Star-shaped grafted modified liquid styrene-butadiene rubber, its preparation method and application

Abstract

This invention relates to the field of rubber preparation, and discloses a star-shaped grafted modified liquid styrene-butadiene rubber (SBR), its preparation method, and its applications. The modified liquid SBR comprises polymeric segments derived from a coupling agent, and multiple butadiene-styrene copolymer segments and cellulose ether-modified terpene resin segments grafted onto the polymeric segments. The coupling agent is selected from polyvinyl aromatic hydrocarbon monomers. The modified liquid SBR achieves polymer bonding at the molecular structural level, exhibiting good compatibility, stability, and adhesion. The resulting modified liquid SBR improves the viscosity, adhesion, and other properties of the copolymer system, and can be used to make high-grade adhesives and coatings, expanding its application range.

Description

Technical Field

[0001] This invention relates to the field of rubber preparation, specifically to a star-shaped grafted modified liquid styrene-butadiene rubber, its preparation method, and its application. Background Technology

[0002] Liquid rubber is generally a polymer with an index-average molecular weight of 2000-15000 g / mol, and its viscosity varies with the relative molecular mass and molecular configuration. Liquid rubber is characterized by its fluidity, wide bulk viscosity range, ease of processing, and suitability for continuous and automated production, thus improving production efficiency and reducing power consumption. Liquid rubber can be directly added with fillers and reinforcing agents to prepare rubber products, or it can be added to thermosetting resins and other polymers for modification. Liquid rubber containing functional groups, due to the presence of active functional groups, is more prone to chain extension and crosslinking into solid vulcanized rubber, which significantly improves physical properties and allows it to react with many other groups to form novel materials with various structures. Liquid rubber is diverse, and according to the presence and location of functional groups, it can be divided into non-functional liquid rubber, atactic functional group liquid rubber, and terminal functional group liquid rubber. Among the many types of liquid rubber, diene-based liquid rubber, especially butadiene-based, was studied as "the rubber of the future" at the end of the 20th century due to its wide availability and low price of raw materials. Liquid nitrile rubber, liquid styrene-butadiene rubber, and liquid isoprene rubber have outstanding application advantages in their respective fields.

[0003] Liquid styrene-butadiene rubber (LSBR) is a low molecular weight copolymer produced by free radical emulsion or anionic polymerization of butadiene and styrene monomers. It has a molecular weight of 2000-15000 g / mol and is a light yellow or light brown transparent viscous liquid. LSBR possesses excellent electrical insulation and physical properties, is insoluble in common organic solvents, and does not melt upon heating. LSBR exhibits good compatibility with certain general-purpose rubbers, allowing for blending and the addition of fillers and oils. Due to the uniform dispersion and good casting flowability of these blended components, it can be injection molded to produce hard rubber products. It can also be used as a plasticizer for styrene-butadiene rubber, nitrile rubber, and neoprene rubber, or as an adhesive, sealant, and in high-grade coatings, thus expanding its application range.

[0004] Domestic and international reports describe the application of liquid rubber in various fields or its modification of various polymers, primarily liquid nitrile rubber and liquid isoprene rubber, or modification of liquid rubber through end-grouping. The adhesion, stability, viscosity, and poor branching of the prepared liquid rubber, as well as improving the viscosity and adhesion of copolymer systems, are problems that need to be solved in this field. Furthermore, there are also problems such as complex processes, difficult practical operation, long reaction cycles, high costs, and the tendency to form gels, causing environmental pollution. Summary of the Invention

[0005] The purpose of this invention is to overcome the problems of poor adhesion, stability, viscosity, bonding performance and branching degree of liquid rubber in the prior art, and to provide a star-shaped grafted modified liquid styrene-butadiene rubber, its preparation method and application.

[0006] The inventors of this invention discovered during their research that modifying liquid styrene-butadiene rubber (SBR) using a common liquid SBR anionic solution polymerization method is simple and reliable. This led to the present invention.

[0007] To achieve the above objectives, a first aspect of the present invention provides a star-shaped grafted modified liquid styrene-butadiene rubber, wherein the modified liquid styrene-butadiene rubber comprises polymeric segments from a coupling agent and a plurality of butadiene-styrene copolymer segments and cellulose ether modified terpene resin segments grafted onto the polymeric segments, wherein the coupling agent is selected from polyvinyl aromatic hydrocarbon monomers.

[0008] A second aspect of the present invention provides a method for preparing star-shaped grafted modified liquid styrene-butadiene rubber, wherein the preparation method includes:

[0009] (1) Butadiene and styrene are copolymerized in the presence of an initiator and a polar activator to obtain an active butadiene-styrene copolymer segment;

[0010] (2) The active butadiene-styrene copolymer segment and the coupling agent are coupled together to obtain an active chain;

[0011] (3) The active chain is polymerized with the modified terpene resin to obtain the star-shaped grafted modified liquid styrene-butadiene rubber.

[0012] A third aspect of the present invention provides a star-shaped grafted modified liquid styrene-butadiene rubber obtained by the preparation method described above.

[0013] The fourth aspect of this invention provides the application of the star-shaped grafted modified liquid styrene-butadiene rubber and the star-shaped grafted modified liquid styrene-butadiene rubber obtained by the preparation method described above in the field of rubber processing.

[0014] Through the above technical solution, the invention provides a modified liquid styrene-butadiene rubber (SBR). From the perspective of polymer chain structure, it is a branched polymer with a star-shaped structure. This means that multiple molecular chains are grafted onto the polymeric chain segments to form different chain segments as branches, similar to connected molecular arms (such as polybutadiene-styrene arms and modified terpene resin polymer arms), referred to as mixed arms. In the modified liquid SBR, the polymeric chain segments formed by polybutadiene-styrene rubber and modified terpene resin through the coupling agent are used as the core and chained together, achieving the combination of different polymer molecular chains at the short-range structural level of the polymer chain, resulting in good compatibility, stability, and adhesion. The obtained modified liquid SBR improves the viscosity, adhesion, and other properties of the copolymer system, and can be used to make high-grade adhesives, plasticizers, and coatings, expanding its application range. Attached Figure Description

[0015] Figure 1 This is a schematic diagram of the molecular chain structure of star-grafted modified liquid styrene-butadiene rubber.

[0016] Explanation of reference numerals in the attached figures

[0017] PSB represents butadiene-styrene copolymer segment, and PT represents cellulose ether modified terpene resin segment. Detailed Implementation

[0018] The endpoints and any values ​​of the ranges disclosed herein are not limited to the precise ranges or values, and these ranges or values ​​should be understood to include values ​​close to these ranges or values. For numerical ranges, the endpoint values ​​of the various ranges, the endpoint values ​​of the various ranges and individual point values, and individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be considered as specifically disclosed herein.

[0019] The first aspect of the present invention provides a star-shaped grafted modified liquid styrene-butadiene rubber, wherein the modified liquid styrene-butadiene rubber comprises polymeric segments from a coupling agent and a plurality of butadiene-styrene copolymeric segments and cellulose ether modified terpene resin segments grafted onto the polymeric segments, wherein the coupling agent is selected from polyvinyl aromatic hydrocarbon monomers.

