CN114478839B - Hydrogenated nitrile latex prepared by self-hydrogen production hydrogenation method - Google Patents

Hydrogenated nitrile latex prepared by self-hydrogen production hydrogenation method Download PDF

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CN114478839B
CN114478839B CN202210134627.0A CN202210134627A CN114478839B CN 114478839 B CN114478839 B CN 114478839B CN 202210134627 A CN202210134627 A CN 202210134627A CN 114478839 B CN114478839 B CN 114478839B
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catalyst
hydrogenation
hydrogen
hydrogenated nitrile
nitrile latex
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CN114478839A (en
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岳冬梅
杨志伟
潘超仑
张立群
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Beijing University of Chemical Technology
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Abstract

The invention relates to the field of hydrogenation of butyronitrile latex, in particular to a method for preparing hydrogenated butyronitrile latex by a self-hydrogen production hydrogenation method. The preparation method of the hydrogenated nitrile-butadiene latex provided by the invention realizes the catalytic hydrogenation of nitrile-butadiene rubber by the self-hydrogen generation or catalytic transfer hydrogenation reaction of a hydrogen donor in a system under the action of a catalyst; the catalyst is one or more of a Schrock type catalyst, a Grubbs type catalyst or a Hoveyda-Grubbs type catalyst; the hydrogen donor is one or more of isopropanol, formic acid, a composition of formate and ethylenediamine, sodium borohydride or a nitrogen borohydride compound. The butyronitrile latex hydrogenation method provided by the invention realizes the aim of catalyzing and hydrogenating butyronitrile latex without additional hydrogen under the action of a commercial catalyst, greatly reduces the hydrogenation cost of butyronitrile latex, has higher hydrogen evolution efficiency of a hydrogen donor and less catalyst consumption, is more suitable for industrial large-scale production, and accords with the concept of environmental protection.

Description

Hydrogenated nitrile latex prepared by self-hydrogen production hydrogenation method
Technical Field
The invention relates to the field of hydrogenation of butyronitrile latex, in particular to a method for preparing hydrogenated butyronitrile latex by a self-hydrogen production hydrogenation method.
Background
Nitrile-butadiene rubber (NBR) is a copolymer formed by polymerizing butadiene and acrylonitrile monomers through low-temperature emulsion, and has particularly good oil resistance, higher wear resistance and strong binding power due to the cyano-group contained in the molecular structure. However, the butadiene-acrylonitrile rubber has poor weather resistance and heat resistance due to unsaturated bonds in the segment, and thus the industrial application is limited, and hydrogenated nitrile-butadiene rubber (HNBR) is produced accordingly.
The method for selectively hydrogenating the unsaturated double bond in the main chain of the nitrile rubber at the present stage mainly comprises the following steps: ethylene acrylonitrile copolymerization, solution hydrogenation, emulsion hydrogenation.
The ethylene acrylonitrile copolymerization method has the problems that the copolymerization is difficult due to the high reactivity ratio of two monomers, the method mechanism is free radical polymerization, and side reactions such as chain transfer, rearrangement and the like are easy to occur on products to influence the performance of the products, so that the industrial application of the method needs to be researched.
The solution hydrogenation method is the most industrially applied method at present, and is mainly divided into a homogeneous catalytic solution hydrogenation method and a heterogeneous catalytic solution hydrogenation method. The method needs more organic solvents in the hydrogenation process, needs high-temperature and high-pressure reaction conditions, has certain pollution to the environment and increases the production cost.
The emulsion hydrogenation method refers to the selective hydrogenation of unsaturated bonds on chain segments by the nitrile rubber in an emulsion state, and the product can be directly used for coatings, adhesives and the like. The emulsion hydrogenation method is mainly divided into a hydrogenation matrix method, a Wilkinson catalyst hydrogenation method and an oil-soluble catalyst hydrogenation method.
In the patent US4464515, tetrakis (triphenylphosphine) rhodium hydride is used as a hydrogenation catalyst, triphenylphosphine is used as a ligand to hydrogenate NBR emulsion, and HNBR with a hydrogenation degree of 99% is finally obtained, but the hydrogenation product has gel generation, which affects the subsequent application thereof.
