阅读说明：本技术 一种离子型铱配合物催化脱氢偶联合成部分可再生聚硅醚的方法 (Method for synthesizing partially renewable polysiloxanes by catalytic dehydrogenation coupling of ionic iridium complex ) 是由 周永贵 翟小勇 孙蕾 于 2019-04-16 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,离子型铱配合物为催化剂,实现不同类型单体脱氢偶联聚合,所述离子型铱配合物、含有羟基硅烷的单体的摩尔比为：0.005～0.020:1。本发明反应活性高,聚硅醚的数均分子量最高可达到4.38×10<Sup>4</Sup>；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；合成的聚硅醚部分来源于生物质,且可降解,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 polysilicone, which takes an ionic iridium complex as a catalyst to realize dehydrogenation coupling polymerization of different types of monomers, wherein the ionic iridium complex and a monomer containing hydroxysilane have the following molar ratio: 0.005-0.020: 1. The invention has high reaction activity, and the maximum number average molecular weight of the polysiloxane can reach 4.38 multiplied by 10 4 (ii) a 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 synthesized polysiloxane part is derived from biomass, and is degradable, the catalyst is commercially available, the reaction condition is mild, and the method has potential practical application value.)

1.A method of synthesizing a polysiloxane, characterized by: the ionic iridium complex is used as a catalyst,

the catalyst monomer (I) is dehydrogenated, coupled and polymerized to prepare the polysiloxane,

or preparing the polysilicone by dehydrogenating, coupling and polymerizing catalyst monomers (II) and (III);

the molar ratio of the ionic iridium complex to the monomer (I) is as follows: 0.005-0.020: 1; the molar ratio of the ionic iridium complex to the monomer (II) is 0.005-0.020: 1; the molar ratio of the monomer (II) to the monomer (III) is 1:1, and the specific reaction formula is as follows:

in the formula: r is C_7-11The aryl group includes alkoxy-substituted aryl groups and alkyl-substituted aryl groups; r' is C_4-10Alkyl groups of (a);

reaction temperature: 40-120 ℃; the reaction time is 12-48 h.

2. The method of claim 1, wherein the reaction temperature is 60 to 100 ℃.

3. The method of claim 1, wherein: the method comprises the following steps:

under the protection of nitrogen, adding a monomer (I) into the catalyst solution or the catalyst, and keeping the temperature at 40-120 ℃; the reaction time is 12-48h, and the polysiloxane is obtained;

or under the protection of nitrogen, adding monomers (II) and (III) into the catalyst solution or the catalyst, and keeping the temperature at 40-120 ℃; the reaction time is 12-48h, and the polysiloxane is obtained;

the catalyst solution is formed by dissolving the catalyst in an organic solvent.

4. The method according to claim 3, wherein the organic solvent is at least one of toluene, 1, 4-dioxane, benzene, acetonitrile, tetrahydrofuran.

5. The method of any one of claims 1-4, wherein: the ionic iridium complex is formed by CpIrCl₃Reacting with 6,6 '-dihydroxy-2, 2' -bipyridine under alkaline condition.

6. A method as claimed in claim 3, characterized by: the concentration of the monomer (I) in the catalyst solution is 0.1-1.0 mmol/mL, or the concentration of the monomer (II) or (III) in the catalyst solution is 0.1-1.0 mmol/mL respectively.

Technical Field

The invention belongs to the technical field of synthesis of silicon-containing polymers, and particularly relates to a method for synthesizing a polysiloxane with good thermal stability by using ionic iridium complex as a catalyst.

Background

Due to the gradual decrease of fossil resources, non-renewable and non-degradable synthetic polymer materials produced from fossil resources pose a serious threat to the ecosystem (reference one (a) van der Ploeg, f.j.econ. lit.2011,49, 366-. Although many groups have studied polymer materials based on renewable resources, the total amount of polymer materials synthesized from non-renewable fossil fuel resources is far greater than materials derived from renewable biomass. The main reasons are mainly the high cost and poor performance of renewable polymer materials (reference two: (a) Beach, e.s.; Cui, z.; anastatas, p.t. energy environ. sci.2009,2, 1038-. Currently, some renewable feedstocks have been applied to the synthesis of biopolymers, bio-resins and various value-added chemicals. For example, lactic acid, triglyceride fatty acids, 5-hydroxymethylfurfural or a derivative thereof, vanillin, and the like. Several polymers based on these raw materials have been developed to date, including poly (lactic acid), poly vanillin, poly (hydroxyalkanoate) and the like (reference three (a) Firdaus, M.; Meier, M.A.R.Europ.Polym.J.2013,49, 156-. In 2004, the U.S. department of energy (DOE) proposed the concept of "biomass-derived top-grade value-added chemicals" specifying a clear direction for the development of renewable polymeric materials (four references: Werpy, T.; Petersen, G.; Aden, A.; Bozell, J.; Holladay, J.; White, J.; Manheim, A.; Eliot, D.; Lasure, L.; Jones, S.DTIC document.2004.).