[0020] In this invention, the modified liquid styrene-butadiene rubber provided is a branched polymer with a star-shaped structure from the perspective of polymer chain structure. The polymer segment formed by the coupling agent serves as the polymer core, and the multiple vinyl functional groups of the coupling agent provide multiple vinyl groups for further grafting of other branches onto the polymer segment. The butadiene-styrene copolymer chain and the cellulose ether modified terpene resin chain can be bonded to the vinyl groups on the polymer segment through their respective carbon-carbon double bonds to form butadiene-styrene copolymer segments and cellulose ether modified terpene resin segments grafted onto the polymer segment. That is, multiple molecular chains are grafted onto the polymer segment to form different segments as branches, similar to connected molecular arms (such as polybutadiene-styrene arms and modified terpene resin polymer arms), which can be called mixed arms. In the modified liquid styrene-butadiene rubber, the polymeric segments formed by the coupling agent of polybutadiene-styrene rubber and modified terpene resin are used as the core to link together, realizing the combination of different polymer molecular chains at the short-range structural level of the polymer chain, which can have good compatibility, stability and adhesion.

[0021] In this invention, the coupling agent is selected from polyvinyl aromatic monomers, which form polymeric segments with multiple molecular arms through self-polymerization, thereby forming polymers with high branching degree.

[0022] In some specific embodiments of the present invention, in the modified liquid styrene-butadiene rubber, based on the sum of the weights of the butadiene-styrene copolymer segments and the cellulose ether-modified terpene resin segments, the content of the cellulose ether-modified terpene resin segments is 20-80 wt%, and the content of the butadiene-styrene copolymer segments is 20-80 wt%. By limiting the above-mentioned contents, the modified liquid styrene-butadiene rubber achieves the bonding of different polymer molecular chains at the short-range structural level of the polymer chain, and can have good compatibility, stability, and adhesion.

[0023] In some embodiments of the present invention, in the modified liquid styrene-butadiene rubber, based on the sum of the weights of the butadiene-styrene copolymer segments and the cellulose ether-modified terpene resin segments, the content of the cellulose ether-modified terpene resin segments can be selected from any value within the range of 20wt%, 30wt%, 40wt%, 50wt%, 60wt%, 70wt%, 80wt%, and any two of the above values. The content of the butadiene-styrene copolymer segments can be selected from any value within the range of 20wt%, 30wt%, 40wt%, 50wt%, 60wt%, 70wt%, 80wt%, and any two of the above values.

[0024] In some specific embodiments of the present invention, the butadiene-styrene copolymer segment contains 50-90 wt% butadiene structural units and 10-50 wt% styrene structural units. By limiting the above contents, the modified liquid styrene-butadiene rubber achieves the bonding of different polymer molecular chains at the short-range structural level of the polymer chain, resulting in good compatibility, stability, and adhesion.

[0025] In some embodiments of the present invention, the content of the butadiene structural unit in the butadiene-styrene copolymer segment can be selected from 50wt%, 60wt%, 70wt%, 80wt%, 90wt%, and any value within the range of any two of the above values. The content of the styrene structural unit can be selected from 10wt%, 20wt%, 30wt%, 40wt%, 50wt%, and any value within the range of any two of the above values.

[0026] In some specific embodiments of the present invention, the cellulose ether-modified terpene resin segment contains 10-40 wt% cellulose ether and 60-90 wt% terpene resin. By limiting the above contents, the modified liquid styrene-butadiene rubber achieves the bonding of different polymer molecular chains at the short-range structural level of the polymer chain, resulting in good compatibility, stability, and adhesion. Specifically, the higher the terpene resin content in the cellulose ether-modified terpene resin segment, the higher the average bonding force of the star-grafted modified liquid styrene-butadiene rubber, and the better the anti-slip properties, high-temperature anti-flow properties, and adhesion of the liquid styrene-butadiene rubber.

[0027] In some embodiments of the present invention, the content of the cellulose ether in the cellulose ether-modified terpene resin segment can be selected from 10 wt%, 20 wt%, 30 wt%, 40 wt%, and any value within the range of any two of the above values. The content of the terpene resin can be selected from 60 wt%, 70 wt%, 80 wt%, 90 wt%, and any value within the range of any two of the above values.

[0028] In some specific embodiments of the present invention, preferably, the coupling agent is selected from divinylbenzene.

[0029] In some specific embodiments of the present invention, the amount of coupling agent used in the modified liquid styrene-butadiene rubber is relatively small. The polymeric segments formed by the coupling agent are used as the core. The core formed by the coupling agent is a macromolecular active species. The macromolecular active species provides the polymer with multiple reactive sites that can further initiate the polymerization of reactive monomers, thereby initiating the polymerization of monomers to form polymeric segments. The proportion of polymeric segments formed by the coupling agent itself is very small relative to the amount of macromolecular polymer, and its content can be excluded from the polymer proportion. The amount of coupling agent used has been described in the text.

[0030] In this invention, functionality refers to the number of active sites on the polymer chain capable of chemically reacting to form new bonds. The more active sites formed, the more polymer segments are formed through monomer polymerization, resulting in better branching of the modified liquid styrene-butadiene rubber and higher functionality. By characterizing and analyzing the polymer segments, the amount of polymer segments formed by the coupling agent can be reflected by the polymer functionality.

[0031] In some specific embodiments of the present invention, the modified liquid styrene-butadiene rubber has a number-average molecular weight of 3000-25000 g / mol, a viscosity of 20-60 Pa·s at 25°C, and a functionality of 4-7. High viscosity indicates good adhesive properties of the liquid styrene-butadiene rubber; high functionality indicates good branching properties of the modified liquid styrene-butadiene rubber.

[0032] A second aspect of the present invention provides a method for preparing star-shaped grafted modified liquid styrene-butadiene rubber, wherein the preparation method includes:

[0033] (1) Butadiene and styrene are copolymerized in the presence of an initiator and a polar activator to obtain an active butadiene-styrene copolymer segment;

[0034] (2) The active butadiene-styrene copolymer segment and the coupling agent are coupled together to obtain an active chain;

[0035] (3) The active chain is polymerized with the modified terpene resin to obtain the star-shaped grafted modified liquid styrene-butadiene rubber.

[0036] In some specific embodiments of the present invention, the method for preparing the modified terpene resin includes: mixing the terpene resin and a solvent, and then adding cellulose ether to obtain the modified terpene resin.

[0037] In some specific embodiments of the present invention, the cellulose ether is selected from one or more of sodium methylcellulose, sodium hydroxypropyl methylcellulose, and sodium carboxymethylcellulose.

[0038] This invention utilizes anionic solution polymerization to prepare the star-shaped grafted modified liquid styrene-butadiene rubber, and the method for modifying liquid styrene-butadiene rubber is simple and reliable.

[0039] In this invention, in step (1), butadiene, styrene monomer, and initiator are added sequentially to the polymerization system. After the polymerization of the first monomer addition is completed, a coupling agent is added to carry out a coupling reaction to obtain the product. In step (3), a modified terpene resin is added, and polymerization is performed to obtain the star-shaped grafted modified liquid styrene-butadiene rubber.

[0040] In some specific embodiments of the present invention, the coupling reaction is that the polymeric segment formed by the coupling agent is bonded to the vinyl group on the polymeric segment through the carbon-carbon double bond contained therein, thereby obtaining the active chain.

[0041] In some specific embodiments of the present invention, the solvent is selected from one or more of pentane, hexane, octane, heptane, cyclohexane, benzene, toluene and ethylbenzene, preferably cyclohexane.

