阅读说明：本技术 一种铱催化脱氢偶联合成聚硅醚 (Synthesis of polysilicone by iridium catalytic dehydrogenation coupling ) 是由 周永贵 翟小勇 时磊 孙蕾 于 2018-06-01 设计创作，主要内容包括：本发明公开一种合成聚硅醚的方法,以铱的金属前体和双膦配体的配合物为催化剂,催化含有羟基硅烷的AB型单体脱氢偶联聚合制备所述聚硅醚；所述铱的金属前体、双膦配体、含有羟基硅烷的AB型单体的摩尔比为：0.005～0.025:0.01～0.05:1。本发明反应活性高,聚硅醚的数均分子量最高可达到9.27×104；催化剂制备方便,反应操作简便实用,反应条件温和；聚硅醚含有多样的骨架,且耐高温性能良好；合成方法操作简便实用易行,收率高,后处理简单,环境友好,催化剂商业可得,反应条件温和,具有潜在的实际应用价值。(The invention discloses a method for synthesizing polysilicether, which takes a complex of an iridium metal precursor and a diphosphine ligand as a catalyst to catalyze the dehydrogenation coupling polymerization of AB type monomers containing hydroxysilane to prepare the polysilicether; the molar ratio of the iridium metal precursor to the diphosphine ligand to the AB type monomer containing the hydroxyl silane is as follows: 0.005-0.025: 0.01-0.05: 1. The invention has high reaction activity, and the maximum number average molecular weight of the polysiloxane can reach 9.27 multiplied by 104; the catalyst is convenient to prepare, the reaction operation is simple, convenient and practical, and the reaction condition is mild; the polysilicone contains various frameworks and has good high temperature resistance; the synthesis method has the advantages of simple, practical and feasible operation, high yield, simple post-treatment, environmental protection, commercial availability of the catalyst, mild reaction conditions and potential practical application value.)

1.A method of synthesizing a polysiloxane, characterized by: the complex of iridium metal precursor and diphosphine ligand is used as a catalyst to catalyze the AB type monomer containing hydroxysilane to perform dehydrogenation coupling polymerization to prepare the polysiloxane; the molar ratio of the iridium metal precursor to the diphosphine ligand to the AB type monomer containing the hydroxyl silane is as follows: 0.005-0.025: 0.01-0.05: 1;

In the formula, R is C _7-11 alkyl or aryl, and the aryl comprises alkoxy substituted aryl and alkyl substituted aryl.

2. The method of claim 1, wherein: the method comprises two steps:

(1) Preparation of the catalyst

Under the protection of nitrogen, adding an iridium metal precursor and a diphosphine ligand into an organic solvent a, and reacting to obtain a catalyst solution or removing the solvent under reduced pressure to obtain a solid catalyst;

(2) dehydrocoupling polymerization

And under the protection of nitrogen, adding an AB type monomer containing hydroxysilane and an organic solvent b into the catalyst solution or the solid catalyst, and reacting to obtain a product of dehydrogenation coupling polymerization.

3. The method of claim 3, wherein: the organic solvent a used in the preparation of the catalyst is at least one selected from toluene, dichloromethane and tetrahydrofuran; the organic solvent b used in the dehydrogenation coupling polymerization is at least one selected from toluene, 1, 4-dioxane, benzene, dichloromethane and tetrahydrofuran or is solvent-free.

4. A method according to any one of claims 1-3, characterized by: the metal precursor of the iridium is a 1, 5-cyclooctadiene iridium chloride dimer.

5. the method of any one of claims 1-4, wherein: the diphosphine ligand is selected from DPPE, DPPP, DPPB, DPPF, DCPE or (R) -MeO-Biphep.

6. A method as claimed in claim 3, characterized by: and (3) carrying out dehydrogenation coupling polymerization reaction in the step (2), wherein the reaction temperature is 40-160 ℃, and the concentration of the AB type monomer containing hydroxysilane in the solvent (B) is 0.1-0.5 mmol/mL or no solvent is used in the reaction system.

Technical Field

The invention relates to a method for synthesizing a polysiloxane with good thermal stability by using iridium homogeneous system catalysis, and the synthesized polysiloxane has different frameworks, high number average molecular weight and low glass transition temperature, and belongs to the technical field of silicon-containing polymer synthesis.

