Liquid crystal grafting modified butylbenzene transparent anti-impact resin and preparation method thereof

Abstract

The invention belongs to the field of synthesis and modification of butylbenzene resin, and particularly discloses liquid crystal grafting modified butylbenzene transparent anti-impact resin and a preparation method thereof. The liquid crystal grafting modified butylbenzene transparent anti-impact resin is a grafted copolymer of a silicon-hydrogen group-containing functionalized butylbenzene transparent anti-impact resin and a cholesteric liquid crystal monomer, and the mass ratio of the silicon-hydrogen group-containing functionalized butylbenzene transparent anti-impact resin to the cholesteric liquid crystal monomer is (100-500): 1; the styrene-butadiene transparent anti-impact resin with Si-H active sites reacts with the cholesteric liquid crystal functional monomer with the functionalized terminal vinyl, so that the cholesteric liquid crystal groups are introduced into the styrene-butadiene transparent anti-impact resin, and the prepared styrene-butadiene transparent anti-impact resin is good in optical performance and mechanical performance, excellent in material compatibility and good in mechanical property. And the market prospect is wide.

Description

Technical Field

[0001] The present invention belongs to the field of synthesis and modification of styrene-butadiene resins, and particularly relates to a class of liquid crystal graft-modified styrene-butadiene transparent impact-resistant resins and a preparation method thereof. Background Art

[0002] Styrene-butadiene transparent impact-resistant resin, abbreviated as K resin, is a lithium-based block copolymer produced by an anionic solution polymerization process using styrene and butadiene as monomers and alkyl lithium as an initiator. It has both high transparency and good impact resistance and excellent processing properties, and plays an important role in the fields of packaging, plastics, medical appliances, toys, furniture, instruments, etc. In addition, K resin is currently widely used for modification in industry and can be blended and modified with a variety of plastics, making it play a huge potential in the field of engineering plastics processing. For example, blending K resin with high-impact polystyrene (HIPS) can endow the material with both appropriate impact strength and rigidity, as well as good processing properties. When the tensile strength and heat resistance of its products are comparable to those of HIPS, the gloss and elongation are better than those of pure HIPS. In addition, when the injection molding contains 30%-70% of K resin, the notched impact strength is better than that of pure K resin; the blend of K resin and styrene-acrylonitrile copolymer (SAN) has good transparency, stiffness, heat resistance and very good gloss. When modified with a small amount of SAN (<20%), the material retains the high impact strength and good elongation of K resin while increasing rigidity, hardness and heat resistance. When SAN is modified with a small amount of K resin, the material has better toughness than SAN, and the hardness, heat resistance and rigidity are hardly reduced; the blend of K resin and polypropylene (PP) is mainly used for pearlescent injection molded products, which not only have high gloss, but also have relatively good rigidity and hardness, and a long hinge life. When the ratio of K resin / PP is in the range of 98 / 2 to 30 / 70, the blend has good elongation, rigidity, low-temperature impact strength, heat resistance and foldability. Especially in the composition range of 95 / 5 to 70 / 30, the inherent elongation and foldability of the blend are improved compared with those of K resin, and the improvement of the low-temperature impact strength is the most obvious, and the heat resistance and rigidity are also significantly improved; the impact resistance of polycarbonate (PC) is well known, but after low temperature and thermal aging, thick PC parts are particularly sensitive to notched impact fracture, while blending PC with a lower melt index and K resin can improve the notched impact strength. In addition, the processing of this blend is easier than that of PC and can be molded at a lower temperature, and it is also competitive in price. However, with the rapid development of functional polymer materials, the demand for the diversification of polymer structure and properties is also rising continuously. The functional modification research of K resin is relatively less, which greatly limits its application scope.

[0003] In order to overcome the problems of poor mechanical and optical properties of styrene-butadiene rubber, how to modify styrene-butadiene rubber, expand its application range, and enhance its competitiveness in application fields such as medical products and instruments is a technical problem that needs to be solved urgently. Summary of the invention

[0004] In view of the problems existing in the prior art, the present invention provides a type of liquid crystal grafted modified styrene butadiene transparent impact-resistant resin and a preparation method thereof. The present invention adopts active anion solution polymerization to prepare the styrene butadiene transparent impact-resistant resin, and at the same time, quantitatively and positionally introduces silicon-containing group-functionalized 1,1-diphenylethylene derivatives in the preparation process of the styrene butadiene transparent impact-resistant resin, and the styrene butadiene transparent impact-resistant resin with Si-H active sites reacts with the terminal vinyl-functionalized cholesterol liquid crystal functional monomer, thereby introducing the cholesterol liquid crystal group into the styrene butadiene transparent impact-resistant resin. The prepared styrene butadiene transparent impact-resistant resin has good optical and mechanical properties, excellent material compatibility, and improves the market competitiveness of the material in the application fields of medical products, instruments and meters, etc.

[0005] In the first aspect, the present invention provides a type of liquid crystal grafted modified styrene butadiene transparent impact-resistant resin, wherein the liquid crystal grafted modified styrene butadiene transparent impact-resistant resin is a graft copolymer of a styrene butadiene transparent impact-resistant resin functionalized with a silicon group and a cholesteric liquid crystal monomer, wherein the mass ratio of the styrene butadiene transparent impact-resistant resin functionalized with a silicon group to the cholesteric liquid crystal monomer is (100-500):1;

[0006] The structural formula of the cholesteric liquid crystal monomer is:

[0007]

[0008] Wherein, R represents an alkane chain or an alkane chain connected to an oxygen atom and having a carbonyl group at the end, and the number of carbon atoms is 1-18; M represents a vinyl group, an alkynyl group or a hydroxyl group.

