Butadiene-styrene block copolymer mixture and its preparation method and application

Abstract

The present invention relates to the technical field of polymer material synthesis and preparation, and discloses a styrene butadiene block polymer mixture and its preparation method and application. The mixture comprises a linear styrene butadiene block copolymer and a linear styrene-butadiene-styrene block copolymer; the weight ratio of the structural unit A from butadiene to the structural unit B from styrene in the mixture is 3-4:1; the weight ratio of the styrene block to the styrene non-block in the mixture is 2.3-3.6:1; the number average molecular weight is 130,000-170,000, and the molecular weight distribution is 1-1.2. The styrene butadiene block polymer mixture comprises a linear styrene butadiene block copolymer of a specific structure and a linear styrene-butadiene-styrene block copolymer of a specific structure, and the mixture has a specific structure, so that the mixture has excellent high and low temperature performance, excellent initial adhesion performance and mechanical properties, and can be applied to self-adhesive waterproof membranes.

Description

Technical Field

[0001] The present invention relates to the technical field of polymer material synthesis and preparation, and in particular to a styrene-butadiene block polymer mixture, a preparation method and an application thereof. Background Art

[0002] With the continuous introduction of new regulations and standards for the waterproofing industry, downstream companies are placing increasingly stringent requirements on the comprehensive performance of segmented styrene-butadiene rubber (SBBR) used in waterproofing membranes. High-performance modified polymers for waterproofing membranes place higher demands on initial adhesion, heat resistance, aging resistance, and mechanical strength.

[0003] For self-adhesive waterproofing membranes, styrene-butadiene-styrene block polymers are used to improve the softening point, ductility, mechanical strength, and low-temperature flexibility of the modified asphalt. SSBSP itself is not self-adhesive and requires the presence of a softening oil to develop adhesive properties. Traditional sSBSPs used in waterproofing membranes exhibit a two-phase separation structure, resulting in strong cohesion, poor low-temperature flexibility, and a brittle temperature generally above -5°C.

[0004] Solution-polymerized styrene-butadiene rubber (SBR) has good initial adhesion, but due to the completely random distribution of butadiene and styrene in the molecular chain, its strength is relatively poor and cannot meet the mechanical strength requirements of waterproof membranes. Linear styrene-butadiene block copolymers (LSBCCs) combine the functions of styrene-butadiene-styrene block polymers and solution-polymerized styrene-butadiene rubber, resulting in waterproof membranes with more balanced high and low temperature performance. However, their peel strength and needle penetration indicators cannot meet the requirements of high-performance self-adhesive waterproof membranes. Summary of the Invention

[0005] The purpose of the present invention is to overcome the problem in the prior art that the mechanical properties, hardness, initial adhesion and ductility of styrene-butadiene block polymers for waterproof membranes cannot be simultaneously met, and to provide a styrene-butadiene block polymer mixture and its preparation method and application. The styrene-butadiene block polymer mixture contains a linear styrene-butadiene block copolymer with a specific structure and a linear styrene-butadiene-styrene block copolymer with a special structure. At the same time, the mixture has a specific structure, so that the styrene-butadiene block polymer mixture has excellent high and low temperature performance, excellent initial adhesion and mechanical properties, and can be suitable for self-adhesive waterproof membranes.

[0006] In order to achieve the above object, the first aspect of the present invention provides a butadiene-styrene block polymer mixture, characterized in that the mixture comprises a linear butadiene-styrene block copolymer and a linear styrene-butadiene-styrene block copolymer;

[0007] The weight ratio of the structural unit A derived from butadiene to the structural unit B derived from styrene in the mixture is 3-4:1; the weight ratio of the styrene block to the styrene non-block in the mixture is 2.3-3.6:1; the number average molecular weight of the mixture is 130,000-170,000, and the molecular weight distribution is 1-1.2.

[0008] A second aspect of the present invention provides a method for preparing a styrene-butadiene block polymer mixture, characterized in that the method comprises:

[0009] (1) in an organic hydrocarbon solvent, in the presence of a structure regulator, subjecting a butadiene monomer and a styrene monomer to a first anionic solution polymerization reaction to obtain a linear butadiene-styrene block copolymer solution;

[0010] (2) in an organic hydrocarbon solvent, in the presence of a structure regulator, subjecting styrene monomer I to a second anionic solution polymerization reaction to obtain a second polymerization product; contacting the second polymer product, butadiene monomer, and styrene monomer II to a third anionic solution polymerization reaction to obtain a linear styrene-butadiene-styrene block copolymer solution;

[0011] (3) mixing the linear butadiene styrene block copolymer solution obtained in step (1) with the linear styrene-butadiene-styrene block copolymer solution obtained in step (2) to obtain a butadiene styrene block polymer mixture solution;

[0012] (4) coagulating and drying the styrene butadiene block polymer mixture solution to obtain a styrene butadiene block polymer mixture.