[0042] In some specific embodiments of the present invention, the polar activator is selected from one or more of diethylene glycol dimethyl ether, tetrahydrofuran, diethyl ether, ethyl methyl ether, anisole, diphenyl ether, ethylene glycol dimethyl ether, triethylamine, tetramethylvinyl diamine, and hexamethylphosphonic triamine, preferably selected from one or more of diethylene glycol dimethyl ether, tetrahydrofuran, and tetramethylvinyl diamine. The polymerization system of the present invention requires the addition of a polar organic compound as an activator to induce polarization or solvation effects in the initiator, reduce its degree of association, and increase the initiation reaction rate of initiators such as n-butyllithium. The activator can also adjust the reactivity ratio between butadiene and styrene, enabling random copolymerization. Simultaneously, the polar activator can increase the 1,2-structure content in the butadiene unit.

[0043] In some specific embodiments of the present invention, the initiator is selected from one or more of n-butyllithium, sec-butyllithium, methylbutyllithium, phenylbutyllithium, naphthalenelithium, cyclohexyllithium and dodecyllithium, preferably selected from n-butyllithium and / or sec-butyllithium.

[0044] In some specific embodiments of the present invention, the coupling agent is selected from polyvinyl aromatic hydrocarbons, preferably from divinylbenzene.

[0045] In some specific embodiments of the present invention, the temperature of the copolymerization reaction is 50-90°C, the pressure of the copolymerization reaction is 0.1-0.25 MPa, and the time of the copolymerization reaction is 20-80 min.

[0046] In some specific embodiments of the present invention, the temperature of the coupling reaction is 50-90°C, the pressure of the coupling reaction is 0.1-0.25 MPa, and the time of the coupling reaction is 60-90 min.

[0047] In some specific embodiments of the present invention, the polymerization reaction temperature is 50-90°C, the polymerization reaction pressure is 0.1-0.25 MPa, and the polymerization reaction time is 60-100 min.

[0048] In some specific embodiments of the present invention, after the reaction is complete, the obtained polymer solution is treated with water. The amount of water used is generally 100-300 times the amount of initiator, preferably 150-250 times.

[0049] In some specific embodiments of the present invention, an antioxidant of 0.5%-1% by weight of the polymer can be added to the obtained star-shaped grafted modified liquid styrene-butadiene rubber, and then the rubber is washed, dehydrated and dried to obtain high-performance star-shaped grafted modified liquid styrene-butadiene rubber.

[0050] In some specific embodiments of the present invention, the mixed monomer of butadiene and styrene is 20-80 parts by weight, wherein butadiene accounts for 60-90 wt% of the mixed monomer and styrene accounts for 10-40 wt% of the mixed monomer; preferably, the mixed monomer of butadiene and styrene is 30-70 parts by weight, wherein butadiene accounts for 70-90 wt% of the mixed monomer and styrene accounts for 10-30 wt% of the mixed monomer.

[0051] In some specific embodiments of the present invention, the modified terpene resin is 20-80 parts by weight, wherein the cellulose ether accounts for 10-40 wt% of the modified terpene resin, and the terpene resin accounts for 60-90 wt% of the modified terpene resin; preferably, the modified terpene resin is 30-70 parts by weight, wherein the cellulose ether accounts for 10-30 wt% of the modified terpene resin, and the terpene resin accounts for 70-90 wt% of the modified terpene resin.

[0052] In some specific embodiments of the present invention, the initiator is 0.02-0.2 parts by weight, preferably 0.025-0.1 parts by weight.

[0053] In some specific embodiments of the present invention, the molar ratio of the polar activator to the initiator is 0.1-30:1, preferably 0.1-20:1.

[0054] In some specific embodiments of the present invention, the molar ratio of the coupling agent to the initiator is 0.1-1.5:1, preferably 0.1-1:1.

[0055] In this invention, the functionality is determined by gel permeation chromatography, and the composition and structure of the star-shaped grafted modified liquid styrene-butadiene rubber can be determined by nuclear magnetic resonance, infrared spectroscopy, GPC, elemental analysis, etc., or by preparation and feeding.

[0056] A third aspect of this invention provides a star-shaped grafted modified liquid styrene-butadiene rubber obtained by the preparation method described above. It may have the aforementioned compositional and structural characteristics, which will not be repeated here.

[0057] The fourth aspect of this invention provides the application of the star-shaped grafted modified liquid styrene-butadiene rubber and the star-shaped grafted modified liquid styrene-butadiene rubber obtained by the preparation method described above in the field of rubber processing.

[0058] The present invention will be described in detail below through embodiments.

[0059]

[0060] Molecular weight determination: The molecular weight and distribution of the sample were analyzed using a Viscoteck TDA 302 gel permeation chromatography (GPC) system manufactured by Agilent Technologies, Inc.

[0061] Viscosity determination: The viscosity was determined by rotational viscometer according to the cone-plate viscometer method in accordance with GJB 2050-1994.

[0062] Fourier transform infrared spectroscopy (FTIR) analysis: Analysis was performed using a Nicolet 560 FTIR instrument (USA). No purification was required; potassium bromide pellets were used for coating. This method was used to determine the styrene and butadiene content in the modified liquid styrene-butadiene rubber structure.

[0063] Peel strength test: The average bonding strength was tested using a 5567 universal testing machine from Instron Corporation, USA, in accordance with GB / T7124-2008.

[0064] Unless otherwise specified in the following examples and comparative examples, all conditions were performed under standard conditions or conditions recommended by the manufacturer. Reagents or instruments used, unless otherwise specified, are all commercially available products. The composition and structure of the modified liquid styrene-butadiene rubber described in the following examples and comparative examples can be determined by NMR, IR, GPC, elemental analysis, or by the preparation and feeding process.

[0065] Example 1

[0066] 1) Preparation of modified terpene resin: 4212g of cyclohexane and 374g of terpene resin were added to a reaction vessel, heated to 80℃ and stirred until completely dissolved. Then, 94g of dissolved sodium methyl cellulose was added and stirred to mix evenly to obtain modified terpene resin (wherein, in the obtained cellulose ether modified terpene resin chain segment, the content of terpene resin was 80wt% and the content of cellulose ether was 20wt%).

[0067] 2) In a jacketed 15L stainless steel reactor, the system was purged three times with argon gas. 4212g of cyclohexane, 234g of butadiene, 234g of styrene, and 44.93g of tetrahydrofuran were added to the polymerization reactor, followed by 0.624mol of n-butyllithium. The temperature was raised to 50℃, and polymerization was carried out for 80min. After complete monomer conversion, the temperature was raised to 80℃ (wherein, the butadiene-styrene copolymer segment contained 50wt% butadiene structural units and 50wt% styrene structural units). 0.249mol of divinylbenzene was added to continue coupling. After reacting for 60min, a mixture of 468g of the prepared modified terpene resin and 4212g of cyclohexane was injected into the polymerization reactor, and the reaction continued for another 60min. After the reaction was completed, the coupled reaction mixture was treated with water, and 100g of water and 12g of antioxidant 1010 were added and stirred. The adhesive solution is wet-coagulated and dried to obtain a high-performance star-shaped grafted modified liquid styrene-butadiene rubber (wherein, the content of the cellulose ether modified terpene resin segment in the modified liquid styrene-butadiene rubber is 50 wt%, and the content of the butadiene-styrene copolymer segment is 50 wt%).

[0068] Example 2

[0069] 1) Preparation of modified terpene resin: 4212g of cyclohexane and 374g of terpene resin were added to a reaction vessel, heated to 80℃ and stirred until completely dissolved. Then, 94g of dissolved sodium methyl cellulose was added and stirred to mix evenly to obtain modified terpene resin (wherein, in the obtained cellulose ether modified terpene resin chain segment, the content of terpene resin was 80wt% and the content of cellulose ether was 20wt%).

