阅读说明：本技术 一种官能化sebs及其制备方法 (Functionalized SEBS and preparation method thereof ) 是由 李嵬 卢俊典 朱思琪 刘歌 于胜楠 刘晓杰 陈二中 燕晓宇 孙梦垚 张娇 于 2020-07-13 设计创作，主要内容包括：本发明涉及苯乙烯类热塑性弹性体,具体涉及一种硅氧/胺基官能化SEBS及其制备方法。官能化SEBS为硅氧/胺基官能化热塑性弹性体SBS的氢化物,其数均分子量为1×10<Sup>4</Sup>-1×10<Sup>6</Sup>,分子量分布为1.0-1.5,按照质量百分比,苯乙烯单元的含量占0-50％,丁二烯单元的含量占50-100％,每个分子链上含有1-20个硅氧/胺基基团。本发明所得的硅氧/胺基官能化SEBS在具备优异的热氧安定性的前提下,大幅改善了与极性材料的相容性,显著提升了复合材料的韧性和抗冲击性能。(The invention relates to a styrene thermoplastic elastomer, and in particular relates to a silica/amino functionalized SEBS and a preparation method thereof. The functionalized SEBS is a hydride of a silicone/amino functionalized thermoplastic elastomer SBS with a number average molecular weight of 1 × 10 4 ‑1×10 6 The molecular weight distribution is 1.0-1.5, according to the mass percentage, the content of styrene unit accounts for 0-50%, the content of butadiene unit accounts for 50-100%, and each molecular chain contains 1-20 silica/amino groups. On the premise of excellent thermal-oxidative stability, the silicone/amino functionalized SEBS provided by the invention greatly improves the compatibility with polar materials and obviously improves the toughness and impact resistance of the composite material.)

1. A functionalized SEBS characterized by: the functionalized SEBS is a hydride of a silicone/amino functionalized thermoplastic elastomer SBS with a number average molecular weight of 1 × 10⁴-1×10⁶The molecular weight distribution is 1.0-1.5, according to the mass percentage, the content of styrene unit accounts for 0-50%, the content of butadiene unit accounts for 50-100%, and each molecular chain contains 1-20 silica/amino groups; the structure of the hydrogenated precursor of the copolymer is: omega-end-DPE-Si (OR)_nR’_3-n/SBS、in-DPE-Si(OR)_nR’_3-n/SBS、ω-end-DPE-(NR₂)_m/SBS、in-DPE-(NR₂)_m/SBS。

2. The functionalized SEBS of claim 1, wherein: the structure of the hydrogenated precursor of the copolymer is: chain end functionalized thermoplastic elastomer omega-end-DPE-Si (OR)_nR’_3-n/SBS、ω-end-DPE-(NR₂)_mSBS or in-chain functionalized thermoplastic elastomer in-DPE-Si (OR)_nR’_3-n/SBS、in-DPE-(NR₂)_mSBS, wherein: SBS is a triblock polymer of styrene (S) -butadiene (B) -styrene (S), omega-end-DPE-Si (OR)_nR’_3-nomega-end-DPE- (NR) monomers functionalized with Si-O groups to link the polymer chain ends₂)_mFor the purpose of attaching at the end of the polymer chain an amino-functional DPE monomer, in-DPE-Si(OR)_nR’_3-nin-DPE- (NR) monomers functionalized with Si-O groups bound in the polymer chain₂)_mFor amine functional DPE monomers attached to the polymer chain, R and R' may be the same or different and are selected from methyl or ethyl, n is the number of attached siloxy groups per DPE, n is 1 to 3, m is the number of attached amine groups per DPE, and m is 1 or 2.

3. The functionalized SEBS of claim 2, wherein: the SBS chain segment in the hydrogenated precursor comprises 0-50% of the total monomer mass of S and 50-100% of B.

4. A process for the preparation of functionalized SEBS according to claim 1, characterized in that:

1) dissolving silica/amino functionalized DPE in a nonpolar organic solvent, and adding an initiator to prepare a silica/amino functionalized initiator; 2) adding styrene (S), butadiene (B) and styrene into the system obtained in the step 1) in sequence to carry out polymerization reaction, and finally adding a silicone/amino functionalized end cap to obtain a chain-end silicone/amino functionalized SBS solution; 3) and (3) carrying out hydrogenation modification on the chain end siloxane/amino functionalized SBS solution obtained in the step 2) to obtain chain end siloxane/amino functionalized SEBS.