Background

because the crusta contains abundant silicon and oxygen, the polymer material containing silicon and oxygen has the advantage of inexhaustibility. The polymer having a siloxane bond includes polysiloxane, silicone, and silicone. Because the main chain contains silicon-oxygen bonds, the properties of the polymers are similar, including thermal stability, gas permeability, biocompatibility, low glass transition temperature and the like. Materials based on these polymers have been widely used in the fields of high temperature resistant elastomers, conductive materials, chiral column fillers, and the like. Because the Si-O-C structure on the main chain is hydrolysable, the polysiloxane is a degradable material with great potential. In addition, the properties of the silicone, including thermal stability, degradability and thermomechanical properties, can also be adjusted by changing the structure of the monomer. (reference is made to (a) Li, Y.; Kawakami Y. Des Monomers Polym.2000,3,399.(b) Shea, K.J.; Loy, D.A.; Webster, O.J.Am.Chem.Soc.1992,114,6700.(C) Liu, Y.; Imae, I.; Makishima, A.; Kawakami, Y.Sci.Technol.Adv.Mat.2003, 4,27. (d) Lauter, U.; Kantor, S.W.; Schmidt-Rohr, K.; MacKnight, W.J.Macromolecules 1999,32,3426.(e) Nagaoka, K.; Naruse, H.; Shinohara I., Warno.J.Machar, W.J.Macromotes 1999,32,3426. S.J.; Ledys L.S.7, W.J.S.S.J.; pee E.S.S.S.7. J.S.S.S.J.;. Mic.S. K.; Ledys, K.S.7, K.; E.S.S. K. A. 7, 32, K. A.. In the past, the process for obtaining the polysilicone is mainly a polycondensation process, such as the polycondensation of alcohol, alkoxysilane or aminosilane with chlorosilane, but also hydrogen chloride, alcohol or amine and other small molecules are released, and the atom economy is low (reference two: (a) Dunnavant, W.R.; Markle, R.A.; Sinclair, R.G.; Stickney, P.B.; Curry, J.E.; Byrd, J.D.macromolecules 1968,1,249, (b) Dunnavant, W.R.; Markle, R.A.; Stickney, P.B.; Curry, J.E.; Byrd, J.J.Polym.Sci.Part.A 7, 1965, Drake, K.; Millak, J.E.; J.S.7, J.7, 1965, C.; CheroIk., Mikly, J.J.E.E.E.; J.J.S.7, J.S.7, J.D.D.D.D.D.D.C.; C. 31, Lerke J.S.S.7, J.J.S.S.22, J.J.S.S.S.S.22, J.J.J.D.D.D.D.D.S.S.A.; Lerke C.; E.S.S.7, J.J.S.J.S.J.7, J.J.J.7, Mitsu E.7, J.A.J.J.A.A.22, J.A.A.22, J.A. 25, J.A.7. Another more atom-economical approach to the synthesis of polysiloxanes by polyaddition of epoxy and chlorosilanes (ref.three: Nishikubo, t.; Kameyama, a.; Kimura, y.; Fukuyo, k. macromolecules 1995,28, 4361.). The hydrosilation of carbonyl groups is an important method for the synthesis of silyl ethers, however, until 2001, the hydrosilation synthesis of polysiloxanes by means of a ruthenium catalyst was not reported by Weber, which achieved the hydrosilation polymerization of a series of aldehydes or ketones to obtain the polysiloxanes (reference four: (a) Mabry, j.m.; Runyon, m.k.; Weber, w.p. macromolecules 2001,34,7264.(b) Mabry, j.m.; Paulasaari, j.k.; Weber, w.p. polymer 2000,41, 4423.). Dehydrogenation coupling is a simple, direct and atom-economical synthesis method and is widely applied to synthesis of the polysilicone. However, the early work was based on the dehydrogenation coupling polymerization of AA-type bis-silane monomers and BB-type bis-hydroxyl monomers, both monomers were added in equimolar amounts, which is cumbersome to operate, and the molecular weight of the resulting polysilicones is relatively low. For example, around 2000, Kawakami developed a catalytic system based on transition metals such as palladium, platinum, rhodium, etc., to achieve cross-dehydrocoupling polymerization of glycols or water with silanes (six (a) Li, Y.; Kawakami Y.macromolecules 1999,32,3540.(b) Kawakita, T.; Oh, H. -S.; Moon, J. -Y.; Liu Y.; Imae, I.; Kawakami.Y.Poly int.2001,50,1346. (c) Li, Y.; Kawakami Y.macromolecules 1999,32,6871.(d) Oishi, M.; Moon.J.; Janvikul, W.; Kawaukmi.Y.Poly. int. 50,135, Li, Y.; Semiwa, M.J.; Semikamikawa.52. Y.; Kawakamikamikam.M.M.2001, Y.; Kawakamikamikamikla Y.; M.S.S.S.S.S.; Oh.; La. S. H.; e). Recently, the Hartwig group has achieved cesium hydroxide catalyzed AB-type monomer dehydrogenation coupled polymerization, the monomers used in the polymerization are derived from biomass, and the polymerization products can also be degraded under acidic conditions. However, the molecular weight of the synthesized silicone is low, and the skeleton of the silicone is single and only chain (seven references: Cheng, C.; Watts, A.; Hillmyer, M.A.; Hartwig, J.F.Angew.Chem.int.Ed.2016,55,11872.). In consideration of the potential application value of the polysiloxane in high temperature resistant and degradable materials, it is still very significant to develop an efficient catalytic system to realize the synthesis of the polysiloxane with various frameworks.