[0070] 2) In a jacketed 15L stainless steel reactor, the system was purged three times with argon gas. 4212g of cyclohexane, 234g of butadiene, 234g of styrene, and 29.95g of tetrahydrofuran were added to the polymerization reactor, followed by 0.416mol of n-butyllithium. The temperature was raised to 50℃, and polymerization was carried out for 80min. After complete monomer conversion, the temperature was raised to 80℃ (wherein, the butadiene-styrene copolymer segment contained 50wt% butadiene structural units and 50wt% styrene structural units). 0.167mol of divinylbenzene was added to continue coupling. After reacting for 60min, a mixture of 468g of the prepared modified terpene resin and 4212g of cyclohexane was injected into the polymerization reactor, and the reaction continued for another 60min. After the reaction was completed, the coupled reaction mixture was treated with water, and 100g of water and 12g of antioxidant 1010 were added and stirred. The adhesive solution is wet-coagulated and dried to obtain a high-performance star-shaped grafted modified liquid styrene-butadiene rubber (wherein, the content of the cellulose ether modified terpene resin segment in the modified liquid styrene-butadiene rubber is 50 wt%, and the content of the butadiene-styrene copolymer segment is 50 wt%).

[0071] Example 3

[0072] 1) Preparation of modified terpene resin: 4212g of cyclohexane and 327g of terpene resin were added to a reaction vessel, heated to 80℃ and stirred until completely dissolved. Then, 141g of dissolved sodium methyl cellulose was added and stirred to mix evenly to obtain modified terpene resin (wherein, in the obtained cellulose ether modified terpene resin chain segment, the content of terpene resin was 70wt% and the content of cellulose ether was 30wt%).

[0073] 2) In a jacketed 15L stainless steel reactor, the system was purged three times with argon gas. 4212g of cyclohexane, 234g of butadiene, 234g of styrene, and 44.93g of tetrahydrofuran were added to the polymerization reactor, followed by 0.936mol of n-butyllithium. The temperature was raised to 50℃, and polymerization was carried out for 80min. After complete monomer conversion, the temperature was raised to 80℃ (wherein, the butadiene-styrene copolymer segment contained 50wt% butadiene structural units and 50wt% styrene structural units). 0.374mol of divinylbenzene was added to continue coupling. After reacting for 60min, a mixture of 468g of the prepared modified terpene resin and 4212g of cyclohexane was pressed into the polymerization reactor, and the reaction continued for another 60min. After the reaction was completed, the coupled reaction mixture was treated with water, and 100g of water and 12g of antioxidant 1010 were added and stirred. The adhesive solution is wet-coagulated and dried to obtain star-shaped grafted modified liquid styrene-butadiene rubber (wherein, the content of the cellulose ether modified terpene resin segment in the modified liquid styrene-butadiene rubber is 50 wt%, and the content of the butadiene-styrene copolymer segment is 50 wt%).

[0074] Example 4

[0075] 1) Preparation of modified terpene resin: 4212g of cyclohexane and 327g of terpene resin were added to a reaction vessel, heated to 80℃ and stirred until completely dissolved. Then, 141g of dissolved sodium methyl cellulose was added and stirred to mix evenly to obtain modified terpene resin (wherein, in the obtained cellulose ether modified terpene resin chain segment, the content of terpene resin was 70wt% and the content of cellulose ether was 30wt%).

[0076] 2) In a jacketed 15L stainless steel reactor, the system was purged three times with argon gas. 4212g of cyclohexane, 234g of butadiene, 234g of styrene, and 44.93g of tetrahydrofuran were added to the polymerization reactor, followed by 0.624mol of n-butyllithium. The temperature was raised to 50℃, and polymerization was carried out for 80min. After complete monomer conversion, the temperature was raised to 80℃ (wherein, the butadiene-styrene copolymer segment contained 50wt% butadiene structural units and 50wt% styrene structural units). 0.249mol of divinylbenzene was added to continue coupling. After reacting for 60min, a mixture of 468g of the prepared modified terpene resin and 4212g of cyclohexane was pressed into the polymerization reactor, and the reaction continued for another 60min. After the reaction was completed, the coupled reaction mixture was treated with water, and 100g of water and 12g of antioxidant 1010 were added and stirred. The adhesive solution is wet-coagulated and dried to obtain star-shaped grafted modified liquid styrene-butadiene rubber (wherein, the content of the cellulose ether modified terpene resin segment in the modified liquid styrene-butadiene rubber is 50 wt%, and the content of the butadiene-styrene copolymer segment is 50 wt%).

[0077] Example 5

[0078] 1) Preparation of modified terpene resin: 2527g of cyclohexane and 197g of terpene resin were added to a reaction vessel, heated to 80℃ and stirred until completely dissolved. Then 84g of dissolved sodium methyl cellulose was added and stirred to mix evenly to obtain modified terpene resin (wherein, the content of terpene resin in the obtained cellulose ether modified terpene resin chain segment is 70wt% and the content of cellulose ether is 30wt%).

[0079] 2) In a jacketed 15L stainless steel reactor, the system was purged three times with argon gas. 5897g of cyclohexane, 468g of butadiene, 187g of styrene, and 37.73g of tetrahydrofuran were added to the polymerization reactor, followed by 0.524mol of n-butyllithium. The temperature was raised to 50℃, and polymerization was carried out for 80min. After complete monomer conversion, the temperature was raised to 80℃ (wherein, the butadiene-styrene copolymer segment contained 70wt% butadiene structural units and 30wt% styrene structural units). 0.212mol of divinylbenzene was added to continue coupling. After reacting for 60min, a mixture of 281g of the prepared modified terpene resin and 2527g of cyclohexane was injected into the polymerization reactor, and the reaction continued for another 60min. After the reaction was completed, the coupled reaction mixture was treated with water, and 100g of water and 12g of antioxidant 1010 were added and stirred. The adhesive solution is wet-coagulated and dried to obtain star-shaped grafted modified liquid styrene-butadiene rubber (wherein, the content of the cellulose ether modified terpene resin segment in the modified liquid styrene-butadiene rubber is 30 wt%, and the content of the butadiene-styrene copolymer segment is 70 wt%).

[0080] Example 6

[0081] 1) Preparation of modified terpene resin: 2527g of cyclohexane and 225g of terpene resin were added to a reaction vessel, heated to 80℃ and stirred until completely dissolved. Then, 56g of dissolved sodium methyl cellulose was added and stirred to mix evenly to obtain modified terpene resin (wherein, the content of terpene resin in the obtained cellulose ether modified terpene resin chain segment is 80wt% and the content of cellulose ether is 20wt%).

[0082] 2) In a jacketed 15L stainless steel reactor, the system was purged three times with argon gas. 5897g of cyclohexane, 468g of butadiene, 187g of styrene, and 23.58g of tetrahydrofuran were added to the polymerization reactor, followed by 0.327mol of n-butyllithium. The temperature was raised to 50℃, and polymerization was carried out for 80min. After complete monomer conversion, the temperature was raised to 80℃ (wherein, the butadiene-styrene copolymer segment contained 70wt% butadiene structural units and 30wt% styrene structural units). 0.131mol of divinylbenzene was added to continue coupling. After reacting for 60min, a mixture of 281g of the prepared modified terpene resin and 2527g of cyclohexane was pressed into the polymerization reactor, and the reaction was continued for another 60min. After the reaction was completed, the coupled reaction mixture was treated with water, and 100g of water and 12g of antioxidant 1010 were added and stirred. The adhesive solution is wet-coagulated and dried to obtain star-shaped grafted modified liquid styrene-butadiene rubber (wherein, the content of the cellulose ether modified terpene resin segment in the modified liquid styrene-butadiene rubber is 30 wt%, and the content of the butadiene-styrene copolymer segment is 70 wt%).