[0013] The third aspect of the present invention provides a styrene-butadiene block polymer mixture prepared by the above method.

[0014] A fourth aspect of the present invention provides a use of the above-mentioned styrene-butadiene block polymer mixture as an asphalt modifier.

[0015] Through the above technical solution, the styrene-butadiene block polymer mixture provided by the present invention and its preparation method and application achieve the following beneficial effects:

[0016] The styrene butadiene block polymer mixture provided by the present invention comprises a linear styrene butadiene block copolymer with a specific structure and a linear styrene-butadiene-styrene block copolymer with a special structure. At the same time, the mixture has a specific structure, so that the styrene butadiene block polymer mixture has excellent high and low temperature performance, excellent initial adhesion and mechanical properties, and can be suitable for self-adhesive waterproof membranes. DETAILED DESCRIPTION

[0017] The endpoints of the ranges and any values 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 endpoints of each range, the endpoints of each range and individual point values, and the individual point values can be combined with each other to obtain one or more new numerical ranges, which should be considered to be specifically disclosed herein.

[0018] A first aspect of the present invention provides a styrene-butadiene block polymer mixture, characterized in that the mixture comprises a linear styrene-butadiene block copolymer and a linear styrene-butadiene-styrene block copolymer;

[0019] The weight ratio of the structural unit A derived from butadiene to the structural unit B derived from styrene in the mixture is 3-4:1; the weight ratio of the block styrene block to the non-block styrene in the mixture is 2.3-3.6:1; the number average molecular weight of the mixture is 130,000-170,000, and the molecular weight distribution is 1-1.2.

[0020] In the present invention, the styrene-butadiene block polymer mixture contains a linear styrene-butadiene block copolymer with a specific structure and a linear styrene-butadiene-styrene block copolymer with a special structure. At the same time, the mixture has a specific structure, so that the styrene-butadiene block polymer mixture has excellent high and low temperature performance, excellent initial adhesion and mechanical properties, and can be suitable for self-adhesive waterproof membranes.

[0021] In the present invention, block styrene refers to a styrene polymer formed by 5 or more consecutive styrene monomers in the molecular chain; non-block styrene refers to a styrene polymer formed by 4 or less consecutive styrene monomers in the molecular chain.

[0022] In the present invention, by controlling the weight ratio of the butadiene-derived structural units A to the styrene-derived structural units B in the mixture to meet the above range, the high and low temperature properties of the coil produced from the mixture can be balanced. If the content of the styrene-derived structural units B in the mixture is too low, the mixture will have fewer physical crosslinking points and lower hardness, resulting in poor high-temperature performance and increased needle penetration of the coil produced from the mixture. If the content of the styrene-derived structural units B in the mixture is too high, the mixture will have increased hardness and a higher glass transition temperature, resulting in poor low-temperature flexibility of the coil produced from the mixture.

[0023] In the present invention, when the weight ratio of block styrene to non-block styrene in the mixture is controlled to meet the above range, the mechanical properties and elongation of the coiled material produced from the mixture can be balanced. If the non-block styrene content in the mixture is too low, the elongation of the coiled material produced from the mixture is reduced, resulting in poor low-temperature flexibility of the coiled material; if the non-block styrene content in the mixture is too high, the mechanical properties are reduced, resulting in the coiled material produced from the mixture not meeting the required strength.

[0024] Furthermore, the weight ratio of block styrene to non-block styrene in the mixture is 2.5-3.5:1.

[0025] According to the present invention, the weight ratio of the linear butadiene styrene block copolymer to the linear styrene-butadiene-styrene block copolymer is 0.4-2:1.

[0026] In the present invention, when the weight ratio of the linear styrene butadiene block copolymer to the linear styrene-butadiene-styrene block copolymer in the mixture is controlled to meet the above range, the high- and low-temperature performance of the rubber composition containing the mixture can be significantly improved. In particular, the weight of either the linear styrene butadiene block copolymer or the linear styrene-butadiene-styrene block copolymer in the mixture is not less than 30 wt%, preferably not less than 40 wt%.

[0027] Furthermore, in the mixture, the weight ratio of the linear butadiene styrene block copolymer to the linear styrene-butadiene-styrene block copolymer is 0.6-1.5:1.

[0028] In the present invention, in the mixture, the content of 1,2-structure of butadiene is 10-16wt%, the weight ratio of 1,4-structure of butadiene to 1,2-structure of butadiene is 5.2-9:1, the content of styrene structure is 20-25wt%, and the content of block styrene is 14-20wt%.

[0029] In the present invention, by controlling the number average molecular weight and molecular weight distribution of the mixture to meet the above ranges, the mixture can have good mechanical properties while maintaining good processing properties.

[0030] Furthermore, the number average molecular weight of the mixture is 13.5-16.5, and the molecular weight distribution is 1.02-1.15.

