein the wavelength of ultraviolet light is 190-400 nm, and the power is 5mW/cm²～15W/cm²The irradiation time is 0.1-24 h; simultaneously starting microwave heating with microwave frequency of 2450MHz, microwave power of 300-1000W, microwave time of 0.1-24 h and heating temperature of 60-100 ℃ while irradiating with laser and ultraviolet,when the temperature in the microwave reactor exceeds the set temperature, the microwave generator is closed to reduce the temperature, and when the temperature is lower than the set temperature, the microwave generator is opened to increase the temperature; after the reaction is finished, taking out the reaction liquid, cooling the reaction liquid to room temperature, dropwise adding the reaction liquid into 20-500 mL of methanol under the condition of mechanical stirring at 100-1000 r/min, centrifugally separating at 7000r/min, re-dissolving the solid phase substance into 20-500 mL of chloroform, precipitating with 20-500 mL of methanol to remove unreacted raw materials, and drying at 70-80 ℃ for 6-72 hours to obtain white solid of the polysiloxane side chain liquid crystal polymer;

step nine, preparation of polysiloxane side chain liquid crystal polymer modified by triple bond

Dissolving 50-150 mg of liquid crystal polymer prepared by hydrosilylation reaction and 0.10-1.00 mmol of p- (dibutylamino) phenylacetylene or 4-ethynyl-N, N-hexacosanylaniline in 5-30 mL of triethylamine and tetrahydrofuran solution with a volume ratio of 1:1, introducing 0.1-2L/min of argon, ultrasonically deoxidizing for 30min under the condition of 40KHz, adding 0.1-1.0 mmol of bis (triphenylphosphine) palladium dichloride and 0.1-1.0 mmol of cuprous iodide, stirring at 100-2000 r/min, refluxing and reacting in water bath at 40 ℃ for 5-20 h, centrifugally separating at 7000r/min to remove solids, dropwise adding the liquid product into 100-500 mL of methanol solution under stirring at a rotating speed of 100-2000 r/min, centrifugally separating at 7000r/min, redissolving the precipitate in 100-500 mL of trichloromethane, precipitating with 20-500 mL of methanol to remove unreacted raw materials, obtaining polysiloxane side chain liquid crystal polymer modified by triple bonds;

step ten, click reaction preparation of click-modified polysiloxane side chain liquid crystal polymer

And (4) adding the polysiloxane side chain liquid crystal polymer obtained in the step nine into 5-50 mL of methanol, adding a click chemistry modified micromolecule monomer into the other 5-50 mL of methanol, and mixing the two solutions to prepare the click modified polysiloxane side chain liquid crystal polymer through click reaction.

In the preparation of the p-alkenyloxybenzoic acid, the p-alkenyloxybenzoic acid is obtained by reacting ethyl p-hydroxybenzoate with allyl bromide.

In the preparation of the p-alkenyloxybenzoic acid, the alkene bromine is one or any combination of two or more than two of 3-bromine-1-propylene, 5-bromine-1-pentene and 13-bromine-1-tridecene.

In the preparation of the liquid crystal polymer by the hydrosilylation reaction, when the polymethyl hydrogen-containing silicone oil reacts with two liquid crystal monomers, one of the two liquid crystal monomers is 0, but not both of the two liquid crystal monomers are 0.

In the preparation of the liquid crystal monomer-p-alkenyloxy benzoic acid cholesterol ester, the p-alkenyloxy benzoic acid cholesterol ester is obtained by esterifying p-alkenyloxy benzoic acid and cholesterol.

In the preparation of the liquid crystalline monomer p-alkenyloxy benzoic alcohol ester, the p-alkenyloxy benzoic alcohol ester is obtained by esterifying p-alkenyloxy benzoic acid and R-OH, wherein R is selected from

One kind of (1).

The solvent used in the polysiloxane side chain liquid crystal polymer prepared by click modification is dichloromethane, and the small molecular monomer is one, two or more of 7,7,8, 8-tetracyanoquinodimethane, tetracyanoethylene, 2,3,5, 6-tetrafluoro-7, 7',8,8' -tetracyanoquinodimethane, wherein the dichloromethane is 5-30 mL, the 7,7,8, 8-tetracyanoterephthalquinodimethane is 10-100 mg, the 2,3,5, 6-tetrafluoro-7, 7',8,8' -tetracyanoquinodimethane is 10-100 mg, and the tetracyanoethylene is 1-50 mg.

The polysiloxane side chain liquid crystal polymer prepared by click modification has a polysiloxane main chain, has good surface energy, mechanical and thermal stability, and can graft side chains with different properties through hydrosilylation reaction, so that the polysiloxane side chain liquid crystal polymer shows liquid crystallinity and nonlinear optical effect.

According to the polysiloxane side chain liquid crystal polymer prepared by click modification, the grafted side chain is a chiral compound named as p-alkenyloxy benzoic acid cholesterol ester, wherein m is an integer larger than 3, so that linear polysiloxane can show liquid crystallinity.

According to the linear polysiloxane displaying liquid crystallinity, the grafted side chain is a compound of substitution termination of achiral different polar groups, and the introduction of the side chain can achieve that the polysiloxane side chain liquid crystal polymer has different phase structures, wherein p is an integer larger than or equal to 3, and different polar groups are cyano-group, methoxy-group and phenyl-group structures.

According to the linear polysiloxane for displaying the nonlinear optical effect, the grafted side chain of the linear polysiloxane is an organic conjugated group modified by click chemistry, and the linear polysiloxane has a good chromophore structure for an acceptor after click modification, so that the linear polysiloxane displays good third-order nonlinear optical effect, wherein q is an integer larger than or equal to 3, and n is an integer from 0 to 16.

[ advantages and effects of the invention ]: the invention provides a preparation method of a click-modified polysiloxane side chain liquid crystal polymer, which has the following advantages and beneficial effects: 1. through sulfydryl-vinyl click reaction, polymethyl hydrogen-containing silicone oil is used as a main chain, a liquid crystal monomer is grafted to the main chain under the combined catalysis of ultraviolet light, laser and microwave to synthesize polysiloxane side chain liquid crystal polymer, microwave irradiation, ultraviolet and laser technical means are selectively or intensively comprehensively applied in the synthesis process, the obtained product is uniform and high in purity, the catalyst is easy to remove, the microwave heating reaction rate is high, the temperature hysteresis effect is avoided, the ultraviolet irradiation energy temperature is reduced, the laser energy is concentrated and pollution is avoided, and the technical foundation is laid for further exploring the structure and performance of subsequent products; 2. by changing the use types of the liquid crystal monomers and the grafting molar ratio of the two liquid crystal monomers, the polysiloxane side chain liquid crystal polymer structure can be adjusted, so that the polysiloxane side chain liquid crystal polymer structure has different properties, and guarantee and power are provided for promoting the application of the materials in the fields of liquid crystal displays, biological medicines and the like.

[ description of the drawings ]

FIG. 1 is a reaction scheme of the synthesis of polysiloxane side chain liquid crystalline polymer according to the present invention

FIG. 2 is a schematic view of the structure of the laser, UV and microwave combination device used in the present invention (with reflux condenser)

FIG. 3 is a schematic diagram showing the structure of the laser, UV and microwave combination device used in the present invention (glass four-port connecting tube, one of which is connected to a flask, and the other three ports are connected to a reflux condenser, a stirring paddle, a separating funnel, an argon tube or used for air evacuation and vacuum evacuation as required)

[ detailed description ] embodiments

For clearly explaining the technical characteristics of the scheme, the patent of the invention is explained in detail by the specific implementation mode and the attached drawings.