5. A process for the preparation of functionalized SEBS according to claim 4, characterized in that:

the chain-end silicon oxygen/amino functionalized SBS solution is

A: adding styrene as monomer into non-polar hydrocarbon solvent, stirring, adding amino functionalized lithium initiator, and polymerizing at 20-90 deg.C to obtain chain end amino functionalized PS (omega-end-DPE- (NR)₂)_m/PS), then adding a PB segment for polymerizing butadiene and finally adding a PS segment for polymerizing styrene to obtain the SBS (omega-end-DPE- (NR) with functionalized chain end amino₂)_m/SBS)；

The amido functionalized lithium initiator is prepared by premixing and aging an amido functionalized compound and alkyl lithium; said amine functionThe chemical compound being DPE- (NR)₂)_mWherein the mass ratio of the total monomers to the nonpolar hydrocarbon solvent is 1: 3-20; the addition amount of alkyl lithium is 1X 10^-4-1×10^-2mol/100g total monomer;

or styrene, butadiene and styrene are used as monomers, SBS is obtained by three-stage feeding polymerization, amino functionalized DPE can be added in the three-stage feeding process, and polymerization reaction is carried out at 20-90 ℃ to obtain SBS (in-DPE- (NR) with amino functionalized chain₂)_mSBS); wherein the mass ratio of the total monomers to the nonpolar hydrocarbon solvent is 1: 3-20; the lithium initiator is added in an amount of 1X 10^-4-1×10^-2mol/100g total monomer;

or adding styrene as monomer into nonpolar hydrocarbon solvent, stirring, adding silica-functionalized lithium initiator, and performing polymerization reaction at 20-90 deg.C to obtain chain-end silica-functionalized PS (omega-end-DPE-Si (OR))_nR’_3-nPS), adding a PB segment for polymerizing butadiene, and finally adding a PS segment for polymerizing styrene to obtain SBS with chain end silicon-oxygen functionalized; wherein the mass ratio of the total monomers to the nonpolar hydrocarbon solvent is 1: 3-20; the addition amount of alkyl lithium is 1X 10^-4-1×10^-2mol/100g total monomer;

or styrene, butadiene and styrene are used as monomers, SBS is obtained by three-section feeding polymerization, silica functionalized DPE can be added in the three-section feeding process, and the polymerization reaction is carried out at the temperature of 20-90 ℃, thus obtaining the SBS with silica functionalized in the chain. Wherein the mass ratio of the total monomers to the nonpolar hydrocarbon solvent is 1: 3-20; the lithium initiator is added in an amount of 1X 10^-4-1×10^-2mol per 100g of total monomers.

6. A process for the preparation of functionalized SEBS according to claim 4, characterized in that: when the chain end silicone oxygen/amino functionalized SBS solution is prepared, a polar additive is added into the system to adjust the microstructure of the system.

7. A process for the preparation of functionalized SEBS according to claim 4, characterized in that: and 3) adding a hydrogenation catalyst into the SBS functionalized by the silicon oxygen/amino group obtained in the step 3) as a hydrogenation precursor, uniformly mixing, introducing hydrogenation, carrying out hydrogenation reaction at the temperature of 10-80 ℃ and the hydrogen pressure of 1.0-6.0MPa, and removing the hydrogenation catalyst after the reaction to obtain the SEBS functionalized by the silicon oxygen/amino group at the chain end or in the chain.

8. A process for the preparation of functionalized SEBS according to claim 4, characterized in that: the nonpolar hydrocarbon solvent is one or two of n-hexane, cyclohexane, xylene, toluene, ethylbenzene, pentane, heptane, octane or raffinate oil;

the molecular formula of the alkyl lithium is RLi, R is C₄-C₂₀Alkyl group of (1).

9. A process for the preparation of functionalized SEBS according to claim 6, characterized in that: the polar additive is one or more of oxygen-containing polar compounds, nitrogen-containing polar compounds or alkoxy metal compounds.

10. Use of the functionalized SEBS of claim 1 as an interfacial compatibilizer.

Technical Field

The invention relates to a styrene thermoplastic elastomer, and in particular relates to a silica/amino functionalized SEBS and a preparation method thereof.

Background

Styrene-butylene/butylene-styrene (SEBS) is a styrene thermoplastic elastomer, soft and hard chain segments exist in the molecular chain of the elastic material, and the characteristic that mutually-penetrated soft and hard phases exist in the material matrix is realized. At normal temperature, the hard chain segment is used as a cross-linking point to inhibit the flow of the soft chain segment, and the material has high elasticity; at high temperatures, the hard segments flow and the material as a whole exhibits thermoplasticity. The material is prepared by hydrogenating and modifying styrene-butadiene-styrene (SBS). Because unstable double bonds in SBS are eliminated by hydrogenation reaction, SEBS not only has plasticity, high elasticity and high strength of SBS, but also has excellent aging resistance, and can be widely used for producing high-grade elastomers, plastic modification, adhesives, lubricating oil tackifiers, fillers and sheath materials of wires and cables, and the like.