[0031] Linear butadiene styrene block copolymer

[0032] According to the present invention, the weight ratio of the structural unit C derived from butadiene to the structural unit D derived from styrene in the linear butadiene-styrene block copolymer is 3-4:1.

[0033] In the present invention, when the weight ratio of the structural unit C derived from butadiene and the structural unit D derived from styrene in the linear butadiene-styrene block copolymer is controlled to meet the above-mentioned range, the relative contents of the structural unit A derived from butadiene and the structural unit B derived from styrene in the mixture can be controlled, and the high and low temperature properties of the coil prepared from the mixture can be balanced.

[0034] To ensure that linear butadiene styrene block copolymers have excellent mechanical properties and hardness, the content of block styrene in the linear butadiene styrene block copolymers must be greater than the content of non-block styrene. To ensure excellent ductility, the non-block styrene content should not be less than 20% by weight of the total styrene monomer content. In the present invention, the inventors achieved excellent mechanical properties, hardness, and ductility by controlling the weight ratio of block styrene to non-block styrene in the linear butadiene styrene block copolymer to 1-3:1.

[0035] Furthermore, the weight ratio of block styrene to non-block styrene in the linear butadiene styrene block copolymer is 1.8-2.6:1.

[0036] According to the present invention, the linear butadiene styrene block copolymer has a number average molecular weight of 130,000-170,000 and a molecular weight distribution of 1-1.2.

[0037] In the present invention, by controlling the number average molecular weight and molecular weight distribution of the linear butadiene styrene block copolymer to meet the above ranges, it is possible to ensure that the molecular chains of the block styrene in the mixture have an appropriate length, thereby ensuring that the coil prepared from the mixture has the required mechanical properties and hardness.

[0038] According to the present invention, the weight ratio of the 1,4-structure of butadiene to the 1,2-structure of butadiene in the linear butadiene-styrene block copolymer is 5-9:1.

[0039] In the present invention, when the weight ratio of butadiene 1,4-structure to butadiene 1,2-structure in the linear butadiene-styrene block copolymer is controlled to meet the above range, the coil prepared from the mixture can have good low-temperature performance.

[0040] Furthermore, the weight ratio of the 1,4-structure of butadiene to the 1,2-structure of butadiene in the linear butadiene-styrene block copolymer is 5.5-7.5:1.

[0041] In the present invention, in the linear butadiene-styrene block copolymer, the content of 1,2-structure of butadiene is 10-16wt%, the content of the styrene structure is 20-25wt%, and the content of block styrene is 10-19wt%.

[0042] Linear styrene-butadiene-styrene block copolymer

[0043] According to the present invention, the linear styrene-butadiene-styrene block copolymer is an asymmetric polymer.

[0044] In the present invention, the asymmetric polymer refers to a styrene-butadiene-styrene block copolymer in which the third segment of polystyrene contains a small amount of butadiene and styrene copolymer.

[0045] According to the present invention, the weight ratio of the structural unit E derived from butadiene to the structural unit F derived from styrene in the linear styrene-butadiene-styrene block copolymer is 3-4:1.

[0046] In the present invention, when the weight ratio of the structural unit E derived from butadiene and the structural unit F derived from styrene in the linear butadiene-styrene block copolymer is controlled to meet the above-mentioned range, the relative contents of the structural unit A derived from butadiene and the structural unit B derived from styrene in the mixture can be controlled, and the high and low temperature properties of the coil prepared from the mixture can be balanced.

[0047] According to the present invention, the weight ratio of block styrene to non-block styrene in the linear styrene-butadiene-styrene block copolymer is 4-6:1.

[0048] To ensure that linear styrene-butadiene-styrene block copolymers have excellent mechanical properties, the styrene block content in the linear styrene-butadiene-styrene block copolymer should not be less than 80% by weight of the total styrene monomer content. To ensure that the linear styrene-butadiene-styrene block copolymers have excellent ductility, the non-block styrene content in the styrene-butadiene-styrene block copolymers should not be less than 15% by weight of the total styrene monomer weight. In the present invention, the inventors have achieved excellent mechanical properties, hardness, and ductility by controlling the weight ratio of block styrene to non-block styrene in the linear styrene-butadiene-styrene block copolymers to 4-6:1.

[0049] Furthermore, the weight ratio of block styrene to non-block styrene in the linear butadiene styrene block copolymer is 4-5.5:1.

[0050] According to the present invention, the linear styrene-butadiene-styrene block copolymer has a number average molecular weight of 130,000-170,000 and a molecular weight distribution of 1-1.2.

[0051] In the present invention, by controlling the number average molecular weight and molecular weight distribution of the linear styrene-butadiene-styrene block copolymer to meet the above ranges, it is possible to ensure that the molecular chains of the block styrene in the mixture have an appropriate length, thereby ensuring that the coil prepared from the mixture has the required mechanical properties and hardness.