In order to solve the problem, the patents US4464515 and US5208296 add organic or inorganic additives into the catalytic system, and successfully inhibit the generation of gel. In patent CN104428325A, CN111363094A, CN111479831A, hoveyda-Grubbs second generation is used as a hydrogenation catalyst, a series of auxiliaries are added into a system to improve the hydrogenation degree, and no gel is generated in the system.
Except that the hydrogenation parent method takes non-hydrogen substances as hydrogen supply, other methods all need additional hydrogen to carry out catalytic hydrogenation, the cost is improved to a certain extent, and the method also does not accord with the idea of green chemistry.
CN108993608A discloses a multifunctional catalyst and discloses a method for preparing HNBR by using xylene and ethanol as mixed solvents under the condition of no additional hydrogen and carrying out in-situ hydrogen production and selective hydrogenation reaction on nitrile rubber in situ under the action of the multifunctional catalyst. However, the hydrogen source and the catalyst selected by the method are only suitable for the solution hydrogenation method and are not suitable for the emulsion hydrogenation method; moreover, the multifunctional catalyst used in the method is a non-commercial product, so that the hydrogenation cost of the nitrile rubber is high; meanwhile, the mixed solvent of the method has low hydrogen evolution efficiency, and in order to obtain high hydrogenation degree, the catalyst (3.5 percent of the mass of the glue solution) and the organic solvent have large use amount, so that the aim of preparing the hydrogenated nitrile-butadiene rubber without additional hydrogen can be fulfilled, but the industrial large-scale production is difficult.
Disclosure of Invention
In order to solve the technical problems, the invention provides a preparation method of hydrogenated nitrile-butadiene latex without additional hydrogen, which is more suitable for industrial production.
The preparation method of the hydrogenated nitrile-butadiene latex provided by the invention comprises the following steps: under the action of a catalyst, the catalytic hydrogenation of the nitrile rubber is realized through the self-hydrogen generation or catalytic transfer hydrogenation reaction of a hydrogen donor in a system;
the catalyst is one or more of a Schrock type catalyst, a Grubbs type catalyst or a Hoveyda-Grubbs type catalyst;
the hydrogen donor is one or more of isopropanol, formic acid, a composition of formate and ethylenediamine, sodium borohydride or a nitrogen borohydride compound;
the structure of the nitrogen boron hydrogen compound is shown as a formula 1:
Figure BDA0003503974880000021
wherein R is 1 、R 2 、R 3 And R 4 Each independently selected from one of hydrogen, halogen, alkyl, cycloalkyl, alkenyl, alkynyl, aryl, alkoxy, alkenyloxy, alkynyloxy, aryloxy, alkoxycarbonyl, alkylamino, alkylthio, arylthio, alkylsulfinyl or metal group.
The butyronitrile latex hydrogenation method provided by the invention realizes the aim of catalyzing and hydrogenating butyronitrile latex without additional hydrogen under the action of a commercial catalyst, greatly reduces the hydrogenation cost of butyronitrile latex, has higher hydrogen evolution efficiency of a hydrogen donor and less catalyst consumption, is more suitable for industrial large-scale production, and accords with the concept of environmental protection.
Preferably, the hydrogen donor is dimethyl ammonia borane or ammonia borane; researches show that compared with other hydrogen donors, the dimethyl ammonia borane or the ammonia borane has the advantages of more stable physicochemical property, better water solubility and higher hydrogen content.
Further, the catalyst is preferably a Hoveyda Grubbs second-generation catalyst, which not only can be used for hydrogenation reaction to realize hydrogenation, but also can catalyze a hydrogen donor to produce hydrogen, thereby being more beneficial to improving the hydrogen evolution efficiency of the hydrogen donor and reducing the production cost.
Further, the mass ratio of the hydrogen donor to the catalyst is 1g: (1 mg-10 mg), preferably 1g: (1 mg-4 mg). Research shows that the hydrogen evolution efficiency and the hydrogenation degree can be obviously improved by reasonably controlling the proportional relation of the two.