[0009] Furthermore, the number average molecular weight (M n )Range: 2~300×10 4 g / mol, molecular weight distribution index (PDI) range of 1.02-1.70; the number average molecular weight (M n ) ranges from 1 to 150×10 4 g / mol, and the molecular weight distribution index (PDI) ranges from 1.02 to 1.60

[0010] Further, the silicon group-functionalized styrene-butadiene impact transparent resin is a block copolymer of styrene (St), butadiene (Bd), isoprene (Ip), and a silicon group-functionalized 1,1-diphenylethylene derivative (Si-DPE); based on the mass of the silicon group-functionalized styrene-butadiene impact transparent resin being 100%, the styrene content is 45% to 90%, preferably 50% to 85%, the content of the silicon group-functionalized 1,1-diphenylethylene derivative is 0.2% to 2%, the isoprene (Ip) content is 0 to 15%, and the balance is butadiene (Bd).

[0011] Further, the silicon group-functionalized 1,1-diphenylethylene derivative is distributed at least at one position of the chain initiation end, the chain end, and the chain middle of the silicon group-functionalized styrene-butadiene impact transparent resin.

[0012] Further, the sequence structure of styrene, butadiene, and isoprene in the silicon group-functionalized styrene-butadiene transparent impact resin includes, but is not limited to, a block structure, a gradient block structure, and a random block structure.

[0013] Further, the silicon group-functionalized 1,1-diphenylethylene derivative is selected from diphenylethylene derivatives containing a silicon hydride group, a siloxane group / silicon hydride group, and a silicon hydride group / amine group; the silicon hydride group, the siloxane group / silicon hydride group, and the silicon hydride group / amine group are connected to the para-position, meta-position, or ortho-position of the phenyl group in the 1,1-diphenylethylene derivative.

[0014] The 1,1-diphenylethylene derivatives containing a silicon hydride group, a siloxane group / silicon hydride group, and a silicon hydride group / amine group are selected from:

[0015] (1) The general range of the monosilicon hydride group DPE derivative monomer is 1-[4-R2 group phenyl]-1-phenylethylene, and the general range of the disilicon hydride group DPE derivative monomer is 1,1-di[4-R2 group phenyl]ethylene, wherein R2 is a silicon hydride group, selected from dimethylsilyl, diethylsilyl, dipropylsilyl, diisopropylsilyl, di-tert-butylsilyl; the best range is 1-[4(dimethylsilyl)phenyl]1-phenylethylene, 1,1-di[4-(dimethylsilyl)phenyl]ethylene;

[0016] (2) The monomer of the siloxyl group / silyl hydride group DPE derivative generally ranges from 1-[4-R1 group phenyl]-1-[R2-group phenyl] ethylene, where R1 is a siloxyl group selected from trimethoxysilyl, triethoxysilyl, triisopropoxysilyl, tri-tert-butoxysilyl, dimethylmethoxysilyl, diethylmethoxysilyl, and R2 is a silyl hydride group selected from dimethylsilyl hydride, diethylsilyl hydride, dipropylsilyl hydride, diisopropylsilyl hydride, di-tert-butylsilyl hydride; the optimal range is 1-[4-(triisopropoxysilyl)phenyl]-1-[4-(dimethylsilyl hydride)phenyl] ethylene;

[0017] (3) The monomer of the silyl hydride group / amino group DPE derivative generally ranges from 1-[4-R2 group phenyl]-1-[4-R3 group phenyl] ethylene, where R2 is a silyl hydride group selected from dimethylsilyl hydride, diethylsilyl hydride, dipropylsilyl hydride, diisopropylsilyl hydride, di-tert-butylsilyl hydride, and R3 is an amino group selected from N,N-dimethylamino, N,N-diethylamino, N,N-di-tert-butylamino; the optimal range is 1-[4-(dimethylsilyl hydride)phenyl]-1-[4-(N,N-dimethylamino)phenyl] ethylene;

[0018] Furthermore, the monomers such as styrene, butadiene, isoprene or their mixture are added and reacted step by step. By adjusting the monomer addition sequence, block structures, gradient block structures, and random block structures can be formed.

[0019] In the second aspect, the present invention provides a preparation method of a liquid crystal graft-modified styrene-butadiene transparent impact-resistant resin, including the following steps:

[0020] S1. In an anhydrous and oxygen-free glove box, add the silicon group-functionalized styrene-butadiene transparent impact-resistant resin, cholesteric liquid crystal monomer, and solvent into a reactor, and stir until the solid is completely dissolved;

[0021] S2. Add a catalyst to the reactor, and seal and stir the reaction for at least 24 h under the condition of 20-60 °C; after the reaction is completed, a white solid product is obtained through post-treatment, which is the liquid crystal graft-modified styrene-butadiene transparent impact-resistant resin;

[0022] The molar ratio of the silicon group in the silicon group-functionalized styrene-butadiene transparent impact-resistant resin to the cholesteric liquid crystal monomer is 1:1-1:2;

[0023] The addition amount of the solvent is: 5-30 ml of solvent is added per 100 mg of the silicon group-functionalized styrene-butadiene transparent impact-resistant resin.

