Method for hydrogenation and catalyst separation of nitrile rubber by using ionic liquid
阅读说明：本技术 一种离子液体用于腈橡胶的加氢和催化剂分离的方法 (Method for hydrogenation and catalyst separation of nitrile rubber by using ionic liquid ) 是由 李跃辉 赵娇娇 邓理 陈娜娜 李洋 李晨 孙玉霞 于 2021-08-09 设计创作，主要内容包括：本发明涉及一种离子液体用于腈橡胶的加氢和催化剂分离的方法,该方法是指在浓度为5～25wt%的腈橡胶溶液中加入离子液体和贵金属催化剂,于氢气气氛下反应,反应结束后加入非极性溶剂,经搅拌、静置分相、分离,即分别得到贵金属催化剂和反应产物氢化腈橡胶。本发明不仅可以避免催化剂被聚合物包裹活性中心而失活,有利于保持加氢反应过程中催化剂的活性,而且反应后催化剂与产物易于分离,通过沉降分离离子液体实现催化剂的循环利用,解决了催化剂无法有效循环使用的问题,不仅能降低生产成本,还能提高产品性能,具有良好的工业应用前景。(The invention relates to a method for hydrogenation and catalyst separation of an ionic liquid for nitrile rubber, which comprises the steps of adding the ionic liquid and a noble metal catalyst into a nitrile rubber solution with the concentration of 5-25 wt%, reacting in a hydrogen atmosphere, adding a non-polar solvent after the reaction is finished, stirring, standing for phase separation, and separating to obtain the noble metal catalyst and a reaction product hydrogenated nitrile rubber respectively. The invention can not only avoid the inactivation of the catalyst caused by the active center being wrapped by the polymer, which is beneficial to keeping the activity of the catalyst in the hydrogenation reaction process, but also can easily separate the catalyst from the product after the reaction, realize the recycling of the catalyst by settling and separating the ionic liquid, solve the problem that the catalyst can not be effectively recycled, not only can reduce the production cost, but also can improve the product performance, and has good industrial application prospect.)
1. A method for hydrogenation and catalyst separation of nitrile rubber by using ionic liquid is characterized by comprising the following steps: the method comprises the steps of adding ionic liquid and a noble metal catalyst into a nitrile rubber solution with the concentration of 5-25 wt%, reacting in a hydrogen atmosphere, adding a nonpolar solvent after the reaction is finished, stirring, standing for phase splitting, and separating to obtain the noble metal catalyst and a reaction product, namely hydrogenated nitrile rubberGluing; the mass ratio of the organic solvent to the ionic liquid in the nitrile rubber solution is 1: 0.1 to 4; the mass ratio of the nonpolar solvent to the organic solvent is 0.1: 1-10: 1; the dosage of the noble metal catalyst is 1 multiplied by 10 of the mass of the nitrile rubber in the nitrile rubber solution-5 ~ 1×10-2And (4) doubling.
2. A process for the hydrogenation and catalyst separation of nitrile rubber according to claim 1, wherein: the nitrile rubber solution with the concentration of 5-25 wt% is formed by dissolving nitrile rubber in an organic solvent and uniformly dissolving the nitrile rubber by ultrasonic.
3. A process for the hydrogenation and catalyst separation of nitrile rubber according to claim 2, wherein: the nitrile rubber is nitrile rubber or valeronitrile rubber.
4. A process for the hydrogenation and catalyst separation of nitrile rubber according to claim 2, wherein: the organic solvent is one or more of toluene, xylene, chlorobenzene and butanone.
5. A process for the hydrogenation and catalyst separation of nitrile rubber according to claim 1, wherein: the ionic liquid is one or a mixture of imidazole, pyridine, quaternary ammonium, quaternary phosphonium, pyrrolidine and piperidine ionic liquids.
6. The process according to claim 5, wherein the ionic liquid is used for hydrogenation and catalyst separation of nitrile rubber: the cation of the ionic liquid refers to alkyl imidazole cation, alkyl pyridine cation, pyrrolidine cation, piperidine cation, quaternary ammonium salt cation, quaternary phosphonium salt cation and one of derivatives of the cations.
7. An ionic liquid as claimed in claim 5A process for the hydrogenation and catalyst separation of nitrile rubber characterized by: the anion of the ionic liquid is Cl-、HSO4 -、H2PO4 -、BF4 -、CF3Ac-、OTf -、TS-One kind of (1).
8. A process for the hydrogenation and catalyst separation of nitrile rubber according to claim 1, wherein: the noble metal component in the noble metal catalyst refers to one or more of rhodium, ruthenium, palladium, iridium and platinum.
9. A process for the hydrogenation and catalyst separation of nitrile rubber according to claim 1, wherein: the nonpolar solvent is one or more of cyclopentane, n-hexane, cyclohexane and n-heptane.
10. A process for the hydrogenation and catalyst separation of nitrile rubber according to claim 1, wherein: the reaction conditions are that the hydrogen pressure is 0.5-10 MPa, the temperature is 30-190 ℃, and the reaction time is 1-96 h.
Technical Field
The invention relates to the field of polymer hydrogenation modification, in particular to a method for hydrogenation and catalyst separation of nitrile rubber by using an ionic liquid.
Background
The rubber is an elastomer material with thermosetting property, most of the main polymer chains in the rubber contain carbon-carbon unsaturated double bonds, such as Nitrile Butadiene Rubber (NBR), Styrene Butadiene Rubber (SBR), polybutadiene rubber (EBR), Natural Rubber (NR) and the like, and the contained carbon-carbon unsaturated double bonds enable the rubber to have better elasticity and flexibility resistance, but have poorer heat resistance and aging resistance. The hydrogenation modification refers to the reduction of carbon-carbon unsaturated double bonds in the polymer into single bonds with stable chemical structures, so that the product has excellent mechanical properties, aging resistance and thermal oxygen stability, the service life of the product is prolonged, and the application field of the rubber material is expanded.