[0083] Example 7

[0084] 1) Preparation of modified terpene resin: In a reaction vessel, 2527g of cyclohexane and 225g of terpene resin (accounting for 80wt% of the modified terpene resin chain segment) were added. After heating to 80℃, the mixture was stirred until completely dissolved. Then, 56g of dissolved sodium methyl cellulose (accounting for 20wt% of the modified terpene resin chain segment) was added and stirred until homogeneous to obtain modified terpene resin (wherein, in the obtained cellulose ether modified terpene resin chain segment, the content of terpene resin is 80wt% and the content of cellulose ether is 20wt%).

[0085] 2) In a jacketed 15L stainless steel reactor, the system was purged three times with argon gas. 5897g of cyclohexane, 557g of butadiene, 98g of styrene, and 37.73g of tetrahydrofuran were added to the polymerization reactor, followed by 0.524mol of n-butyllithium. The temperature was raised to 50℃, and polymerization was carried out for 80min. After complete monomer conversion, the temperature was raised to 80℃ (wherein, the butadiene-styrene copolymer segment contained 85wt% butadiene structural units and 15wt% styrene structural units). 0.212mol of divinylbenzene was added to continue coupling. After reacting for 60min, a mixture of 281g of the prepared modified terpene resin (30wt% of the total) and 2527g of cyclohexane was injected into the polymerization reactor, and the reaction was continued for another 60min. After the reaction was completed, the coupled reaction mixture was treated with water, and 100g of water and 12g of antioxidant 1010 were added and stirred. The adhesive solution is wet-coagulated and dried to obtain star-shaped grafted modified liquid styrene-butadiene rubber (wherein, the content of the cellulose ether modified terpene resin segment in the modified liquid styrene-butadiene rubber is 30 wt%, and the content of the butadiene-styrene copolymer segment is 70 wt%).

[0086] Example 8

[0087] 1) Preparation of modified terpene resin: 2527g of cyclohexane and 197g of terpene resin were added to a reaction vessel, heated to 80℃ and stirred until completely dissolved. Then 84g of dissolved sodium methyl cellulose was added and stirred to mix evenly to obtain modified terpene resin (wherein, the content of terpene resin in the obtained cellulose ether modified terpene resin chain segment is 70wt% and the content of cellulose ether is 30wt%).

[0088] 2) In a jacketed 15L stainless steel reactor, the system was purged three times with argon gas. 5897g of cyclohexane, 557g of butadiene, 98g of styrene, and 53.90g of tetrahydrofuran were added to the polymerization reactor, followed by 0.504mol of n-butyllithium. The temperature was raised to 50℃, and polymerization was carried out for 80min. After complete monomer conversion, the temperature was raised to 80℃ (wherein, the butadiene-styrene copolymer segment contained 85wt% butadiene structural units and 15wt% styrene structural units). 0.301mol of divinylbenzene was added to continue coupling. After reacting for 60min, a mixture of 281g of the prepared modified terpene resin and 2527g of cyclohexane was pressed into the polymerization reactor, and the reaction was continued for another 60min. After the reaction was completed, the coupled reaction mixture was treated with water, and 100g of water and 12g of antioxidant 1010 were added and stirred. The adhesive solution is wet-coagulated and dried to obtain star-shaped grafted modified liquid styrene-butadiene rubber (wherein, the content of the cellulose ether modified terpene resin segment in the modified liquid styrene-butadiene rubber is 30 wt%, and the content of the butadiene-styrene copolymer segment is 70 wt%).

[0089] Example 9

[0090] 1) Preparation of modified terpene resin: In a reaction vessel, 2611g of cyclohexane and 211g of terpene resin were added, heated to 80℃ and stirred until completely dissolved. Then, 70g of dissolved sodium methyl cellulose was added and stirred to mix evenly to obtain modified terpene resin (wherein, in the obtained cellulose ether modified terpene resin chain segment, the content of terpene resin was 75wt% and the content of cellulose ether was 25wt%).

[0091] 2) In a jacketed 15L stainless steel reactor, the system was purged three times with argon gas. 5813g of cyclohexane, 478g of butadiene, 84g of styrene, and 37.73g of tetrahydrofuran were added to the polymerization reactor, followed by 0.281mol of n-butyllithium. The temperature was raised to 50℃, and polymerization was carried out for 80min. After complete monomer conversion, the temperature was raised to 80℃ (wherein, the butadiene-styrene copolymer segment contained 85wt% butadiene structural units and 15wt% styrene structural units). 0.212mol of divinylbenzene was added to continue coupling. After reacting for 60min, a mixture of 281g of the prepared modified terpene resin and 2527g of cyclohexane was injected into the polymerization reactor, and the reaction continued for another 60min. After the reaction was completed, the coupled reaction mixture was treated with water, and 100g of water and 12g of antioxidant 1010 were added and stirred. The adhesive solution is wet-coagulated and dried to obtain star-shaped grafted modified liquid styrene-butadiene rubber (wherein, the content of the cellulose ether modified terpene resin segment in the modified liquid styrene-butadiene rubber is 30 wt%, and the content of the butadiene-styrene copolymer segment is 70 wt%).

[0092] Example 10

[0093] 1) Preparation of modified terpene resin: 2527g of cyclohexane and 225g of terpene resin were added to a reaction vessel, heated to 80℃ and stirred until completely dissolved. Then, 56g of dissolved sodium methyl cellulose was added and stirred to mix evenly to obtain modified terpene resin (wherein, the content of terpene resin in the obtained cellulose ether modified terpene resin chain segment is 80wt% and the content of cellulose ether is 20wt%).

[0094] 2) In a jacketed 15L stainless steel reactor, the system was purged three times with argon gas. 5897g of cyclohexane, 468g of butadiene, 187g of styrene, and 23.58g of tetrahydrofuran were added to the polymerization reactor, followed by 0.197mol of n-butyllithium. The temperature was raised to 50℃, and polymerization was carried out for 80min. After complete monomer conversion, the temperature was raised to 80℃ (wherein, the butadiene-styrene copolymer segment contained 70wt% butadiene structural units and 30wt% styrene structural units). 0.197mol of divinylbenzene was added to continue coupling. After reacting for 60min, a mixture of 281g of the prepared modified terpene resin and 2527g of cyclohexane was injected into the polymerization reactor, and the reaction was continued for another 60min. After the reaction was completed, the coupled reaction mixture was treated with water, and 100g of water and 12g of antioxidant 1010 were added and stirred. The adhesive solution is wet-coagulated and dried to obtain star-shaped grafted modified liquid styrene-butadiene rubber (wherein, the content of the cellulose ether modified terpene resin segment in the modified liquid styrene-butadiene rubber is 30 wt%, and the content of the butadiene-styrene copolymer segment is 70 wt%).

[0095] Example 11

[0096] 1) Preparation of modified terpene resin: 2527g of cyclohexane and 225g of terpene resin were added to a reaction vessel, heated to 80℃ and stirred until completely dissolved. Then, 56g of dissolved sodium methyl cellulose was added and stirred to mix evenly to obtain modified terpene resin (wherein, the content of terpene resin in the obtained cellulose ether modified terpene resin chain segment is 80wt% and the content of cellulose ether is 20wt%).