[0052] According to the present invention, the weight ratio of butadiene 1,4-structure to butadiene 1,2-structure in the linear styrene-butadiene-styrene block copolymer is 5-9:1.

[0053] In the present invention, when the weight ratio of butadiene 1,4-structure to butadiene 1,2-structure in the linear styrene-butadiene-styrene block copolymer is controlled to meet the above range, the coil prepared from the mixture can have good low temperature performance.

[0054] Furthermore, the weight ratio of the 1,4-structure of butadiene to the 1,2-structure of butadiene in the linear styrene-butadiene-styrene block copolymer is 5.5-7.5:1.

[0055] In the present invention, in the linear styrene-butadiene-styrene block copolymer, the content of 1,2-structure of butadiene is 10-16 wt %, the content of the styrene structure is 20-25 wt %, and the content of block styrene is 16-21 wt %.

[0056] A second aspect of the present invention provides a method for preparing a styrene-butadiene block polymer mixture, characterized in that the method comprises:

[0057] (1) in an organic hydrocarbon solvent, in the presence of a structure regulator, subjecting a butadiene monomer and a styrene monomer to a first anionic solution polymerization reaction to obtain a linear butadiene-styrene block copolymer solution;

[0058] (2) in an organic hydrocarbon solvent, in the presence of a structure regulator, subjecting styrene monomer I to a second anionic solution polymerization reaction to obtain a second polymerization product; contacting the second polymer product, butadiene monomer, and styrene monomer II to a third anionic solution polymerization reaction to obtain a linear styrene-butadiene-styrene block copolymer solution;

[0059] (3) mixing the linear butadiene styrene block copolymer solution obtained in step (1) with the linear styrene-butadiene-styrene block copolymer solution obtained in step (2) to obtain a butadiene styrene block polymer mixture solution;

[0060] (4) coagulating and drying the styrene butadiene block polymer mixture solution to obtain a styrene butadiene block polymer mixture.

[0061] In the present invention, a linear butadiene styrene block copolymer solution and a linear styrene-butadiene-styrene block copolymer solution are respectively prepared by anionic solution polymerization, and the two are mixed. In the state of the copolymer solution, the molecular chains of the linear butadiene styrene block copolymer and the molecular chains of the linear styrene-butadiene-styrene block copolymer can interpenetrate and entangle with each other, thereby enabling the linear butadiene styrene block copolymer and the linear styrene-butadiene-styrene block copolymer to be uniformly mixed at the microscopic level in the styrene butadiene block polymer mixture obtained by coagulation and drying, and ultimately enabling the coil prepared from the mixture to have excellent comprehensive properties.

[0062] In the present invention, the addition of a structure regulator can achieve regulation of the weight ratio of block styrene to non-block styrene in the linear butadiene styrene block copolymer and the linear styrene-butadiene-styrene block copolymer, ultimately ensuring that the weight ratio of block styrene to non-block styrene in the mixture meets the requirements of the present invention. The structure regulator is generally an ether (or amine) structure regulator, preferably an environmentally friendly ether structure regulator, and more preferably an ether structure regulator with weaker regulation ability (such as tetrahydrofuran). The amount of the structure regulator used is generally 100-200 mg / kg relative to the weight of the solvent.

[0063] According to the present invention, the step (1) comprises the following steps:

[0064] (a) conducting a first anionic solution polymerization reaction of butadiene monomer and styrene monomer in an organic hydrocarbon solvent in the presence of an organic lithium compound and a structure regulator;

[0065] (b) after the butadiene monomer and the styrene monomer are completely converted, subjecting the polymerization product solution obtained in step (a) to a termination reaction in the presence of a terminator;

[0066] (c) adding an antioxidant to the product obtained in step (b) to obtain the linear butadiene-styrene block copolymer solution.

[0067] In the present invention, a linear butadiene-styrene block copolymer is prepared according to the above method, and butadiene monomer and styrene monomer are subjected to anionic solution copolymerization to obtain a linear butadiene-styrene copolymer containing a butadiene homopolymer segment, a butadiene and styrene copolymer segment and a styrene homopolymer segment.

[0068] According to the present invention, the initiation temperature of the first anionic solution polymerization reaction is 45-55°C.

[0069] In the present invention, by controlling the initiation temperature of the first anion solution polymerization reaction to meet the above-mentioned range, not only can the maximum temperature of the polymerization reaction be controlled not to exceed 105°C to avoid the occurrence of high-temperature side reactions, but also the block styrene and non-block styrene in the obtained linear butadiene styrene block copolymer can meet the requirements of the present invention.

[0070] According to the present invention, the weight ratio of the butadiene monomer to the styrene monomer is 3-4:1.

[0071] In the present invention, the organolithium compound can be a conventional organolithium compound in the art, such as n-butyllithium. In the present invention, the amount of the organolithium compound used is 0.55-0.8 mmol / 100 g polymer.