The solid content of the butyronitrile latex is 5-45 wt%, and meanwhile, researches show that the hydrogenation reaction efficiency is increased and then reduced along with the increase of the concentration of the butyronitrile latex, so that the solid content of the butyronitrile latex is preferably 10-30 wt%. The acrylonitrile content in the acrylonitrile-butadiene latex is within the range of 10wt% -45 wt%.
Further, the mass ratio of the hydrogen donor to the butyronitrile latex is 1-200%; preferably, the dosage relationship between the hydrogen donor and the butyronitrile latex is 1-50%.
The dosage of the catalyst is not more than 5 percent of the mass of the butyronitrile latex.
Further, the conditions of the hydrogenation reaction are as follows: the temperature is between room temperature and 160 ℃, preferably between 60 and 130 ℃; the rotating speed is 50-1000 r/min, preferably 200-600 r/min; the reaction time is 1-24 h, preferably 6-14h.
The invention has the following beneficial effects:
the hydrogen donor selected by the invention can spontaneously generate hydrogen in a system or realize the emulsion method to prepare the hydrogenated butyronitrile latex under the condition of transfer hydrogenation; moreover, the hydrogen evolution efficiency of the selected hydrogen donor is high, and the high-efficiency selective hydrogenation can be carried out on the butyronitrile latex under the conditions of not introducing hydrogen and using a small amount of commercial catalyst to obtain a product with high hydrogenation degree.
The hydrogenation method provided by the invention has important application value in the field of preparation of hydrogenated nitrile-butadiene latex by an emulsion method. Compared with the existing butyronitrile latex hydrogenation method without additional hydrogen, the method of the invention has lower cost and is more beneficial to large-scale industrial production.
Drawings
FIG. 1 shows the hydrogenation effect of the hydrogenation process for nitrile latex described in example 1.
Detailed Description
The following examples are intended to illustrate the invention but are not intended to limit the scope of the invention.
Each of the components in the following examples is commercially available.
Example 1
4mg of Hoveyda-GrubbsII catalyst was added to 50g of nitrile latex (25% strength by weight), and 1g of dimethylaminoborane was added to the mixture;
after degassing, the temperature is raised to 90 ℃, and the reaction is carried out for 12 hours at the rotating speed of 300r/min;
after the reaction is finished, ethanol is used for flocculating and precipitating the gel;
the degree of hydrogenation of the resulting product was 98.5%, as shown in FIG. 1.
Example 2
4mg of Hoveyda-GrubbsII catalyst were added to 50g of nitrile latex (25% strength by weight), and 1g of aminoborane was added to the mixture;
after degassing, raising the temperature to 90 ℃, and reacting for 12 hours at the rotating speed of 300r/min;
after the reaction is finished, ethanol is used for flocculating and precipitating the gel;
the degree of hydrogenation of the product obtained was 78.0%.
The results show that: compared with example 1, the hydrogenation effect of the hydrogen donor ammonia borane is lower than that of dimethyl ammonia borane.
Example 3
3mg of Hoveyda-GrubbsII catalyst was added to 50g of nitrile latex (25 wt%), and 1g of dimethyl amino borane was added to the mixture;
after degassing, raising the temperature to 90 ℃, and reacting for 12 hours at the rotating speed of 300r/min;
after the reaction is finished, ethanol is used for flocculating and precipitating the gel;
the degree of hydrogenation of the product obtained was 87.9%.
Example 4
2mg of Hoveyda-GrubbsII catalyst was added to 50g of nitrile latex (25% strength by weight), and 1g of dimethylaminoborane was added to the mixture;
after degassing, raising the temperature to 90 ℃, and reacting for 12 hours at the rotating speed of 300r/min;
after the reaction is finished, ethanol is used for flocculating and precipitating the gel;
the degree of hydrogenation of the product obtained was 78.0%.
Example 5
1mg of Hoveyda-GrubbsII catalyst was added to 50g of nitrile latex (25 wt%), and 1g of dimethyl amino borane was added to the mixture;
after degassing, raising the temperature to 90 ℃, and reacting for 12 hours at the rotating speed of 300r/min;
after the reaction is finished, ethanol is used for flocculating and precipitating the gel;
the degree of hydrogenation of the product obtained was 60.6%.