Disclosure of Invention

The invention aims to provide a method for synthesizing polysilicone, which takes diphosphine P-P complex of iridium as a catalyst to realize dehydrogenation coupling polymerization of a series of AB type monomers containing hydroxysilane, and adopts the following technical scheme: the catalyst is a complex of iridium metal precursor and diphosphine ligand, and the molar ratio of the iridium metal precursor to the diphosphine ligand to a substrate is as follows: 0.005-0.025: 0.01-0.05: 1;

In the formula: r is C7-C11 alkyl or aryl, and the aryl comprises alkoxy substituted aryl and alkyl substituted aryl;

Another purpose is to provide a method for synthesizing the polysilicone, which is prepared by the dehydrogenation coupling polymerization reaction of AB type monomer containing hydroxyl silane, wherein the catalyst is a complex of iridium metal precursor and diphosphine ligand, and the molar ratio of the iridium metal precursor to the diphosphine ligand to the substrate is as follows: 0.005-0.025: 0.01-0.05: 1;

In the formula: r is C7-C11 alkyl or aryl, and the aryl comprises alkoxy substituted aryl and alkyl substituted aryl;

As a preferred technical solution, the method comprises two stages: (1) preparing a catalyst: adding an iridium metal precursor and a diphosphine ligand into an organic solvent a, and reacting (the reaction condition is preferably stirring for ten minutes at room temperature) to obtain a catalyst or removing the solvent under reduced pressure to obtain a solid catalyst; (2) dehydrogenation coupling polymerization: and under the protection of nitrogen, adding the substrate and the organic solvent b into the catalyst to react to obtain the polysiloxane. Removing the solvent under reduced pressure, adding 2 ml tetrahydrofuran to dissolve the product, dripping 15 ml cold methanol to separate out the product, removing the upper layer solvent, and pumping to obtain the polymerization product.

Preferably, the organic solvent a used in the preparation of the catalyst is selected from at least one of toluene, dichloromethane and tetrahydrofuran; more preferably dichloromethane. The organic solvent b used in the dehydrogenation coupling polymerization is at least one selected from toluene, 1, 4-dioxane, benzene, dichloromethane and tetrahydrofuran or no solvent; more preferably no solvent.

Preferably, the iridium metal precursor is selected from 1, 5-cyclooctadiene iridium chloride dimer.

Preferably, the ligand is selected from DPPE (CAS number: 1663-45-2) or DPPP (CAS number: 6737-42-4) or DPPB (CAS number: 7688-25-7) or DPPF (CAS number: 12150-46-8) or DCPE (CAS number: 23743-26-2) or (R) -MeO-Biphep (CAS number: 133545-16-1), more preferably bisphosphine ligand DPPP (CAS number: 6737-42-4).

Preferably, the reaction temperature is 40-160 ℃, more preferably 80-120 ℃, and the concentration of the AB type monomer in the solvent (B) is 0.1-0.5 mmol/mL or no solvent is used in the reaction system.

The invention has the beneficial effects

1. The reaction activity is high, and the number average molecular weight of the polysiloxane can reach 9.27 multiplied by 10 ⁴ to the maximum;

2. The catalyst is convenient to prepare, the reaction operation is simple, convenient and practical, and the reaction condition is mild;

3. the polysilicone contains various frameworks and has good high temperature resistance;

4. the synthesis method has the advantages of simple, practical and feasible operation, high yield, simple post-treatment, environmental protection, commercial availability of the catalyst, mild reaction conditions and potential practical application value.

Drawings

FIG. 1 shows the decomposition behavior of the polysiloxane 2e in methanol solution.

Detailed Description

The present invention will be described in more detail by way of examples, but the present invention is not limited to the following examples.

Both the metal precursors of iridium and the bisphosphine ligands are commercially available and do not require any treatment.

Monomers 1a-e can be synthesized by a two-step one-pot process, the first step being a hydrosilylation reaction catalyzed by Karstedt's catalyst, and the second step being a reduction of the hydrosilation product of the first step by lithium aluminum hydride to yield the monomers.