[0072] According to the present invention, step (2) comprises the following steps:

[0073] (I) subjecting styrene monomer I to a second anionic solution polymerization reaction in the presence of an organolithium compound and a structure modifier in an organic hydrocarbon solvent to obtain a second polymerization product, and contacting the second polymerization product with a butadiene monomer and styrene monomer II to a third anionic solution polymerization reaction;

[0074] (II) subjecting the polymerization product solution obtained in step (I) to a termination reaction in the presence of a terminator;

[0075] (IV) adding an antioxidant to the polymer solution obtained in step (III).

[0076] In the present invention, the linear styrene-butadiene-styrene block polymer is prepared according to the above method by anionic solution polymerization of styrene monomer I to obtain a styrene homopolymer, and then the butadiene monomer and the styrene monomer II are anionic copolymerized to obtain a linear styrene butadiene block polymer containing a styrene homopolymer segment, a butadiene and styrene copolymer segment, and a styrene homopolymer segment.

[0077] According to the present invention, the initiation temperature of the second anionic polymerization reaction and the third anionic polymerization reaction is independently 45-55°C.

[0078] In the present invention, by controlling the initiation temperature of the second anionic solution polymerization reaction and the third anionic polymerization reaction to meet the above-mentioned range, not only can the maximum temperature of the polymerization reaction be controlled not to exceed 105° C. to avoid the occurrence of high-temperature side reactions, but also the block styrene and non-block styrene in the obtained linear styrene-butadiene-styrene block copolymer can meet the requirements of the present invention.

[0079] According to the present invention, the weight ratio of the styrene monomer I to the styrene monomer II is 0.65-1:1.

[0080] In the present invention, by controlling the weight ratio of styrene monomer I to styrene monomer II to meet the above range, the obtained linear styrene-butadiene-styrene copolymer can obtain better mechanical properties.

[0081] Furthermore, the weight ratio of the styrene monomer I to the styrene monomer II is 0.7-0.9:1.

[0082] According to the present invention, the weight ratio of the butadiene monomer to the total weight of the styrene monomer I and the styrene monomer II is 3-4:1.

[0083] In the present invention, the organic lithium compound can be a conventional organic lithium compound in the art, such as n-butyl lithium. In the present invention, the amount of the organic lithium compound used is 0.55-0.8 mmol / g polymer.

[0084] According to the present invention, the amount of the antioxidant is 0.3-0.6 parts by weight relative to 100 parts by weight of the total weight of the butadiene monomer and the styrene monomer.

[0085] In the present invention, in order to enable the styrene-butadiene block polymer mixture to meet the application requirements of the self-adhesive waterproof membrane, the boiling point of the antioxidant is above 220°C.

[0086] According to the present invention, the antioxidant is selected from antioxidant 1135 and / or antioxidant 1076. More preferably, the antioxidant is a composite antioxidant of antioxidant 1135 and antioxidant 1076, wherein the weight ratio of the antioxidant 1135 to the antioxidant 1076 is 0.5-2:1.

[0087] The third aspect of the present invention provides a styrene-butadiene block polymer mixture prepared by the above method.

[0088] A fourth aspect of the present invention provides a use of the above-mentioned styrene-butadiene block polymer mixture as an asphalt modifier.

[0089] According to the present invention, the styrene-butadiene block polymer mixture is used as an asphalt modifier in at least one of a self-adhesive modified asphalt waterproofing membrane, a hot-melt modified asphalt waterproofing membrane and a low-temperature resistant road modified asphalt.

[0090] In the present invention, the styrene butadiene block polymer mixture is used as a modifier to prepare a self-adhesive waterproof membrane. The self-adhesive waterproof membrane comprises 100 parts of asphalt, 6-12 parts of the styrene butadiene block polymer mixture, 40-60 parts of rubber oil and 5-15 parts of talc.

[0091] The present invention will be described in detail below through examples.

[0092] The 1,2-structural unit content, 1,4-structural unit content, styrene content, block styrene content and non-block styrene content of styrene-butadiene block polymer were measured by Bruker AVANCE400 superconducting nuclear magnetic resonance instrument ( 1 H-NMR) test, 1The resonance frequency of the H nucleus is 300.13 MHz, the spectral width is 2747.253 Hz, the pulse width is 5.0 μs, the data point is 16 K, the sample tube diameter is 5 mm, the solvent is deuterated chloroform CDCl3, the sample concentration is 15% (W / V), the test temperature is room temperature, the number of scans is 16 times, and the calibration is based on the chemical shift of tetramethylsilane as 0 ppm.

[0093] The molecular weight and molecular weight distribution of the styrene butadiene block polymer were determined using an HLC-8320 gel permeation chromatograph manufactured by Tosoh Corporation of Japan. The test conditions included: a TSKgel Super Multipore HZ-N column, a TSKgel Super Multipore HZ standard column, chromatographically pure THF as the solvent, polystyrene as the calibration standard, a sample concentration of 1 mg / ml, an injection volume of 10.00 μl, a flow rate of 0.35 ml / min, and a test temperature of 40.0°C.