Among these renewable polymers, the polysiloxanes are a class of materials with many unique properties, including thermal stability, gas permeability, biocompatibility, degradability, and low glass transition temperature, among others. Materials based on these polymers have been widely used in the fields of high temperature resistant elastomers, conductive materials, chiral column fillers, etc. (fifth reference: (a) Li, y.; Kawakami y.desmonomers 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.mater.2003,4, 27.(d) Lauter, u.; Kantor, s.w.; Schmidt-Rohr, k.; MacKnight, w.j.macromoules 1999,32, 26. nagaa, k.34ruson, water, sho r.32, r.k.; r, r.t. lei, r.t.;. pee r, r.t.; r. t. r. ne, r.t. r. ne, r. t. ne, r. k.;. r. e.r. r. t. r., t. k.;. r. e. 35. r. g. k.;. r. lei. r., pee. r., t., r., t., r.. Dehydrocoupling polymerization is one of the important methods for synthesizing polysiloxanes. The most commonly used monomers for dehydrocoupling polymerization are monomers of the AA type (dihydroxy compounds) and monomers of the BB type (silanes). AA type monomers include mainly diols, diphenols, water and disilanols (ref. six (a) Li, Y.; Kawakami, Y. Macromolecules 1999,32,8768-8773.(b) Li, Y.; Kawakami, Y. Macromolecules 1999,32, 6871-6873.(c) Li, Y.; Kawakami, Y. Macromolecules 1999,32,3540-3542.(d) Cella, J.; Russbindajn, S. Macromolecules 2008,41, 6965-6971.). However, most of the polysiloxanes are derived from non-renewable raw materials, which hinders their sustainable development. After analyzing the functional group structures of the first 10 chemicals from biomass, we found that more than half of these compounds could be converted to diols including succinic, 2-hydroxymethyl-5-furfural and fructonic acids in high yield, which could be converted to 1, 4-butanediol, 2, 5-furandimethanol, 1, 4-pentanediol, etc., respectively (ref.seven: Bozell, j.j.; Petersen, g.r.green chem.2010,12, 539-. Based on these considerations, we envision the application of these biomass-derived diols to the synthesis of polysilicones.

To our knowledge, monomers derived from fructonic acids have not been applied to the synthesis of polysiloxanes by dehydrocoupling. As an efficient and highly atom-efficient method for constructing Si-O bonds, dehydrocoupling reactions have been accomplished with transition metal-based complexes, such as palladium, platinum, rhodium, and manganese (eight (a) Li, Y.; Kawakami Y.macromolecules 1999,32,3540. (b) Kawakita, T.; Oh., H. -S.; Moon, J. -Y.; Liu, Y.; Imae, I.; Kawakami.Y.Polyint.2001,50,1346. (c) Li, Y.; Kawakami Y.macromolecules 1999,32,6871.(d) Oishi, M.; Moon.J.; Janvikul, W.; Kawakamika. Y.Polyint.2001.3532.; 50,135. Li, Y.; Semiwa, Y.; Semiwa.2000. Y.; Kawakamikamo, Y.; Y.S.33. Mo.; Mi M.33. 2000. J.; Kawakamikayaki.S.; M.S. S.S.; M.S. S. H.; and S. E).

Disclosure of Invention

The invention aims to provide a method for synthesizing polysilicone, which takes an ionic iridium complex as a catalyst to realize dehydrogenation coupling polymerization of different types of monomers, and adopts the following technical scheme: the method is used for preparing the polysilicone by catalyzing dehydrogenation coupling polymerization reaction of monomers (AB type or AA and BB type) containing hydroxyl silane, wherein the catalyst is the molar ratio of the ionic iridium complex to a substrate (when the monomers (II) and (III) are used, the molar ratio is the ratio of the catalyst to the monomer II, and the molar ratio of the monomer (II) to the monomer (III) is 1: 1): 0.005-0.020: 1; the structural formula of the AB type monomer containing the hydroxyl silane is (I), the structural formulas of the AA type monomer and the BB type monomer are (II) and (III), and the specific reaction formulas are as follows:

in the formula: r is C_7-11The aryl group of (a) is a substituted or unsubstituted aryl group, and the substituted aryl group includes alkoxy-substituted aryl groups and alkyl-substituted aryl groups; r' is C_4-10Alkyl groups of (a);

reaction temperature: 40-120 ℃; the reaction time is 12-48 h.