[0097] 2) In a jacketed 15L stainless steel reactor, the system was purged three times with argon gas. 5897g of cyclohexane, 468g of butadiene, 187g of styrene, and 23.58g of tetrahydrofuran were added to the polymerization reactor, followed by 0.143mol of n-butyllithium. The temperature was raised to 50℃, and polymerization was carried out for 80min. After complete monomer conversion, the temperature was raised to 80℃ (wherein, the butadiene-styrene copolymer segment contained 70wt% butadiene structural units and 30wt% styrene structural units). 0.172mol of divinylbenzene was added to continue coupling. After reacting for 60min, a mixture of 281g of the prepared modified terpene resin and 2527g of cyclohexane was pressed into the polymerization reactor, and the reaction was continued for another 60min. After the reaction was completed, the coupled reaction mixture was treated with water, and 100g of water and 12g of antioxidant 1010 were added and stirred. The adhesive solution is wet-coagulated and dried to obtain star-shaped grafted modified liquid styrene-butadiene rubber (wherein, the content of the cellulose ether modified terpene resin segment in the modified liquid styrene-butadiene rubber is 30 wt%, and the content of the butadiene-styrene copolymer segment is 70 wt%).

[0098] Comparative Example 1

[0099] The method is the same as in Example 1, except that the terpene resin is not modified; that is, the styrene-butadiene rubber segment and the terpene resin are directly coupled and then condensed.

[0100] The specific preparation steps are as follows: In a 15L stainless steel reactor with a jacket, the system is purged three times with argon gas. Add 4212g of cyclohexane, 234g of butadiene (50wt% of the mixed monomers), 234g of styrene (50wt% of the mixed monomers), and 44.93g of tetrahydrofuran to the polymerization reactor, followed by 0.624mol of n-butyllithium. Heat to 50℃ and polymerize for 80min. After complete monomer conversion, heat to 80℃ and add 0.249mol of divinylbenzene to continue coupling. After reacting for 60min, press a mixture of 468g of terpene resin (50wt% of the total) and 4212g of cyclohexane into the polymerization reactor and continue reacting for another 60min. After the reaction is complete, treat the coupled reaction mixture with water, add 100g of water and 12g of antioxidant 1010, and stir. The resulting liquid styrene-butadiene rubber is obtained by wet coagulation and drying.

[0101] Comparative Example 2

[0102] The method is the same as in Example 2, except that the terpene resin is not modified; that is, the styrene-butadiene rubber segment and the terpene resin are directly coupled and then aggregated.

[0103] The specific preparation steps are as follows: In a 15L stainless steel reactor with a jacket, the system is purged three times with argon gas. Add 4212g of cyclohexane, 234g of butadiene (50wt% of the mixed monomers), 234g of styrene (50wt% of the mixed monomers), and 29.95g of tetrahydrofuran to the polymerization reactor, then add 0.416mol of n-butyllithium. Heat to 50℃ and polymerize for 80min. After complete monomer conversion, heat to 80℃ and add 0.167mol of divinylbenzene to continue coupling. After reacting for 60min, press a mixture of 468g of terpene resin (50wt% of the total) and 4212g of cyclohexane into the polymerization reactor and continue reacting for 60min. After the reaction is complete, treat the coupled reaction mixture with water, add 100g of water and 12g of antioxidant 1010, and stir. The resulting liquid styrene-butadiene rubber is obtained by wet coagulation and drying.

[0104] Comparative Example 3

[0105] The method is the same as in Example 3, except that the terpene resin is not modified; that is, the styrene-butadiene rubber segment and the terpene resin are directly coupled and then aggregated.

[0106] The specific preparation steps are as follows: In a 15L stainless steel reactor with a jacket, the system is purged three times with argon gas. Add 4212g of cyclohexane, 234g of butadiene (50wt% of the mixed monomers), 234g of styrene (50wt% of the mixed monomers), and 44.93g of tetrahydrofuran to the polymerization reactor, followed by 0.936mol of n-butyllithium. Heat to 50℃ and polymerize for 80min. After complete monomer conversion, heat to 80℃ and add 0.374mol of divinylbenzene to continue coupling. After reacting for 60min, press a mixture of 468g of terpene resin (50wt% of the total) and 4212g of cyclohexane into the polymerization reactor and continue reacting for another 60min. After the reaction is complete, treat the coupled reaction mixture with water, add 100g of water and 12g of antioxidant 1010, and stir. The resulting liquid styrene-butadiene rubber is obtained by wet coagulation and drying.

[0107] Comparative Example 4

[0108] The method is the same as in Example 4, except that the terpene resin is not modified; that is, the styrene-butadiene rubber segment and the terpene resin are directly coupled and then condensed.

[0109] The specific preparation steps are as follows: In a 15L stainless steel reactor with a jacket, the system is purged three times with argon gas. Add 4212g of cyclohexane, 234g of butadiene (50wt% of the mixed monomers), 234g of styrene (50wt% of the mixed monomers), and 44.93g of tetrahydrofuran to the polymerization reactor, followed by 0.624mol of n-butyllithium. Heat to 50℃ and polymerize for 80min. After complete monomer conversion, heat to 80℃ and add 0.249mol of divinylbenzene to continue coupling. After reacting for 60min, press a mixture of 468g of terpene resin (50wt% of the total) and 4212g of cyclohexane into the polymerization reactor and continue reacting for another 60min. After the reaction is complete, treat the coupled reaction mixture with water, add 100g of water and 12g of antioxidant 1010, and stir. The resulting liquid styrene-butadiene rubber is obtained by wet coagulation and drying.

[0110] Comparative Example 5

[0111] The method of Example 5 is the same, except that no coupling agent is added for the coupling reaction. That is, after the polymerization reaction of butadiene and styrene is completed, the modified terpene resin is added and mixed.

[0112] The specific preparation steps are as follows: 1) Preparation of modified terpene resin: In a reactor, add 2527g of cyclohexane and 187g of terpene resin (accounting for 70wt% of the modified terpene resin chain segments), heat to 80℃ and stir until completely dissolved, then add 94g of dissolved sodium methyl cellulose (accounting for 30wt% of the modified terpene resin chain segments), stir and mix evenly to obtain modified terpene resin. 2) In a 15L stainless steel reactor with a jacket, purge the system three times with argon gas. 5897g of cyclohexane, 468g of butadiene (70wt% of the mixed monomers), 187g of styrene (30wt% of the mixed monomers), and 37.73g of tetrahydrofuran were added to a polymerization reactor, followed by 0.281mol of n-butyllithium. The temperature was raised to 50℃, and polymerization was carried out for 80 min. After complete monomer conversion, the temperature was raised to 80℃, and the reaction was carried out for 60 min. Then, a mixture of 281g of the prepared modified terpene resin (30wt% of the total) and 2527g of cyclohexane was pressed into the polymerization reactor and mixed for 20 min. After mixing, 100g of water and 12g of antioxidant 1010 were added, and the mixture was stirred. The resulting solution was wet-coagulated and dried to obtain liquid styrene-butadiene rubber.

[0113] Comparative Example 6

[0114] The method of Example 6 is the same, except that no coupling agent is added for the coupling reaction. That is, after the polymerization reaction of butadiene and styrene is completed, the modified terpene resin is added and mixed.