[0094] The softening point of modified asphalt was measured using an HDLR-IV asphalt high temperature softening point tester.

[0095] The initial adhesion performance of modified asphalt was measured using the LT-3000 ring initial adhesion tester.

[0096] The peel strength of modified asphalt was measured using a BLD-200S electronic peel tester.

[0097] Experimental apparatus and process: The experiment was carried out in a 5L polymerization reactor. The solvent, butadiene and styrene monomers were added from the polymerization pipeline. The initiator and structure regulator were added from the top of the polymerization reactor using a syringe. After the polymerization was completed, the polymer was treated with water vapor and dried on a plasticator to obtain a butadiene-styrene block polymer composition.

[0098] The pressures mentioned in this experiment refer to gauge pressure.

[0099] Antioxidant 1135 and antioxidant 1076 were purchased from Inotech Reagent Company;

[0100] Cyclohexane was purchased from Sinopharm Reagent Company with a purity of >99.9 and was soaked in molecular weight sieves for 15 days with a water content of less than 5 ppm;

[0101] Styrene, polymer grade, sourced from Yanshan Petrochemical;

[0102] Butadiene, polymer grade, sourced from Yanshan Petrochemical;

[0103] Butyl lithium (Li) was purchased from J&K Reagent Co., Ltd., 100 ml, 1.6 mol·L -1 Cyclohexane solution, diluted to 0.4 mol·L -1 Cyclohexane solution;

[0104] Tetrahydrofuran (THF) was purchased from J&K Reagent Co., Ltd., 500 g, chromatographic grade;

[0105] SBS4303, provided by Sinopec Beijing Yanshan Branch, has a number average molecular weight of 10.8, a molecular weight distribution of 1.64, a 1,2-structure content of butadiene of 12.8 wt%, a weight ratio of 1,4-structure of butadiene to 1,2-structure of butadiene of 6.81, a content of structural units derived from styrene of 30.2 wt%, a weight ratio of structural units derived from butadiene to structural units derived from styrene of 2.31, a block styrene content of 29.6 wt%, and a weight ratio of block styrene to non-block styrene of 49.3;

[0106] SBS4402, provided by Sinopec Beijing Yanshan Branch, has a number average molecular weight of 10.1, a molecular weight distribution of 1.48, a 1,2-structure content of butadiene of 13.2wt%, a weight ratio of 1,4-structure of butadiene to 1,2-structure of butadiene of 6.58, a content of structural units derived from styrene of 40.6wt%, a weight ratio of structural units derived from butadiene to structural units derived from styrene of 1.46, a content of block styrene of 39.5wt%, and a weight ratio of block styrene to non-block styrene of 35.9.

[0107] Example 1

[0108] This embodiment is used to illustrate the styrene-butadiene block polymer mixture and its preparation method of the present invention.

[0109] Under nitrogen protection, cyclohexane solvent, structure regulator tetrahydrofuran, 1,3-butadiene and styrene monomers (types and amounts are shown in Table 1, and the amounts listed in the table are measured based on pure compounds) were added to a 5L reactor, and the initiation reaction temperature was controlled within the range of 45-55°C. A designed amount of n-butyl lithium (amount is shown in Table 1, and the amounts listed in the table are measured based on pure compounds) was added to the 5L reactor, and the maximum polymerization temperature was controlled within the range of 90-105°C. After the polymerization was completed, excess water was added to terminate the polymerization, and then a composite antioxidant of 1135 and 1076 in a weight ratio of 1:1, which was 0.4wt% of the total weight of the monomers, was added to finally obtain a butadiene-styrene block copolymer solution LBS1, which was analyzed and tested. The results are shown in Table 2.

[0110] Under nitrogen protection, cyclohexane solvent, structure regulator tetrahydrofuran, and styrene monomer I (types and amounts are shown in Table 3, and the amounts listed in the table are measured based on pure compounds) were added to a 5L reactor, the initiation reaction temperature was controlled within the range of 45-55°C, and a designed amount of n-butyl lithium (amounts are shown in Table 3, and the amounts listed in the table are measured based on pure compounds) was added to the 5L reactor. After the first stage of styrene polymerization was completed, the mixed butadiene monomer and styrene monomer II were added to the 5L reactor until the monomers were completely converted. After the polymerization was completed, excess water was added to terminate the polymerization, and then 0.4 wt% of the total weight of the monomers and a composite antioxidant of 1135 and 1076 in a weight ratio of 1:1 were added to finally obtain a styrene-butadiene-styrene block polymer solution SBS1, which was analyzed and tested. The results are shown in Table 4.

[0111] LBS1 and SBS1 were mixed in a weight ratio of 1:1, and then condensed by steam and dried in a plastic machine to prepare a styrene-butadiene block polymer mixture ZSB1. The mixture was then analyzed and tested, and the results are shown in Table 5.