Preferably, the reaction temperature is 60-100 ℃.

As a preferred technical solution, the method includes two steps:

the method comprises the following steps: adding a substrate (monomer (I) or monomers (II) and (III)) into the catalyst to react under the protection of nitrogen to obtain the polysilicone, removing the solvent under reduced pressure, adding 2 ml of dichloromethane to dissolve the product, dropwise adding 15 ml of cold methanol to separate out the product, removing the upper-layer solvent, and draining to obtain the polymerization product.

The second method comprises the following steps: (1) preparing a catalyst: adding the ionic iridium complex catalyst into an organic solvent, and stirring for 2min at room temperature to obtain a catalyst solution; (2) adding a substrate (monomer (I) or monomers (II) and (III)) into the catalyst solution to react under the protection of nitrogen to obtain the polysilicone, removing the solvent under reduced pressure, adding 2 ml of dichloromethane to dissolve the product, dropwise adding 15 ml of cold methanol to separate out the product, removing the upper-layer solvent, and draining to obtain a polymerization product

Preferably, the organic solvent used in the preparation of the catalyst solution is selected from at least one of toluene, benzene, acetonitrile, tetrahydrofuran, preferably acetonitrile.

Preferably, the ionic iridium complex is formed by CpIrCl₃Reacting with 6,6 '-dihydroxy-2, 2' -bipyridine under alkaline condition.

Preferably, the concentration of the monomer (I) in the catalyst solution is 0.1 to 1.0mmol/mL, or the concentrations of the monomers (II) and (III) in the catalyst solution are respectively 0.1 to 1.0 mmol/mL.

The polysiloxanes synthesized by the present invention are derived from different types of monomers. There are three biomass-derived diol compounds used in the synthesis of polysiloxanes. Therefore, the synthesized polysilicone is partially reproducible and has the characteristics of different frameworks, high number average molecular weight, low glass transition temperature and the like

Advantageous effects

1. High reaction activity, and the maximum number-average molecular weight of the polysiloxane can reach 4.38 multiplied by 10⁴；

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 synthesized polysiloxane part is derived from biomass, and is degradable, the catalyst is commercially available, the reaction condition is mild, and the method has potential practical application value.

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.

Ionic iridium complexes were synthesized by procedures described in the literature (references: Fujita, K.; Kawahara, R.; Aikawa, T.; Yamaguchi, R. Angew. chem. int. Ed.2015,54,9057-₂(CAS: 12354-84-6) and 6,6 '-dihydroxy-2, 2' -bipyridine (CAS:103505-54-0) were both commercially available and did not require any treatment.

The monomer 1a-e reference was 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 lithium aluminum hydride to reduce the hydrosilation product of the first step to yield the monomer. The monomeric 1f reference (reference: Koha, P. -F.; Loh, T. -P. Green chem.2015,17, 3746-. Monomers 1g-h and 3 are both commercially available (purchased from Intoka).

Wherein 1g of the monomer is subjected to azeotropic dehydration by using toluene and ethanol, and the treatment method comprises the following steps: putting 1g of 5 g of monomer into a reaction bottle, adding 5mL of anhydrous ethanol and 20mL of anhydrous toluene, connecting a fractionating column to the reaction bottle, raising the temperature, removing azeotropic fraction by fractional distillation under normal pressure, removing residual solvent by reduced pressure and distilling to obtain 1g of monomer.

The monomer is purified by recrystallization in ethyl acetate for 1h, and the processing method comprises the following steps: putting 10 g of monomer into a reaction bottle for 1h, adding 50mL of ethyl acetate, heating to dissolve the monomer (if the monomer cannot be completely dissolved, adding a proper amount of ethyl acetate), cooling to room temperature, crystallizing and separating out the monomer, performing suction filtration, and removing the solvent under reduced pressure to obtain the monomer for 1 h.

Monomer 3 needs to be subjected to a distillation purification treatment in calcium hydride: 5 g of the monomer 3 was put into a reaction flask, and 500mg of calcium hydride was added thereto, and the mixture was stirred overnight at room temperature and distilled under reduced pressure to obtain a monomer 3.