[0115] The specific preparation steps are as follows: 1) Preparation of modified terpene resin: In a reactor, add 2527g of cyclohexane and 234g of terpene resin (accounting for 80wt% of the modified terpene resin chain segments), heat to 80℃ and stir until completely dissolved, then add 47g of dissolved sodium methyl cellulose (accounting for 20wt% of the modified terpene resin chain segments), stir and mix evenly to obtain modified terpene resin. 2) In a 15L stainless steel reactor with a jacket, purge the system three times with argon gas. 5897g of cyclohexane, 468g of butadiene (70wt% of the mixed monomers), 187g of styrene (30wt% of the mixed monomers), and 23.58g of tetrahydrofuran were added to a polymerization reactor, followed by 0.327mol of n-butyllithium. The temperature was raised to 50℃, and polymerization was carried out for 80 min. After complete monomer conversion, the temperature was raised to 80℃, and the reaction was carried out for 60 min. Then, a mixture of 281g of the prepared modified terpene resin (30wt% of the total) and 2527g of cyclohexane was pressed into the polymerization reactor and mixed for 20 min. After mixing, 100g of water and 12g of antioxidant 1010 were added, and the mixture was stirred. The resulting liquid styrene-butadiene rubber was obtained by wet coagulation and drying.

[0116] Comparative Example 7

[0117] The method of Example 7 is the same, except that the terpene resin is not modified. Instead, the styrene-butadiene rubber segment and the terpene resin are directly coupled, dissolved sodium carboxymethyl cellulose is added, and then coagulation is carried out.

[0118] The specific preparation steps are as follows: In a 15L stainless steel reactor with a jacket, argon gas is passed through the system to replace it three times. Add 5897g of cyclohexane, 557g of butadiene (85wt% of the total monomers), 98g of styrene (15wt% of the total monomers), and 37.73g of tetrahydrofuran to a polymerization reactor. Then add 0.524mol of n-butyllithium. Heat to 50℃ and polymerize for 80min. After complete monomer conversion, heat to 80℃ and add 0.212mol of divinylbenzene to continue coupling. React for 60min. Then add a mixture of 225g of terpene resin (21wt% of the total) and 1685g of cyclohexane into the polymerization reactor and continue reacting for 60min. Then add a mixture of 56g of dissolved sodium carboxymethyl cellulose (9wt% of the total) and 842g of cyclohexane. Mix for 20min. Treat the coupled reaction mixture with water, add 100g of water and 12g of antioxidant 1010, and stir. The solution is wet-coagulated and dried to obtain liquid styrene-butadiene rubber.

[0119] Comparative Example 8

[0120] The method of Example 8 is the same, except that the terpene resin is not modified. Instead, the styrene-butadiene rubber segment and the terpene resin are directly coupled, dissolved sodium carboxymethyl cellulose is added, and then coagulation is carried out.

[0121] The specific preparation steps are as follows: In a 15L stainless steel reactor with a jacket, argon gas is passed through the system to replace it three times. Add 5897g of cyclohexane, 557g of butadiene (85wt% of the mixed monomers), 98g of styrene (15wt% of the mixed monomers), and 53.90g of tetrahydrofuran to a polymerization reactor, followed by 0.504mol of n-butyllithium. Heat to 50℃ and polymerize for 80min. After complete monomer conversion, heat to 80℃ and add 0.301mol of divinylbenzene to continue coupling. React for 60min, then add a mixture of 197g of terpene resin (21wt% of the total) and 1685g of cyclohexane into the polymerization reactor and continue reacting for 60min. Next, add a mixture of 84g of dissolved sodium carboxymethyl cellulose (9wt% of the total) and 842g of cyclohexane, mix for 20min, and then treat the coupled reaction mixture with water. Add 100g of water and 12g of antioxidant 1010, and stir. The resulting liquid styrene-butadiene rubber is obtained by wet coagulation and drying.

[0122] Comparative Example 9

[0123] The method is the same as in Example 10, except that the terpene resin is not modified. Instead, the styrene-butadiene rubber segment and the terpene resin are directly coupled, dissolved sodium carboxymethyl cellulose is added, and then coagulation is carried out.

[0124] The specific preparation steps are as follows: In a 15L stainless steel reactor with a jacket, argon gas is passed through the system to replace it three times. 5897 g of cyclohexane, 468 g of butadiene (70 wt% of the mixed monomers), 187 g of styrene (30 wt% of the mixed monomers), and 23.58 g of tetrahydrofuran were added to a polymerization reactor. Then, 0.262 mol of n-butyllithium was added. The temperature was raised to 50 °C, and polymerization was carried out for 80 min. After complete monomer conversion, the temperature was raised to 80 °C, and 0.131 mol of divinylbenzene was added to continue coupling. After reacting for 60 min, a mixture of 225 g of terpene resin (24 wt% of the total) and 2527 g of cyclohexane was added to the polymerization reactor and reacted for another 60 min. Then, a mixture of 56 g of dissolved sodium carboxymethyl cellulose (6 wt% of the total) and 842 g of cyclohexane was added and mixed for 20 min. The coupled reaction mixture was treated with water, and 100 g of water and 12 g of antioxidant 1010 were added and stirred. The solution was wet-coagulated and dried to obtain liquid styrene-butadiene rubber.

[0125] The relevant performance was measured for the results of Examples 1-11 and Comparative Examples 1-9, and the results are shown in Table 1. The styrene content is based on the total modified liquid styrene-butadiene rubber.

[0126] Table 1

[0127]

[0128]

[0129] As can be seen from the results in Table 1, the star-shaped grafted modified liquid styrene-butadiene rubber of the present invention is synthesized by a two-stage feeding method (feeding of butadiene-styrene copolymer monomer segments and feeding of cellulose ether modified terpene resin segments). The star-shaped grafted modified liquid styrene-butadiene rubber with mixed arms (such as polybutadiene-styrene arms and modified terpene resin polymer arms) is synthesized by the presence of mixed arms. Due to the presence of mixed arms, it is equivalent to linking polybutadiene-styrene rubber and modified terpene resin together through the polymer segment core formed by the coupling agent. This achieves the combination of different polymer molecular chains at the short-range structural level of the polymer chain, which can promote the synergistic optimization of various properties of the product and enable the modified rubber to have good compatibility, stability and adhesion.

[0130] Average bond strength refers to the average peel strength between the adhesive and the substrate in a peel test, usually expressed as stress per unit area. It can be used to compare the adhesive properties of liquid styrene-butadiene rubber in the examples and comparative examples under different conditions. A comparison between Examples 1-10 and Comparative Examples 1-9 shows that as the molecular weight and viscosity of the grafted modified rubber increase, the average bond strength of the grafted modified rubber increases. Furthermore, the higher the functionality and branching degree of the grafted modified rubber, the greater its average bond strength.

[0131] As can be seen from Examples 1-11, with the increase of polymer molecular weight, the polymer viscosity gradually increases, and the average bonding force of the modified rubber also gradually increases. Similarly, with the increase of polymer functionality, the average bonding force of the modified rubber also gradually increases, resulting in better adhesion performance of the grafted modified rubber. A comparison between the examples and the corresponding comparative examples shows that the average bonding force of the examples is higher than that of the comparative examples, indicating that the adhesion performance of the comparative examples is not as good as that of the liquid styrene-butadiene rubber sample in the examples. The liquid styrene-butadiene rubber in the examples also has higher functionality. Higher functionality leads to greater branching and viscosity in the liquid styrene-butadiene rubber. Higher viscosity results in better adhesion performance of the liquid styrene-butadiene rubber.