The industrial production of SEBS is mature, the yield of SEBS from the Cocotam company in the United states reaches 62kt/a in 1997, and the SEBS increases at a speed of 7-8% every year, so that the SEBS manufacturer with the largest world production scale becomes. At that time, Taiwan in China also started to put SEBS into production, but the annual output is low and is only 20 kt/a. With the development of SEBS in China, the Ling petrochemical company also starts to join the line, and is put into production formally in 2002, so that the blank of SEBS materials in China is filled. Although China has a certain SEBS production scale, the SEBS is nonpolar and difficult to be compatible with polar materials, and the application range of the SEBS is greatly limited. Thus, modification of its polarity is a key to solving this problem. There are three main types of methods for modifying the polarity reported: firstly, adding a polar terminator at the end of anionic polymerization; secondly, adopting a thermoplastic elastomer (macroinitiator) containing carbon-carbon weak bonds, and then carrying out reactive extrusion with a polar monomer; thirdly, the elastomer is subjected to post-treatment modification such as maleic anhydride grafting, sulfonation, acetylation and the like. Wherein, the first method and the second method have strict requirements on the preparation process and have higher requirement on the purity of the monomer. Although the method III is flexible, except the maleic anhydride grafted styrene thermoplastic elastomer, the success cases of large-scale industrial application are also less. It is seen that a simple and efficient solution to polarization is highly desirable for a variety of applications.

Disclosure of Invention

In order to overcome the defects in the prior art, the invention provides a silicone/amino functionalized SEBS thermoplastic elastomer, and also provides a preparation method of the SEBS and application of the SEBS as an interface compatilizer.

In order to realize the purpose, the technical scheme is as follows:

a silicone/amino functionalized SEBS thermoplastic elastomer, wherein the total number average molecular weight of the SEBS is 1 x 10⁴-1×10⁶The molecular weight distribution is 1.0-1.5, according to the mass percentage, the content of styrene unit is 0-50%, the content of butadiene unit is 50-100%, and each polymer arm contains 1-20 silica/amino groups. The structure of the hydrogenated precursor of the copolymer is: terminal siloxy functionalized thermoplastic elastomer omega-end-DPE-Si (OR)_nR’_3-nSBS, in-chain silicone-functionalized thermoplastic elastomer in-DPE-Si (OR)_nR’_3-n[ omega ] -end-DPE- (NR) of a/SBS, terminal amino-functionalized thermoplastic elastomer₂)_mSBS, in-DPE- (NR) thermoplastic elastomer with amino functional group in chain₂)_mand/SBS. Wherein: SBS is a triblock polymer of styrene (S) -butadiene (B) -styrene (S), omega-end-DPE-Si (OR)_nR’_3-nomega-end-DPE- (NR) monomers functionalized with Si-O groups to link the polymer chain ends₂)_mTo an amino-functional DPE monomer attached at the end of the polymer chain, in-DPE-Si (OR)_nR’_3-nin-DPE- (NR) monomers functionalized with Si-O groups bound in the polymer chain₂)_mFor amine functional DPE monomers attached to the polymer chain, R and R' may be the same or different and are selected from methyl or ethyl, n is the number of attached siloxy groups per DPE, n is 1 to 3, m is the number of attached amine groups per DPE, and m is 1 or 2.

The SBS chain segment in the hydrogenated precursor comprises 0-50% of the total monomer mass of S and 50-100% of B.

The hydrogenation precursor has a butadiene monomer hydrogenation degree of greater than 95% and a styrene unit hydrogenation degree of less than 5%.

Due to the introduction of a siloxy functional monomer DPE-Si (OR) at the chain end or in the chain of the polymer_nR’_3-Or an amine-functional monomer DPE- (NR)₂)_mThe purpose of controlling the quantity and the position of the silicon-oxygen/amino functionalized monomer in the SEBS is realized, and the polarity controllability of the thermoplastic elastomer is further realized.

The chain end or mid-chain silicone/amine functionalized SEBS of the present invention has a higher, more controlled polarity than the non-functionalized non-polar thermoplastic elastomer.

A preparation method of silica/amino functionalized SEBS comprises the following steps:

1) dissolving silica/amino functionalized DPE in a nonpolar organic solvent, and adding an initiator to prepare a silica/amino functionalized initiator; 2) adding styrene (S), butadiene (B) and styrene into the system obtained in the step 1) in sequence to carry out polymerization reaction, and finally adding a silicone/amino functionalized end cap to obtain a chain-end silicone/amino functionalized SBS solution; 3) and (3) carrying out hydrogenation modification on the chain end siloxane/amino functionalized SBS solution obtained in the step 2) to obtain chain end siloxane/amino functionalized SEBS.