[0024] The solvent is selected from at least one of benzene, toluene, hexane, and cyclohexane;

[0025] The grafting method is selected from hydrosilylation reaction or dehydrogenative coupling reaction of organosilanes. The catalyst for the hydrosilylation reaction is Karstedt catalyst, and the catalysts for the dehydrogenative coupling reaction of organosilanes are selected from anionic iridium complexes, rhodium catalysts, cobalt catalysts, and chiral bisphosphine ligands.

[0026] Furthermore, the preparation method of the silicon group-functionalized styrene-butadiene transparent impact-resistant resin is as follows:

[0027] S1. Under the protection of nitrogen or argon, a metered non-polar solvent, a polarity regulator, and a silicon group-functionalized 1,1-diphenylethylene derivative monomer are added to a polymerization reactor, adjusted to a set temperature, and an alkyllithium initiator is added according to the measurement. The initiation temperature range is 10-90°C, and the initiation time is 3-10 h.

[0028] S2. Monomers styrene (St), butadiene (Bd), and isoprene (Ip) are added in a set order, and the reaction temperature is controlled at 30-110°C, and the reaction time is 1-10 h.

[0029] S3. To prepare the silicon group-functionalized styrene-butadiene impact-resistant transparent resin, specifically select one of the following three operations:

[0030] S31. A terminator and an antioxidant are added, stirred evenly, and then discharged to obtain a silicon group-functionalized styrene-butadiene impact-resistant transparent resin with a silicon group at the chain initiation end.

[0031] S32. After the monomer reaction is completed, a silicon group-functionalized 1,1-diphenylethylene derivative monomer is added to the polymerization reactor for capping. The reaction temperature is 50-110°C, and the reaction continues for 1-3 h. A terminator and an antioxidant are added, stirred evenly, and then discharged to prepare a silicon group-functionalized styrene-butadiene impact-resistant transparent resin with silicon groups at both the chain initiation end and the chain termination end.

[0032] S33. A coupling agent is added to the polymerization reactor, and the reaction continues for 0.5-5 h. The reaction temperature is controlled at 30-110°C. A terminator and an antioxidant are added, stirred evenly, and then discharged to obtain a silicon group-functionalized styrene-butadiene impact-resistant transparent resin, in which both the chain initiation end and the chain termination end have silicon group-functionalized 1,1-diphenylethylene derivative groups.

[0033] Furthermore, in step S2, on the basis of adding styrene (St), butadiene (Bd), and isoprene (Ip) to the polymerization reactor, a silicon group-functionalized 1,1-diphenylethylene derivative monomer is added to prepare a star-shaped styrene-butadiene transparent impact-resistant resin with silicon groups at both the chain ends and the chain middle.

[0034] Alternatively, the preparation method of the silicon group-functionalized styrene-butadiene impact-resistant transparent resin includes the following steps:

[0035] Under the protection of nitrogen or argon, measured non-polar solvent and polar regulator are added into the polymerization reactor, and the temperature is adjusted to the set temperature. Then, alkyl lithium initiator is added according to the measurement, and the initiation temperature range is 10-90 °C, and the initiation time is 3-10 h. Then, the reaction monomers styrene (St), butadiene (Bd), and isoprene (Ip) are added, and the reaction temperature is controlled at 30-110 °C, and the reaction time is 1-10 h. Then, a linear coupling agent is added into the polymerization reactor, and the reaction continues for 0.5-5 h, and the reaction temperature is controlled at 30-110 °C. A silane group-functionalized 1,1-diphenylethylene derivative monomer is added to cap the polymerization reactor, and the reaction temperature is 50-110 °C, and the reaction continues for 1-3 h. After adding a terminator and an antioxidant and stirring evenly, the product is discharged to obtain the styrene-butadiene impact transparent resin with a silane group-functionalized chain end; wherein the chain termination end has a silane group-functionalized 1,1-diphenylethylene derivative group.

[0036] Further, the molar ratio of the total amount of the silane group-functionalized 1,1-diphenylethylene derivative added in each step to the alkyl lithium initiator is (1-5):1.

[0037] Further, the molar ratio of the polar regulator to the alkyl lithium initiator is (0.5-5):1;

[0038] Further, the mass ratio of styrene (St), butadiene (Bd), and isoprene (Ip) is (0.8-1.6):1:(0-0.3).

[0039] Further, the molar ratio of the coupling agent to the alkyl lithium initiator is (1-3):1; the molar ratio of the terminator to the alkyl lithium initiator is (1-10):1.

[0040] Further, the mass fraction of the three reaction monomers styrene (St), butadiene (Bd), and isoprene (Ip) in the solution is 5-20%.

[0041] Further, the mass ratio of the antioxidant to the three reaction monomers styrene (St), butadiene (Bd), and isoprene (Ip) is 1:(1000-10000), and the mass ratio of the antioxidant to the three reaction monomers styrene (St), butadiene (Bd), and isoprene (Ip) is 1:(1000-10000).

[0042] Further, the silane group-functionalized 1,1-diphenylethylene derivative is selected from diphenylethylene derivatives containing siloxane groups, silicon hydride groups, and siloxane groups / silicon hydride groups.

[0043] Further, the non-polar solvent is selected from benzene, toluene, ethylbenzene, xylene, pentane, hexane, heptane, octane, cyclohexane, decalin, methylcyclohexane, mixed aromatic hydrocarbons (such as mixed xylene), and mixed aliphatic hydrocarbons (such as raffinate oil), and preferably hexane, cyclohexane, pentane, methylcyclohexane and their mixed solvents;

[0044] Further, the preferred mass fraction range of the monomer in the solvent is 8-15%.