[0132] A comparison of Examples 1-4 and Comparative Examples 1-4 shows that after modification of the terpene resin, the viscosity and average bonding force of the grafted modified rubber both increase, indicating that the adhesion performance of the modified liquid styrene-butadiene rubber in the examples is better than that in the comparative examples, demonstrating that the modified cellulose ether achieves a good adhesive effect. The cellulose ether-modified terpene resin segments affect the average bonding force of the prepared rubber, and the rubber with the structure of the present invention exhibits better adhesion.

[0133] A comparison of Examples 5-6 and Comparative Examples 5-6 shows that when a coupling agent is added to couple the modified terpene resin, the modified liquid styrene-butadiene rubber forms a mixed arm. Therefore, the viscosity, functionality, and average binding force of the star-shaped modified liquid styrene-butadiene rubber in Examples 5-6 are greater than those in Comparative Examples 5-6, indicating that the adhesion performance of the star-shaped modified liquid styrene-butadiene rubber in Examples 5-6 is better than that in Comparative Examples 5-6. Thus, the coupling effect of the divinylbenzene coupling agent can chain polybutadiene-styrene rubber and modified terpene resin together, promoting the synergistic optimization of various product properties and enabling the modified rubber to possess good compatibility, stability, and adhesion.

[0134] As can be seen from the results in Table 1, comparing Example 1 and Example 3, and comparing Example 2 and Example 4, under the same styrene and butadiene content, the terpene resin content in the cellulose ether modified terpene resin chain increases, resulting in a larger average bonding force and better adhesiveness of the prepared modified rubber.

[0135] Examples 1-11 of the star-shaped grafted modified liquid styrene-butadiene rubber of the present invention exhibit higher viscosity, higher branching degree, and significantly better adhesion and compatibility. The greater the adhesion and bonding force, the higher the viscosity, and the better the adhesion of the liquid styrene-butadiene rubber. This indicates that the modified liquid styrene-butadiene rubber possesses advantages such as good anti-slip properties, high-temperature anti-flow properties, and good adhesion and bonding force, thus broadening its application range.

[0136] The preferred embodiments of the present invention have been described in detail above; however, the present invention is not limited thereto. Within the scope of the inventive concept, various simple modifications can be made to the technical solutions of the present invention, including combinations of various technical features in any other suitable manner. These simple modifications and combinations should also be considered as the content disclosed in the present invention and are all within the protection scope of the present invention.

Claims

1. A star-shaped grafted modified liquid styrene-butadiene rubber, characterized in that, The modified liquid styrene-butadiene rubber comprises polymeric segments from a coupling agent and multiple butadiene-styrene copolymer segments and cellulose ether modified terpene resin segments grafted onto the polymeric segments, wherein the coupling agent is selected from polyvinyl aromatic monomers. In the modified liquid styrene-butadiene rubber, based on the sum of the weights of the butadiene-styrene copolymer segments and the cellulose ether-modified terpene resin segments, the content of the cellulose ether-modified terpene resin segments is 20-30 wt%, and the content of the butadiene-styrene copolymer segments is 70-80 wt%. In the butadiene-styrene copolymer segment, the content of butadiene structural units is 70-85 wt%, and the content of styrene structural units is 15-30 wt%. In the cellulose ether-modified terpene resin segment, the content of the cellulose ether is 20-30 wt%, and the content of the terpene resin is 70-80 wt%. The modified liquid styrene-butadiene rubber has a number-average molecular weight of 3000-25000 g / mol, a viscosity of 20-60 Pa·S at 25℃, and a functionality of 4-7.

2. The modified liquid styrene-butadiene rubber according to claim 1, characterized in that, The coupling agent is selected from divinylbenzene.

3. A method for preparing star-shaped grafted modified liquid styrene-butadiene rubber, characterized in that, The preparation method includes: (1) Butadiene and styrene are copolymerized in the presence of an initiator and a polar activator to obtain an active butadiene-styrene copolymer segment; (2) The active butadiene-styrene copolymer segment and the coupling agent are coupled together to obtain an active chain; the coupling agent is selected from polyvinyl aromatic monomers; (3) The active chain is polymerized with the modified terpene resin to obtain the star-shaped grafted modified liquid styrene-butadiene rubber; In step (1), the mixed monomers of butadiene and styrene are 70-80 parts by weight, wherein butadiene accounts for 70-85 wt% of the mixed monomers and styrene accounts for 15-30 wt% of the mixed monomers. In step (3), the modified terpene resin is 20-30 parts by weight, and the modified terpene resin is a cellulose ether modified terpene resin, wherein the cellulose ether accounts for 20-30 wt% of the amount of the modified terpene resin, and the terpene resin accounts for 70-80 wt% of the amount of the modified terpene resin.

4. The preparation method according to claim 3, characterized in that, The method for preparing the modified terpene resin includes: mixing the terpene resin and a solvent, and then adding cellulose ether to obtain the modified terpene resin.

5. The preparation method according to claim 4, characterized in that, The solvent is selected from one or more of pentane, hexane, octane, heptane, cyclohexane, benzene, toluene, and ethylbenzene.

6. The preparation method according to claim 5, characterized in that, The solvent is cyclohexane.

7. The preparation method according to claim 4, characterized in that, The polar activator is selected from one or more of diethylene glycol dimethyl ether, tetrahydrofuran, diethyl ether, ethyl methyl ether, anisole, diphenyl ether, ethylene glycol dimethyl ether, triethylamine, tetramethylvinyl diamine, and hexamethylphosphonic triamine.

8. The preparation method according to claim 7, characterized in that, The polar activator is selected from one or more of diethylene glycol dimethyl ether, tetrahydrofuran, and tetramethylvinyldiamine.

9. The preparation method according to claim 3, characterized in that, The initiator is selected from one or more of n-butyllithium, sec-butyllithium, methylbutyllithium, phenylbutyllithium, naphthalenelithium, cyclohexyllithium, and dodecyllithium.

10. The preparation method according to claim 9, characterized in that, The initiator is selected from n-butyllithium and / or sec-butyllithium.

11. The preparation method according to claim 3, characterized in that, The coupling agent is selected from divinylbenzene.

12. The preparation method according to claim 3, characterized in that, The copolymerization reaction is carried out at a temperature of 50-90℃, a pressure of 0.1-0.25MPa, and a time of 20-80min.

13. The preparation method according to claim 3, characterized in that, The coupling reaction is carried out at a temperature of 50-90℃, a pressure of 0.1-0.25MPa, and a time of 60-90min.

14. The preparation method according to claim 3, characterized in that, The polymerization reaction is carried out at a temperature of 50-90℃, a pressure of 0.1-0.25MPa, and a time of 60-100min.

15. The preparation method according to claim 3, characterized in that, The initiator is 0.02-0.2 parts by weight.

16. The preparation method according to claim 15, characterized in that, The initiator is 0.025-0.1 parts by weight.

17. The preparation method according to claim 3, characterized in that, The molar ratio of the polar activator to the initiator is 0.1-30:

1.

18. The preparation method according to claim 17, characterized in that, The molar ratio of the polar activator to the initiator is 0.1-20:

1.

19. The preparation method according to claim 3, characterized in that, The molar ratio of the coupling agent to the initiator is 0.1-1.5:

1.

20. The preparation method according to claim 19, characterized in that, The molar ratio of the coupling agent to the initiator is 0.1-1:

1.

21. Star-shaped grafted modified liquid styrene-butadiene rubber obtained by the preparation method according to any one of claims 3-20.

22. The application of the star-shaped grafted modified liquid styrene-butadiene rubber according to any one of claims 1-2 or the star-shaped grafted modified liquid styrene-butadiene rubber obtained by the preparation method according to any one of claims 3-20 in the field of rubber processing.

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