The results show that: the catalysts of examples 3-5 were used in progressively lower amounts compared to example 1, with a corresponding decrease in the degree of hydrogenation.
Example 6
4mg of Hoveyda-GrubbsII catalyst was added to 50g of nitrile latex (25% strength by weight), and 1g of dimethylaminoborane was added to the mixture;
after degassing, raising the temperature to 80 ℃, and reacting for 12 hours at the rotating speed of 300r/min;
after the reaction is finished, ethanol is used for flocculating and precipitating the gel;
the degree of hydrogenation of the product obtained was 90.2%.
Example 7
4mg of Hoveyda-GrubbsII catalyst was added to 50g of nitrile latex (25% strength by weight), and 1g of dimethylaminoborane was added to the mixture;
after degassing, raising the temperature to 100 ℃, and reacting for 12 hours at the rotating speed of 300r/min;
after the reaction is finished, ethanol is used for flocculating and precipitating the gel;
the degree of hydrogenation of the product obtained was 96.3%.
Example 8
4mg of Hoveyda-GrubbsII catalyst was added to 50g of nitrile latex (25% strength by weight), and 1g of dimethylaminoborane was added to the mixture;
after degassing, the temperature is raised to 110 ℃, the reaction is carried out for 12 hours, and the rotating speed is 300r/min;
after the reaction is finished, ethanol is used for flocculating and precipitating the gel;
the degree of hydrogenation of the product obtained was 95.7%.
Example 9
4mg of Hoveyda-GrubbsII catalyst was added to 50g of nitrile latex (25% by weight), and 1g of dimethylaminoborane was added to the mixture;
after degassing, raising the temperature to 120 ℃, and reacting for 12 hours at the rotating speed of 300r/min;
after the reaction is finished, ethanol is used for flocculating and precipitating the gel;
the degree of hydrogenation of the product obtained was 90.7%.
Example 10
4mg of Hoveyda-GrubbsII catalyst was added to 50g of nitrile latex (25% by weight), and 1g of dimethylaminoborane was added to the mixture;
after degassing, the temperature is raised to 130 ℃, the reaction is carried out for 12 hours, and the rotating speed is 300r/min;
after the reaction is finished, ethanol is used for flocculating and precipitating the gel;
the degree of hydrogenation of the product obtained was 89.6%.
The results show that: compared with the example 1, the reaction temperature and the hydrogenation degree of the examples 6 to 10 are different; it is shown that the degree of hydrogenation increases with an increase in the reaction temperature, but decreases with an increase in the temperature when the reaction temperature exceeds 100 ℃.
Comparative example 1
This comparative example differs from example 1 in that: no hydrogen donor is added; the method comprises the following specific steps:
4mg of catalyst was added to 50g of nitrile latex (25% strength by weight);
and (3) after degassing, raising the temperature to 90 ℃, reacting for 12 hours, flocculating and precipitating gel by using ethanol after the reaction is finished, wherein the hydrogenation degree of the obtained product is 0%.
Comparative example 2
This comparative example provides the method described in example 9 of CN108993608a, as follows:
the NBR is dissolved in a xylene ethanol mixed solvent (the volume ratio of ethanol to xylene is 2 to 100) to prepare NBR glue solution with the mass fraction of 10 percent. 50g of NBR glue solution is put into a 100ml reaction kettle, ru-PDA/GO multifunctional catalyst with glue solution mass fraction of 3.5 percent is added, the mixture reacts for 6 hours at 50 ℃ under the condition of 300r/min of rotating speed, and the hydrogenation degree is 96.7 percent.
The result shows that the hydrogenation degree obtained by the method is higher, is equivalent to that of the embodiment 3 of the invention and is lower than that of the embodiment 2; but because of low hydrogen evolution efficiency and large consumption of catalyst and organic solvent, the method is not suitable for industrial large-scale production. Meanwhile, the method is a solution hydrogenation method, and the principle is different from that of the emulsion hydrogenation method.