[0045] Further, the alkyl lithium initiator is n-butyl lithium and sec-butyl lithium.

[0046] Further, the polar regulator is tetrahydrofuran, 2,2-bis(2-tetrahydrofuryl)propane, 2,2-bis(5-methyl-2-tetrahydrofuran)propane, ethyltetrahydrofurfuryl ether, tetramethylethylenediamine, diethylene glycol diethyl ether; Whether to use a polar additive is determined according to the designed microstructure and sequence structure.

[0047] Further, the coupling agent can be a linear coupling agent or a star coupling agent. The linear coupling agent is selected from R(CH3)2Cl2, 1,2-dichloroethane or 1,2-dibromoethane, where R is a metal atom selected from metal elements such as silicon (Si), tin (Sn), lead (Pb), titanium (Ti), and germanium (Ge), and preferably dimethyldichlorosilane; The star coupling agent is selected from Si(R1) n (R2) m 、Sn(R1) n (R2) m 、Ti(R1) n (R2) m 、Pb(R1) n (R2) m 、Ge(R1) n (R2) m 、Zr(R1) n (R2) m or a mixture of one or more coupling agents, where n + m = 3, 4, 6, 8; R1 is one or two of the halogen elements F, Cl, Br, I; R2 is a hydrocarbon group with 2-20 carbon atoms, and R can be an alkyl group, an aryl group or a 1,1-diphenylethylene derivative.

[0048] Further, the cholesteric liquid crystal monomer is prepared by the following method:

[0049] Dissolve p-hydroxybenzoic acid in absolute ethanol, prepare an aqueous solution of potassium hydroxide and potassium iodide and gradually add it dropwise to the p-hydroxybenzoic acid solution, and stir the reaction at room temperature; then add the halogenated hydrocarbon dropwise to the system, stop after heating under reflux for more than 5 h. After the reaction is completed, remove the solvent under reduced pressure and wash the crude product with dilute hydrochloric acid several times; filter the system under reduced pressure, dry the filter cake, and recrystallize with hot ethanol to obtain a white solid.

[0050] Dissolve the white solid in the acyl chloride, stop the reaction after heating under reflux for more than 3 h. Remove the excess acyl chloride through a vacuum distillation device to obtain a yellow solution. Dissolve cholesterol in a mixed solution of dichloromethane and pyridine, slowly add it dropwise to the above yellow solution, and stop the reaction after heating under reflux for 3 h. After the reaction is completed, remove the solvent by rotary evaporation under reduced pressure to obtain a pale yellow powder, acidify the system overnight and recrystallize with hot ethanol to obtain cholesterol-based liquid crystal monomers with vinyl or alkynyl or hydroxyl groups at the ends.

[0051] The beneficial effects of the present invention are as follows:

[0052] The present invention first synthesizes a main chain of a silicon group-functionalized styrene-butadiene transparent impact-resistant resin with controllable and diverse structures through anionic living polymerization method, introduces cholesterol-based liquid crystal monomers into the polymer by an efficient post-polymerization modification method, prepares a series of liquid crystal graft-modified styrene-butadiene transparent impact-resistant resins. The prepared styrene-butadiene resins have good optical and mechanical properties, excellent material compatibility, and improve the market competitiveness of materials in application fields such as medical products, instruments and meters, providing an important basis for the functional modification of styrene-butadiene transparent impact-resistant resins and their applications in new fields.

[0053] (1) Injection molding of styrene-butadiene resins

[0054] The injection molding instrument is a Haake minijet pro injection molding machine produced by Thermo Fisher Scientific. The barrel temperature is 160 - 170 °C, the mold temperature is 40 °C, the pressure is 300 bar or 350 bar, the injection holding time and the mold holding time are both 10 s. The injection specimens are left standing at room temperature for 24 h to fully release the internal stress and then used.

[0055] (2) Melt flow rate test

[0056] The test instrument is an MFI-1211 melt flow rate tester produced by Jinjian Testing Instruments Co., Ltd. The test refers to the ISO 1133 standard. The instrument load is 2.16 kg, the automatic cutting interval time is 10 s or 20 s, and the number of cutting times is ten times. When testing, heat the instrument barrel to 190 °C and keep it constant, fill the resin sample into the barrel and let it stand for 3 min until the sample melts, evenly press out the sample with the load, collect the samples after each cutting and weigh them, and take the average value of the final results.

[0057] (3) Shore hardness test

[0058] The testing instrument is the LX-D-Y digital display Shore hardness tester produced by Langrun Technology Co., Ltd. The dimensions of the test specimens are the same as those used in the bending test. The test is carried out in accordance with ISO 868 standard. During the test, place the specimen on a firm plane, vertically press the indenter of the hardness tester into the surface of the specimen and ensure that the foot of the indenter is in full contact with the specimen. The applied pressure is 1 kg. Read the hardness value 15 s after the foot of the indenter is in full contact with the specimen. Conduct five experiments for each sample, and take the average value of the final results.

[0059] (4) Vicat softening point test

[0060] The testing instrument is the VTM1600 microcomputer-controlled heat distortion and Vicat softening tester produced by SANS Testing Machine Co., Ltd. The dimensions of the test specimens are the same as those used in the bending test. The test is carried out in accordance with ISO 306 standard. During the test, place the sample on the test bench and adjust the position of the indenter to contact the surface of the sample. Start the test program and heat the sample according to the set conditions (heating rate: 120 °C / h, conditioning temperature: 50 °C), while controlling the indenter to move downward at a constant rate. Record the temperature value when the indenter penetrates the surface of the sample to a predetermined depth. Conduct five experiments for each sample, and take the average value of the final results.