[0112] Examples 2-7

[0113] This embodiment is used to illustrate the styrene-butadiene block polymer mixture and its preparation method of the present invention.

[0114] The method described in Example 1 is the same, except that the parameters shown in Table 1 are used to prepare linear styrene butadiene copolymers, thereby obtaining linear styrene butadiene copolymer solutions LBS2-LBS7, respectively. The analysis and test results are shown in Table 2; the parameters shown in Table 3 are used to prepare linear styrene-butadiene-styrene block polymers, thereby obtaining linear styrene-butadiene-styrene block polymer solutions SBS2-SBS7, respectively. The analysis and test results are shown in Table 4; LBS2-LBS7 and SBS2-SBS7 are mixed in a weight ratio of 1:1, and then condensed by water vapor and dried in a plastic machine to obtain styrene butadiene block polymer mixtures ZSB2-ZSB7, which are then analyzed and tested, and the results are shown in Table 5.

[0115] Comparative Examples 1-4

[0116] The method described in Example 1 is as follows, except that the parameters shown in Table 1 are used to prepare linear styrene butadiene copolymers, thereby obtaining linear styrene butadiene copolymer solutions DLBS1-DLBS4, respectively. The analysis and test results are shown in Table 2; the parameters shown in Table 3 are used to prepare linear styrene-butadiene-styrene block polymers, thereby obtaining linear styrene-butadiene-styrene block polymer solutions DSBS1-DSBS4, respectively. The analysis and test results are shown in Table 4; DLBS1-DLBS4 and DSBS1-DSBS4 are mixed in a weight ratio of 1:1, then condensed by water vapor and dried in a plastic machine to obtain styrene butadiene block polymer mixtures DZSB1-DZSB4, which are then analyzed and tested. The results are shown in Table 5.

[0117] Table 1

[0118]

[0119]

[0120] Table 2

[0121]

[0122] Table 3

[0123]

[0124] Table 4

[0125]

[0126]

[0127] Table 5

[0128]

[0129] As can be seen from Table 5, the styrene-butadiene block polymer mixture prepared in the present invention has a low styrene content and a high block styrene content, so that the mixture has excellent high and low temperature performance, mechanical properties and ductility, and can be used as a modified polymer for waterproof membranes.

[0130] Example 8

[0131] This example is used to illustrate the application of the styrene-butadiene block polymer mixture prepared by the present invention in a self-adhesive waterproof membrane.

[0132] Self-adhesive waterproof membranes were prepared using the styrene butadiene block polymer mixtures ZSB1-ZSB7 described in Examples 1-7, comprising 50 parts of an asphalt base, 10 parts of a styrene butadiene block polymer mixture, 15 parts of rubber oil, and 25 parts of talc. The test results of the prepared membranes are shown in Table 6.

[0133] Comparative Example 5

[0134] The modified asphalt roll was prepared by the same method as in Example 8, except that DZSB1-DZSB4 were used instead of ZSB1. The test results of the prepared rolls are shown in Table 6.

[0135] Comparative Example 6

[0136] The modified asphalt roll was prepared by the same method as in Example 8, except that commercially available SBS grades 4303 and 4402 were used instead of ZSB1. The test results of the prepared roll are shown in Table 6.

[0137] Table 6

[0138]

[0139] It can be seen from Table 6 that the self-adhesive waterproof membrane prepared by using the butadiene-styrene block polymer mixture of the present invention as a modifier has excellent low-temperature performance, peel strength and sustained adhesion performance.

[0140] The preferred embodiments of the present invention have been described in detail above, but the present invention is not limited thereto. Within the technical concept of the present invention, various simple variations of the technical solution of the present invention may be made, including combining the various technical features in any other appropriate manner. These simple variations and combinations should also be regarded as disclosed in the present invention and fall within the scope of protection of the present invention.

Claims

1. A styrene-butadiene block polymer mixture, characterized in that: The mixture comprises a linear butadiene-styrene block copolymer and a linear styrene-butadiene-styrene block copolymer; The weight ratio of the structural unit A derived from butadiene to the structural unit B derived from styrene in the mixture is 3-4:1; the weight ratio of the block styrene to the non-block styrene in the mixture is 2.3-3.6:1; the number average molecular weight of the mixture is 130,000-170,000, and the molecular weight distribution is 1-1.2; The weight ratio of block styrene to non-block styrene in the linear butadiene styrene block copolymer is 1-3:1; The weight ratio of block styrene to non-block styrene in the linear styrene-butadiene-styrene block copolymer is 4-6:1; The block styrene refers to a styrene polymer formed by more than 5 consecutive styrene monomers in the molecular chain; the non-block styrene refers to a styrene polymer formed by less than 4 consecutive styrene monomers in the molecular chain.