Although the invention has been described in detail hereinabove with respect to a general description and specific embodiments thereof, it will be apparent to those skilled in the art that modifications or improvements may be made thereto based on the invention. Accordingly, it is intended that all such modifications and alterations be included within the scope of this invention as defined in the appended claims.

Claims (11)

1. A preparation method of hydrogenated nitrile latex is characterized in that under the action of a catalyst, hydrogen donor generates self-hydrogen production or catalytic transfer hydrogenation reaction in a nitrile latex system to realize the catalytic hydrogenation of nitrile rubber; the mass ratio of the hydrogen donor to the catalyst is 1g: (1 mg-10 mg);
the catalyst is a Hoveyda-Grubbs type catalyst;
the hydrogen donor is dimethyl ammonia borane or ammonia borane;
the solid content of the butyronitrile latex is within the range of 5wt% -45 wt%;
the acrylonitrile content in the acrylonitrile-butadiene latex is within the range of 10wt% -45 wt%;
the mass ratio of the hydrogen donor to the butyronitrile latex is 1-200%.
2. The process for the preparation of hydrogenated nitrile latex according to claim 1, wherein the catalyst is a Hoveyda Grubbs' second generation catalyst.
3. The process for the preparation of a hydrogenated nitrile latex according to claim 2, wherein the mass ratio of the hydrogen donor to the catalyst is 1g: (1 mg-4 mg).
4. The process for the preparation of hydrogenated nitrile latex according to claim 1, wherein the mass ratio of said hydrogen donor to nitrile latex is between 1% and 50%.
5. The process for the preparation of hydrogenated nitrile latex according to claim 1, wherein the catalyst is used in an amount not exceeding 5% by mass of the nitrile latex.
6. The process for the preparation of hydrogenated nitrile latex according to claim 1, wherein the temperature of the self-hydrogen production or catalytic transfer hydrogenation reaction is between room temperature and 160 ℃.
7. The process for the preparation of hydrogenated nitrile latex according to claim 6, wherein the temperature of the self-hydrogen production or catalytic transfer hydrogenation reaction is between 60 and 130 ℃.
8. The process for preparing hydrogenated nitrile latex according to claim 6, wherein the rotation speed in the self-hydrogen production or catalytic transfer hydrogenation reaction is 50 to 1000r/min.
9. The process for the preparation of hydrogenated nitrile latex according to claim 8, wherein said rotation speed is comprised between 200 and 600r/min.
10. The method for preparing hydrogenated nitrile latex according to claim 6, wherein the reaction time in the self-hydrogen production or catalytic transfer hydrogenation reaction is 1-24 h.
11. The process for the preparation of hydrogenated nitrile latex according to claim 10, wherein said reaction time is comprised between 6 and 14h.
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* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5399632A (en) * 1992-09-30 1995-03-21 Exxon Research & Engineering Co. Hydrogenation process for unsaturated homo and copolymers
ATE293130T1 (en) * 1999-12-08 2005-04-15 Dow Global Technologies Inc METHOD FOR HYDROGENATION OF UNSATURATED POLYMERS
DE102004002576A1 (en) * 2004-01-17 2005-08-04 Bayer Ag Process for the hydrogenation of double bond-containing, unsaturated polymers
EP2158154A4 (en) * 2007-05-18 2012-06-13 Kanata Chemical Technologies Inc Method for the production of hydrogen from ammonia borane
CN101486775B (en) * 2009-02-27 2012-03-21 北京化工大学 Hydrogenation method for NBR Latex
KR101156407B1 (en) * 2010-07-27 2012-06-13 고려대학교 산학협력단 Catalyst for dehydrogenation of ammonia borane compound and method for generating hydrogen using the same
CN102827309B (en) * 2012-09-08 2014-04-16 北京化工大学 Hydrogenation method for organic catalyst normal-pressure catalytic butyronitrile rubber latex
CN110862467B (en) * 2019-09-25 2022-03-04 青岛科技大学 Selective hydrogenation method for conjugated diene rubber latex

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