[0061] (5) Optical property test

[0062] The testing instrument is the YH1200 haze meter produced by 3NH Technology Co., Ltd. The test is carried out in accordance with ASTM D1003 standard, and the instrument calibration is carried out in accordance with JJF 1303-2011 standard. The illumination light source is a 400 - 700 nm combined LED light source. During the test, ensure that the surface of the sample is flat, free of foreign objects, scratches, oil stains and dust, and has no visible defects and particles. The test specimens used are prepared by injection molding process, with dimensions of (30 ± 2) mm × (30 ± 2) mm × (1 ± 0.1) mm. Conduct five experiments for each sample, and take the average value of the final results.

[0063] (6) Mechanical property test

[0064] The tensile and flexural property testing instrument is a 5567A material testing machine produced by Instron. For the tensile test, it refers to ISO 527 standard, with a tensile rate of 5 mm / min, an effective distance of 25 mm, and the shape and size of the specimen being an ISO 527-2-5A standard dumbbell-shaped specimen. Record the tensile strength, elongation at break, and Young's modulus of the corresponding specimen. Conduct five experiments for each sample, and take the median value as the final result. For the flexural test, it refers to ISO 178 standard, with a flexural rate of 2 mm / min, a span of 64 mm, and the specimen size being (80±2) mm×(10±2) mm×(4±2) mm. Record the flexural modulus and maximum flexural stress of the corresponding specimen. Conduct five experiments for each sample, and take the median value as the final result. The Izod notched impact property testing instrument is a GT-7045-ALN impact testing machine produced by Gotech. Use a GT-7015-A3 sample grinding and leveling testing machine produced by Gotech to create a notch on the surface of the specimen, with a notch depth of (2±0.2) mm. The test refers to ISO 180 / A standard, with a pendulum specification of 5.5 J, a span of 62 mm, a pendulum angle of (150±0.2) mm, and the specimen size being the same as that used in the flexural experiment. Record the notched impact strength of the corresponding specimen. Conduct five experiments for each sample, and take the average value as the final result.

[0065] (7) Nuclear magnetic resonance hydrogen spectrum ( 1 H-NMR)

[0066] The testing instrument is a Varian DLG400 MHz nuclear magnetic resonance spectrometer produced by Varian, with tetramethylsilane (δ = 0 ppm) as the internal standard. Dissolve an appropriate amount of the sample to be tested (5 - 10 mg) in deuterated chloroform and conduct the test at room temperature. This test method is used to determine the molecular structures of monomers and polymers.

[0067] (8) Gas chromatography / triple quadrupole mass spectrometry (GC-MS)

[0068] The testing instrument is a 7000B Triple Quadrupole gas chromatography / triple quadrupole mass spectrometry produced by Agilent. This test method is used for the structural analysis of monomers.

[0069] (9) Gel permeation chromatography (GPC)

[0070] The testing instrument is a Waters 1515 chromatographic system (equipped with two separation columns, HT4 and HT5, and a 2414 differential refractometer) produced by Waters. Use THF as the mobile phase, with a testing flow rate of 1.0 ml / min, a column temperature of 35, and PS as the instrument calibration standard sample. This test method is used to determine the molecular weight and its distribution of polymers.

[0071] (10) Differential Scanning Calorimeter (DSC)

[0072] The test instrument is TA Q2000 produced by TA Company. The test is carried out under nitrogen protection, and the heating and cooling rates are both 10 / min, and the test temperature range is -100 - 160 °C. This test method is used to determine the T of the polymer g .

[0073] (11) Scanning Electron Microscope (SEM)

[0074] The test instrument is SEM5000 scanning electron microscope produced by Guoyi Quantum Co., Ltd. The acceleration voltage range is 20V - 30kV, and the resolution is less than or equal to 1.0 nm. This test method is used to observe the morphology of the impact fracture surface of the spline. Before the test, a conductive film is plated on the surface of the spline notch by a Q150T coating instrument produced by Quorum Company to improve the imaging quality of the SEM. Detailed implementation mode

[0075] Example 1:

[0076] Step S1, synthesize a linear styrene-butadiene transparent impact-resistant resin with a silicon-hydrogen group-functionalized chain-initiating end:

[0077] Under the protection of inert gas, add 2500 g of methylcyclohexane, 0.15 g of ethyltetrahydrofurfuryl ether and 0.15 g of 1-(4-dimethylsilylphenyl)-1-phenylethylene monomer into the polymerization reactor, adjust to the set temperature, add 2 ml of alkyllithium initiator, the initiation temperature is 20 °C, then add monomers styrene, butadiene or their mixture in the set order, add monomers St (80 g), Bd (25 g), Ip (10 g) in sequence, the reaction temperature is 30 °C, after the monomers react, add 1 g of terminator, and finally add N,N'-diphenyl-p-phenylenediamine (0.08 g), stir evenly and then discharge to obtain a linear styrene-butadiene transparent impact-resistant resin with a silicon-hydrogen group-functionalized chain-initiating end, the number-average molecular weight (M n ) is 1×10 4 g / mol, and the molecular weight distribution index (PDI) range is 1.02;

[0078] Step S2, synthesize a cholesteric liquid crystal monomer:

[0079] Dissolve p-hydroxybenzoic acid in absolute ethanol, prepare an aqueous solution of potassium hydroxide and potassium iodide and gradually add it dropwise to the p-hydroxybenzoic acid solution, stir and react at room temperature; then add the halogenated hydrocarbon dropwise to the system, stop after heating under reflux for 5 h. After the reaction is completed, the solvent is removed under reduced pressure and the crude product is washed several times with dilute hydrochloric acid; the system is filtered under reduced pressure, the filter cake is dried, and white solid is obtained after recrystallization with hot ethanol;

[0080] Dissolve the white solid in the acyl chloride, heat under reflux for 3 h and then stop. Remove the excess acyl chloride through a vacuum distillation device to obtain a yellow solution. Dissolve cholesterol in a mixed solution of dichloromethane and pyridine, slowly drop it into the above yellow solution, heat under reflux for 3 h and then stop. After the reaction is completed, remove the solvent by rotary evaporation under reduced pressure to obtain a pale yellow powder. Acidify the system overnight and then recrystallize it with hot ethanol to obtain a cholesterol-based liquid crystal monomer with a vinyl end;

[0081] Step S3, synthesize a cholesterol-based liquid crystal graft-modified styrene-butadiene transparent impact-resistant resin:

[0082] In an anhydrous and anaerobic glove box, add 100 g of a linear styrene-butadiene transparent impact-resistant resin with a silicon hydride group at the chain initiation end and 5 g of a cholesterol-based liquid crystal monomer to a reactor, pour in 5 L of toluene solvent, stir until the solid is completely dissolved, and then add 0.1 g of a Karstedt catalyst; seal the system and stir for reaction for 24 h. After the reaction is completed, perform post-treatment to obtain a white solid product, and the number-average molecular weight (M n ) is 15×10 4 g / mol, the molecular weight distribution index (PDI) ranges from 1.17, the transparency is 95%, the haze is 8%, and the impact strength is 12 kJ / m 2 .

[0083] Example 2:

[0084] Step S1, synthesize a linear styrene-butadiene transparent impact-resistant resin with a silicon hydride group at the chain termination end:

[0085] Under the protection of an inert gas, add 1000 g of toluene and 0.1 g of tetrahydrofuran to a polymerization reactor, add 1 ml of an alkyl lithium initiator, the initiation temperature is 40 °C, and then add monomers styrene, butadiene or their mixture in a set order. The reaction temperature is 50 °C. After the monomers react, add monomers St (50 g), Bd (10 g), and Ip (5 g) in sequence. Add 0.1 g of 1-[4-(triisopropoxysilyl)phenyl]-1-[4-(dimethylsilylhydrido)phenyl]ethylene monomer to cap the polymer, and finally add 2 g of a terminator and 6-ethoxy-2,2,4-trimethyl-1,2-dihydroquinoline (0.1 g) antioxidant. Stir evenly and then discharge to obtain a linear styrene-butadiene transparent impact-resistant resin with a silicon hydride group at the chain termination end, and the number-average molecular weight (M n ) is 30×10 4 g / mol, and the molecular weight distribution index (PDI) ranges from 1.25;

[0086] Step S2, synthesize a cholesterol-based liquid crystal monomer:

[0087] Dissolve p-hydroxybenzoic acid in absolute ethanol, prepare an aqueous solution of potassium hydroxide and potassium iodide and gradually add it dropwise to the p-hydroxybenzoic acid solution, and stir the reaction at room temperature; then add the halogenated hydrocarbon dropwise to the system, stop after heating under reflux for 8 h. After the reaction is completed, remove the solvent under reduced pressure and wash the crude product with dilute hydrochloric acid several times; filter the system under reduced pressure, dry the filter cake, and recrystallize with hot ethanol to obtain a white solid;

[0088] Dissolve the white solid in the acyl chloride, stop the reaction after heating under reflux for 5 h. Remove the excess acyl chloride through a vacuum distillation device to obtain a yellow solution. Dissolve cholesterol in a mixed solution of dichloromethane and pyridine, slowly add it dropwise to the above yellow solution, and stop the reaction after heating under reflux for 5 h. After the reaction is completed, remove the solvent by rotary evaporation under reduced pressure to obtain a pale yellow powder, acidify the system overnight and recrystallize with hot ethanol to obtain a cholesterol-based liquid crystal monomer with an alkyne group at the end;

[0089] Step S3, synthesize cholesterol-based liquid crystal graft-modified styrene-butadiene transparent impact-resistant resin:

[0090] In an anhydrous and oxygen-free glove box, add 150 g of linear styrene-butadiene transparent impact-resistant resin with a silicon hydride group at the chain termination end and 10 g of cholesterol-based liquid crystal monomer to the reactor, pour in 10 L of hexane solvent, stir until the solid is completely dissolved, and then add 5 g of rhodium catalyst; seal the system and stir the reaction for 26 h, and obtain a white solid product after post-treatment; the number average molecular weight (M n ) is 76×10 4 g / mol, the molecular weight distribution index (PDI) ranges from 1.37; the transparency is 80%, the haze is 10%, and the impact strength is 16 kJ / m 2 .