2. The styrene-butadiene block polymer mixture according to claim 1, wherein The weight ratio of the linear butadiene styrene block copolymer to the linear styrene-butadiene-styrene block copolymer is 0.4-2:

1.

3. The styrene-butadiene block polymer mixture according to claim 1 or 2, wherein The weight ratio of the structural unit C derived from butadiene to the structural unit D derived from styrene in the linear butadiene-styrene block copolymer is 3-4:1; and / or, the number average molecular weight of the linear styrene-butadiene block copolymer is 130,000-170,000; And / or, the weight ratio of 1,4-butadiene structure to 1,2-butadiene structure in the linear butadiene-styrene block copolymer is 5-9:

1.

4. The styrene-butadiene block polymer mixture according to claim 1 or 2, wherein The linear styrene-butadiene-styrene block copolymer is an asymmetric polymer; and / or, the weight ratio of the structural unit E derived from butadiene to the structural unit F derived from styrene in the linear styrene-butadiene-styrene block copolymer is 3-4:1; and / or, the number average molecular weight of the linear styrene-butadiene-styrene block copolymer is 130,000-170,000; And / or, the weight ratio of 1,4-butadiene structure to 1,2-butadiene structure in the linear styrene-butadiene-styrene block copolymer is 5-9:

1.

5. A method for preparing the styrene-butadiene block polymer mixture according to any one of claims 1 to 4, characterized in that: The method comprises: (1) In an organic hydrocarbon solvent, in the presence of a structure regulator, butadiene monomer and styrene monomer undergo a first anionic solution polymerization reaction to obtain a linear butadiene-styrene block copolymer solution; (2) In an organic hydrocarbon solvent, in the presence of a structure regulator, styrene monomer I undergoes a second anionic solution polymerization reaction to obtain a second polymerization product, and the second polymerization product, butadiene monomer, and styrene monomer II are contacted and subjected to a third anionic solution polymerization reaction to obtain a linear styrene-butadiene-styrene block copolymer solution; (3) mixing the linear butadiene styrene block copolymer solution obtained in step (1) with the linear styrene-butadiene-styrene block copolymer solution obtained in step (2) to obtain a butadiene styrene block polymer mixture solution; (4) The styrene butadiene block polymer mixture solution is condensed and dried to obtain a styrene butadiene block polymer mixture.

6. The method for preparing the styrene-butadiene block polymer mixture according to claim 5, wherein The step (1) comprises the following steps: (a) in an organic hydrocarbon solvent, in the presence of an organic lithium compound and a structure regulator, a butadiene monomer and a styrene monomer undergo a first anionic solution polymerization reaction; (b) after the butadiene monomer and the styrene monomer are completely converted, subjecting the polymerization product solution obtained in step (a) to a termination reaction in the presence of a terminator; (c) adding an antioxidant to the product obtained in step (b) to obtain the linear butadiene-styrene block copolymer solution.

7. The preparation method according to claim 5 or 6, wherein The initiation temperature of the first anionic solution polymerization reaction is 45-55°C; And / or, the weight ratio of the butadiene monomer to the styrene monomer is 3-4:

1.

8. The preparation method according to claim 5 or 6, wherein The step (2) includes the following steps: (I) in an organic hydrocarbon solvent, in the presence of an organic lithium compound and a structure regulator, subjecting styrene monomer I to a second anionic solution polymerization reaction to obtain a second polymerization product, and contacting the second polymerization product with a butadiene monomer and styrene monomer II to a third anionic solution polymerization reaction; (II) subjecting the polymerization product solution obtained in step (I) to a termination reaction in the presence of a terminator; (IV) Adding an antioxidant to the polymer solution obtained in step (III).

9. The preparation method according to claim 8, wherein The initiation temperature of the second anionic polymerization reaction and the third anionic polymerization reaction is independently 45-55° C.; and / or, the weight ratio of the styrene monomer I to the styrene monomer II is 0.65-1:1; And / or, the ratio of the butadiene monomer to the total weight of the styrene monomer I and the styrene monomer II is 3-4:

1.

10. The preparation method according to claim 6, wherein The amount of the antioxidant is 0.3-0.6 parts by weight relative to 100 parts by weight of the total weight of the butadiene monomer and the styrene monomer; And / or, the antioxidant is selected from antioxidant 1135 and / or antioxidant 1076.

11. The preparation method according to claim 10, wherein The antioxidant is a composite antioxidant of antioxidant 1135 and antioxidant 1076, and the weight ratio of the antioxidant 1135 to the antioxidant 1076 is 0.5-2:

1.

12. Use of the styrene-butadiene block polymer mixture according to any one of claims 1 to 4 as an asphalt modifier.

13. The use according to claim 12, wherein: The styrene-butadiene block polymer mixture is used as an asphalt modifier in at least one of a self-adhesive modified asphalt waterproofing membrane, a hot-melt modified asphalt waterproofing membrane and a low-temperature resistant road modified asphalt.

Images