Further, the method comprises the following steps of;

obtaining the chain end siloxy/amino functionalized SBS, namely obtaining a system A which specifically comprises:

chain-end amine functionalized SBS (omega-end-DPE- (NR)₂)_mSBS) preparation: styrene is used as monomer, mixed with polar additive and added into non-polar hydrocarbon solventAfter being stirred evenly, the amine functionalized lithium initiator is added to carry out polymerization reaction at the temperature of 20-90 ℃ to prepare the chain end amine functionalized PS (omega-end-DPE- (NR)₂)_m/PS), then adding a PB segment for polymerizing butadiene and finally adding a PS segment for polymerizing styrene to obtain the SBS (omega-end-DPE- (NR) with functionalized chain end amino₂)_m/SBS)；

The amido functionalized lithium initiator is prepared by premixing and aging an amido functionalized compound and alkyl lithium; the amine-functional compound is DPE- (NR)₂)_mPreferably, it is a mono-or di-amine functionalized DPE. The monomer is synthesized by converting relevant benzophenone derivatives into stilbene derivatives through one-step Wittig reaction under anhydrous and oxygen-free conditions. Wherein the mass ratio of the total monomers to the nonpolar hydrocarbon solvent is 1: 3-20; the addition amount of alkyl lithium is 1X 10^-4-1×10^-2mol per 100g total monomer, the molar ratio of polar additive to alkyl lithium is 0-40: 1; alkyl lithium, preferably n-butyl lithium and sec-butyl lithium.

SBS (in-DPE- (NR) with functionalized amine groups in the chain₂)_mSBS) preparation: styrene, butadiene and styrene are used as monomers, SBS is obtained by three-stage feeding polymerization, amino functionalized DPE can be added in the three-stage feeding process, a polar additive can be selectively added to adjust the microstructure of the butadiene chain end, and polymerization reaction is carried out at 20-90 ℃ to obtain the amino functionalized SBS (in-DPE- (NR) in the chain₂)_mSBS). Wherein the mass ratio of the total monomers to the nonpolar hydrocarbon solvent is 1: 3-20; the lithium initiator is added in an amount of 1X 10^-4-1×10^-2mol per 100g total monomer, the molar ratio of polar additive to lithium initiator is 0-40: 1;

chain end siloxy functionalized SBS (. omega. -end-DPE-Si (OR))_nR’_3-nSBS) preparation: styrene is taken as a monomer, mixed with a polar additive and added into a nonpolar hydrocarbon solvent, after being uniformly stirred, a silicon-oxygen functionalized lithium initiator is added, and polymerization reaction is carried out at the temperature of 20-90 ℃ to prepare PS (omega-end-DPE-Si (OR))_nR’_3-n/PS), polymerization of P with additional butadieneAnd a B section, and finally adding a PS section for styrene polymerization to obtain the SBS with the chain end silicon-oxygen functionalized. Wherein the mass ratio of the total monomers to the nonpolar hydrocarbon solvent is 1: 3-20; the addition amount of alkyl lithium is 1X 10^-4-1×10^{- 2}mol per 100g total monomer, the molar ratio of polar additive to alkyl lithium is 0-40: 1; alkyl lithium, preferably n-butyl lithium and sec-butyl lithium.

In-chain siloxane-functionalized SBS (in-DPE-Si (OR)_nR’_3-nStyrene, butadiene and styrene are taken as monomers, SBS is obtained by three-section feeding polymerization, silica functionalized DPE can be added in the three-section feeding process, a polar additive can be selectively added to adjust the microstructure of the end of the butadiene chain, and the polymerization reaction is carried out at the temperature of 20-90 ℃, thus obtaining the silica functionalized SBS in the chain. Wherein the mass ratio of the total monomers to the nonpolar hydrocarbon solvent is 1: 3-20; the lithium initiator is added in an amount of 1X 10^-4-1×10^-2mol per 100g total monomer, the molar ratio of polar additive to lithium initiator is 0-40: 1;

meanwhile, in the preparation of different A systems, the polar additive in the system can be added or not added.

Further, the step 3) of taking the obtained silica/amino functionalized SBS as a hydrogenation precursor, adding a hydrogenation catalyst, uniformly mixing, introducing hydrogenation, carrying out hydrogenation reaction at the temperature of 10-80 ℃ and the hydrogen pressure of 1.0-6.0MPa, and removing the hydrogenation catalyst after reaction to obtain the chain end or in-chain silica/amino functionalized SEBS.