[0091] Example 3:

[0092] Step S1, synthesize linear styrene-butadiene transparent impact-resistant resin with silicon hydride groups at the chain initiation end and the chain termination end:

[0093] Under the protection of inert gas, add 2000 g of hexane, 0.1 g of 2,2-bis(2-tetrahydrofuranyl)propane and 0.2 g of 1,1-bis[4-(dimethylsilyl) phenyl] ethylene monomer to the polymerization reactor, add 1.5 ml of alkyl lithium initiator, the initiation temperature is 50 °C, and sequentially add monomers St (100 g), Bd (15 g), Ip (10 g), the reaction temperature is 55 °C. After the monomers react, add 0.1 g of 1,1-bis[4-(dimethylsilyl) phenyl] ethylene monomer to cap the end, and finally add 0.2 g of terminator and N-phenyl-α-naphthylamine (0.05 g) antioxidant, stir evenly and discharge to obtain a linear styrene-butadiene transparent impact-resistant resin with silicon hydride groups at the chain initiation end and the chain termination end, and the number average molecular weight (Mn ) is 53×10 4 g / mol, and the polydispersity index (PDI) ranges from 1.36;

[0094] Step S2, synthesize cholesteric liquid crystal monomers:

[0095] Dissolve p-hydroxybenzoic acid in absolute ethanol, prepare an aqueous solution of potassium hydroxide and potassium iodide and gradually add it dropwise to the p-hydroxybenzoic acid solution, and stir and react at room temperature; then add the halogenated hydrocarbon dropwise to the system, stop heating and refluxing after 10 h. After the reaction is completed, remove the solvent under reduced pressure and wash the crude product with dilute hydrochloric acid multiple times; filter the system under reduced pressure, dry the filter cake, and recrystallize with hot ethanol to obtain a white solid;

[0096] Dissolve the white solid in the acyl chloride, stop heating and refluxing after 6 h. Remove the excess acyl chloride through a vacuum distillation device to obtain a yellow solution. Dissolve cholesterol in a mixed solution of dichloromethane and pyridine, slowly add it dropwise to the above yellow solution, and stop heating and refluxing after 6 h. After the reaction is completed, remove the solvent by rotary evaporation under reduced pressure and obtain a pale yellow powder. Acidify the system overnight and recrystallize with hot ethanol to obtain a cholesteric liquid crystal monomer with a hydroxyl group at the end;

[0097] Step S3, synthesize cholesteric liquid crystal graft-modified styrene-butadiene transparent impact-resistant resin:

[0098] In an anhydrous and anaerobic glove box, add 200 g of linear styrene-butadiene transparent impact-resistant resin functionalized with silicon hydride groups at the chain initiation end and chain termination end and 5 g of cholesteric liquid crystal monomers to the reactor, pour in 10 L of cyclohexane solvent, stir until the solid is completely dissolved, and then add 3 g of cobalt catalyst; seal the system and stir and react for 30 h. After the reaction is completed, obtain a white solid product through post-treatment; the number average molecular weight (M n ) is 106×10 4 g / mol, and the polydispersity index (PDI) ranges from 1.44; the transparency is 78%, the haze is 15%, and the impact strength is 30 kJ / m 2 .

[0099] Example 4:

[0100] Step S1, synthesize star-shaped styrene-butadiene transparent impact-resistant resin (containing Ip) functionalized with silicon hydride groups at the chain ends and in the chain

[0101] Under the protection of inert gas, 1000 g of toluene, 0.1 g of tetrahydrofuran and 0.1 g of 1,1-bis[4-(dimethylsilylhydrido)phenyl]ethylene monomer were added to a polymerization reactor, 1.5 ml of alkyllithium initiator was added, the initiation temperature range was 90 °C, monomers St (50 g), Bd (10 g), Ip (5 g) were added in sequence, and 0.3 g of 1-[4-(triisopropoxysilyl)phenyl]-1-[4-(dimethylsilylhydrido)phenyl]ethylene monomer was added. The reaction temperature was 90 °C. After the monomers reacted completely, 0.5 g of star coupling agent was added; after the coupling reaction was completed, 0.1 g of terminator and N-phenyl-α-naphthylamine (0.05 g) antioxidant were added. After stirring evenly, the product was discharged to obtain a star-shaped styrene-butadiene transparent impact-resistant resin functionalized with silylhydride groups at the chain ends and in the chain, and the number-average molecular weight (M n ) was 150×10 4 g / mol, and the molecular weight distribution index (PDI) ranged from 1.60.

[0102] Step S2, synthesize cholesteric liquid crystal monomers:

[0103] Dissolve p-hydroxybenzoic acid in absolute ethanol, prepare an aqueous solution of potassium hydroxide and potassium iodide and gradually add it dropwise to the p-hydroxybenzoic acid solution, and stir and react at room temperature; then add the halogenated hydrocarbon dropwise to the system, stop heating and refluxing after 12 h. After the reaction is completed, the solvent is removed under reduced pressure and the crude product is washed several times with dilute hydrochloric acid; the system is filtered under reduced pressure, the filter cake is dried, and white solid is obtained after recrystallization with hot ethanol.

[0104] Dissolve the white solid in acyl chloride, stop heating and refluxing after reacting for 24 h. Excess acyl chloride is removed through a vacuum distillation device to obtain a yellow solution. Dissolve cholesterol in a mixed solution of dichloromethane and pyridine, slowly add it dropwise to the above yellow solution, and stop heating and refluxing after reacting for 18 h. After the reaction is completed, the solvent is removed by rotary evaporation under reduced pressure to obtain a pale yellow powder. The system is acidified overnight and then recrystallized with hot ethanol to obtain a cholesteric liquid crystal monomer with a hydroxyl group at the end;

[0105] Step S3, synthesize cholesteric liquid crystal graft-modified styrene-butadiene transparent impact-resistant resin:

[0106] In an anhydrous and anaerobic glove box, 300 g of star-shaped styrene-butadiene transparent impact-resistant resin functionalized with silylhydride groups at the chain ends and in the chain and 10 g of cholesteric liquid crystal monomer were added to a reactor, 15 L of toluene solvent was poured in, and after stirring until the solid was completely dissolved, 5 g of Karstedt's catalyst was added; the system was sealed and stirred for 48 h; after the reaction was completed, a white solid product was obtained through post-treatment, and the number-average molecular weight (M n ) was 300×10 4g / mol, the molecular weight distribution index (PDI) ranges from 1.70, the transparency is 70%, the haze is 20%, and the impact strength is 40 kJ / m 2 .

[0107] The above-described embodiments only represent the implementation modes of the present invention, but should not be construed as limiting the scope of the patent of the present invention. It should be noted that for those skilled in the art, without departing from the concept of the present invention, several modifications and improvements can still be made, and these all belong to the protection scope of the present invention.

Claims

1. A kind of styrene-butadiene transparent impact-resistant resin modified by liquid crystal grafting, characterized in that, The styrene-butadiene transparent impact-resistant resin modified by grafting with liquid crystal is a graft copolymer of a silicone group-functionalized styrene-butadiene transparent impact-resistant resin and a cholesteric liquid crystal monomer. The number-average molecular weight (M n ) of the styrene-butadiene transparent impact-resistant resin modified by grafting with liquid crystal ranges from 2 to 300 × 10 4 g / mol, and the molecular weight distribution index (PDI) ranges from 1.02 to 1.

70. Among them, the mass ratio of the silicone group-functionalized styrene-butadiene transparent impact-resistant resin to the cholesteric liquid crystal monomer is (100 - 500):1; The structural formula of the cholesteric liquid crystal monomer is as follows: Wherein, R represents an alkane chain or an alkane chain with a carbonyl group at the end connected to an oxygen atom, and the number of carbon atoms is 1-18; M represents a vinyl group, an alkynyl group or a hydroxyl group.

2. The styrene-butadiene transparent impact-resistant resin modified by liquid crystal grafting according to claim 1, characterized in that, The number average molecular weight (M n ) of the silicon group-functionalized transparent impact-resistant styrene-butadiene resin ranges from 1 to 150×10 4 g / mol, and the molecular weight distribution index (PDI) ranges from 1.02 to 1.

60.

3. The styrene-butadiene transparent impact-resistant resin modified by liquid crystal grafting according to claim 2, characterized in that, The silicon group-functionalized styrene-butadiene impact-resistant transparent resin is a block copolymer of styrene, butadiene, isoprene, and a silicon group-functionalized 1,1-diphenylethylene derivative; based on the mass of the silicon group-functionalized styrene-butadiene impact-resistant transparent resin being 100%, the styrene content is 45% - 90%, the content of the silicon group-functionalized 1,1-diphenylethylene derivative is 0.2% - 2%, the isoprene content is 0 - 15%, and the rest is butadiene.

4. The styrene-butadiene transparent impact-resistant resin modified by liquid crystal grafting according to claim 3, characterized in that, The silicon group-functionalized 1,1-diphenylethylene derivative is distributed at least at one position of the chain initiation end, the chain terminal, and the chain middle of the silicon group-functionalized styrene-butadiene impact-resistant transparent resin.

5. The styrene-butadiene transparent impact-resistant resin modified by liquid crystal grafting according to claim 3, wherein The silicon group-functionalized 1,1-diphenylethylene derivative is selected from diphenylethylene derivatives containing a silicon hydride group, a siloxane group / silicon hydride group, and a silicon hydride group / amine group; the silicon hydride group, the siloxane group / silicon hydride group, and the silicon hydride group / amine group are connected to the para-position, meta-position, or ortho-position of the phenyl group in the 1,1-diphenylethylene derivative.

6. A preparation method of a liquid crystal graft-modified styrene-butadiene transparent impact-resistant resin as described in any one of claims 1-5, characterized in that, It includes the following steps: S1. In an anhydrous and oxygen-free glove box, add the silicon group-functionalized styrene-butadiene transparent impact-resistant resin, the cholesteric liquid crystal monomer, and the solvent into a reactor, and stir until the solid is completely dissolved; S2. Add a catalyst to the reactor, and under the condition of 20 - 60 °C, seal and stir the reaction for at least 24 h; After the reaction is completed, a white solid product is obtained through post-treatment, which is the liquid crystal graft-modified styrene-butadiene transparent impact-resistant resin.

7. The preparation method according to claim 6, characterized in that, The molar ratio of the silicon group in the silicon group-functionalized styrene-butadiene transparent impact-resistant resin to the cholesteric liquid crystal monomer is 1:1 - 1:

2.

8. The preparation method according to claim 6, wherein The solvent is selected from at least one of benzene, toluene, hexane, and cyclohexane.

9. The preparation method according to claim 8, characterized in that, The addition amount of the solvent is: 5 - 30 ml of the solvent is added per 100 mg of the silicon group-functionalized styrene-butadiene transparent impact-resistant resin.

10. The preparation method according to claim 6, characterized in that, The catalyst is selected from Karstedt's catalyst, iridium complexes, rhodium catalysts, cobalt catalysts, and chiral bisphosphine ligands.

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