The hydrogenation of the polymer in step 3) may be carried out by any suitable hydrogenation method, and the hydrogenation catalyst comprises a compound of group VIII (i.e. Fe, Co, Ni, especially Ni) of the periodic Table, a compound of the titanium metallocene type or a compound containing a noble metal. Concretely, n-butyl lithium is added into silica/amino functionalized SBS glue solution, then hydrogen is introduced, lithium hydride is generated, titanocene dichloride is added, and 1-4MPa hydrogen is introduced for hydrogenation reaction. The reaction temperature is 30-90 ℃, and the dosage of the main catalyst dichlorotitanocene is as follows: 0.1 to 5.0mmol per 100g of polymer; the dosage of the cocatalyst n-butyllithium: the molar ratio of the n-butyllithium to the titanocene dichloride is 2-15: 1.

The nonpolar hydrocarbon solvent is one or two of n-hexane, cyclohexane, xylene, toluene, ethylbenzene, pentane, heptane, octane or raffinate oil. Preferably: cyclohexane.

The molecular formula of the alkyl lithium is RLi, R is C₄-C₂₀Alkyl group of (1). N-butyllithium or sec-butyllithium is preferred.

The polar additive is one or more of oxygen-containing polar compounds, nitrogen-containing polar compounds or alkoxy metal compounds. Preferably: an oxygen-containing polar additive;

the oxygen-containing polar additive is diethyl ether, tetrahydrofuran, R₁OCH₂CH₂OR₂、R₁OCH₂CH₂OCH₂CH₂OR₂Ethylene glycol dimethyl ether, ethylene glycol diethyl ether, diethylene glycol dimethyl ether or diethylene glycol diethyl ether; wherein R is₁、R₂Identical or different from C₁-C₆Alkyl groups of (a); preferably: tetrahydrofuran;

the nitrogen polar compound is tetramethyl ethylene diamine, triethylamine or dipiperidine ethane; preferably: tetramethylethylenediamine;

the metal alkoxide compound is ROM, wherein R is C₁-C₁₀Alkyl or C₆-C₂₀O is an oxygen atom, and M is Na or K. Potassium tert-butoxide or potassium tert-pentoxide are preferred.

The silicone/amine functional compound is preferably a silicone functional DPE, a mono-amine functional DPE, or a di-amine functional DPE.

The hydrogenation reaction ensures that the hydrogenation degree of unsaturated double bonds of diolefin in the copolymer is more than 95 percent, the hydrogenation degree of unsaturated bonds of aromatic hydrocarbon is less than 10 percent, and the residual quantity of the catalyst is less than 30 ppm; the catalyst is homogeneous hydrogenation catalyst, preferably titanocene dichloride and n-butyl lithium.

The functionalized SEBS is used as an interface compatibilizer.

The silicone/amino functionalized SEBS provided by the invention has the following advantages:

the preparation method is simple, the raw materials are easy to obtain, and the polarity degree of the prepared silica/amino functionalized SEBS is controllable; the molecular side chain contains controllable amount of silica/amido, and has controllable hydrophilicity; when the silica/amino functionalized SEBS is used as the interface compatilizer, the impact resistance of the composite material can be greatly improved, and the toughness of the composite material is obviously improved.

Drawings

FIG. 1 is a microscopic topography (SEM) of different compatibilized blends provided by the present invention; wherein (a) is a compatibilizer in comparative example 1, (b) is a compatibilizer in example 5, and (c) is a compatibilizer in example 2.

Detailed Description

The present invention will be described in further detail with reference to examples, which should not be construed as limiting the invention thereto.

The characterization method comprises the following steps:

1. microstructure and nitrogen content of the product¹H NMR，¹³C NMR, and the molecular weight of the polymer and its distribution by GPC.

2. Testing the surface contact angle of the obtained modified product by using a DSA-100 type contact angle tester, dripping distilled water drops with the diameter of about 2mm and the volume of about 3-5 mu L by using a sample injector during measurement, wherein the measurement time is not more than 1 minute, testing is carried out for 5 times, the interval of 2 seconds is kept for each time, and the average value of 5 times is taken as the contact angle of the material;

3. adopting an INSTRON 5567 type universal material testing machine to test the tensile strength of the test sample according to ASTM D-638-08, wherein the tensile speed is 50 mm/min;

4. the notch impact strength of the test piece is tested according to ASTM D256-06 by adopting a ZBC-4B pendulum impact tester of Shenzhen Xinsi metering technology Limited company.