Hydrogenated nitrile rubber (HNBR) is usually highly saturated nitrile rubber prepared by selective hydrogenation of butadiene units in NBR, and compared with nitrile rubber, the hydrogenated nitrile rubber has high strength, tear resistance, wear resistance, aging resistance and thermal oxygen stability, retains the oil resistance of nitrile rubber, has certain chemical resistance and weather resistance, is very suitable for being used as a sealing element of oil-resistant rubber, can be used in harsh environments, and is widely used for sealing parts in the automobile industry, the petroleum industry and the aerospace industry, such as automobile fuel system parts, fuel hoses, engine oil hoses and the like.
The homogeneous catalytic hydrogenation system has the advantages of high hydrogenation activity and good selectivity because the catalyst and the Rubber solution are in the same phase, and is widely applied to the hydrogenation modification of the nitrile Rubber, and the rhodium complex catalyst can completely hydrogenate (NBR) (HD = 100%) (Rubber Chemistry and Technology, 2008, 81(2): 227 and 243.) under the appropriate reaction condition. However, the rhodium catalyst used at present is sensitive to air and expensive, and the catalyst is difficult to separate and recover, and a large amount of metal rhodium remains in the glue solution after the reaction, so that the cost of hydrogenated products is increased, and the processability and the aging resistance of the products are influenced. Therefore, the recovery of the catalyst after the reaction can not only reduce the production cost, but also increase the performance of the product, thereby having important significance. Patent US 6207795 discloses a method for recovering catalyst by acid-base precipitation, patent US 6646059 discloses a method for recovering catalyst by ion exchange resin adsorption, both methods add precipitator or adsorbent in the system after reaction to recover metal, the recovered metal needs to be treated for recycling, noble metal can cause certain loss in the recovery treatment process, and catalyst cost is increased.
In recent years, ionic liquids have received high attention from academia and industry as a new and novel catalytic material and a green solvent. Patent CN 100389108C discloses a method for preparing caprolactam in an ionic liquid/organic solvent mixed solvent system, which can realize the separation of caprolactam and a catalytic system and realize the recycling of ionic liquid, a catalyst and an organic solvent, and the system is also significant in the hydrogenation process of nitrile rubber.
Disclosure of Invention
The technical problem to be solved by the invention is to provide a method for applying an ionic liquid to hydrogenation and catalyst separation of nitrile rubber, wherein the ionic liquid is used for reducing production cost and improving product performance.
In order to solve the problems, the invention provides a method for hydrogenation and catalyst separation of nitrile rubber by using an ionic liquid, which is characterized by comprising the following steps: adding an ionic liquid and a noble metal catalyst into a nitrile rubber solution with the concentration of 5-25 wt%, reacting in a hydrogen atmosphere, adding a nonpolar solvent after the reaction is finished, and stirring, standing for phase splitting and separating to obtain the noble metal catalyst and a reaction product hydrogenated nitrile rubber respectively; the mass ratio of the organic solvent to the ionic liquid in the nitrile rubber solution is 1: 0.1 to 4; the mass ratio of the nonpolar solvent to the organic solvent is 0.1: 1-10: 1; the noble metalThe amount of the catalyst used was 1X 10 times the mass of the nitrile rubber in the nitrile rubber solution-5 ~ 1×10-2And (4) doubling.
The nitrile rubber solution with the concentration of 5-25 wt% is formed by dissolving nitrile rubber in an organic solvent and uniformly dissolving the nitrile rubber by ultrasonic.
The nitrile rubber is nitrile rubber or valeronitrile rubber.
The organic solvent is one or more of toluene, xylene, chlorobenzene and butanone.
The ionic liquid is one or a mixture of imidazole, pyridine, quaternary ammonium, quaternary phosphonium, pyrrolidine and piperidine ionic liquids.
The cation of the ionic liquid refers to alkyl imidazole cation, alkyl pyridine cation, pyrrolidine cation, piperidine cation, quaternary ammonium salt cation, quaternary phosphonium salt cation and one of derivatives of the cations.
The anion of the ionic liquid is Cl-、HSO4 -、H2PO4 -、BF4 -、CF3Ac-、OTf -、TS-One kind of (1).
The noble metal component in the noble metal catalyst refers to one or more of rhodium, ruthenium, palladium, iridium and platinum.
The nonpolar solvent is one or more of cyclopentane, n-hexane, cyclohexane and n-heptane.
The reaction conditions are that the hydrogen pressure is 0.5-10 MPa, the temperature is 30-190 ℃, and the reaction time is 1-96 h.
Compared with the prior art, the invention has the following advantages:
1. the invention uses a mixed solvent system of ionic liquid and organic solvent which can dissolve homogeneous precious metal catalyst, and the homogeneous precious metal catalyst has higher solubility in the ionic liquid, and the catalyst can shuttle between the two solvents, thereby avoiding the coordination poisoning effect of cyano-functional groups in rubber molecules on central metal atoms, and avoiding the phenomenon that the generated polymerization product wraps the catalyst to deactivate the catalyst.
2. The invention adds non-polar solvent into the reacted system, which can greatly reduce the solubility of catalyst in organic phase, and make the catalyst enter into ionic liquid phase, and the hydrogenated polymerization product is still suspended in organic phase, thus completing the separation of catalyst and product and the recovery of noble metal catalyst through the ionic liquid phase discharged from the bottom of the lower kettle.
3. The ionic liquid/organic solvent mixed solvent system can avoid the inactivation of the catalyst due to the coating of the active center by the polymer, is beneficial to keeping the activity of the catalyst in the hydrogenation reaction process, is easy to separate the catalyst from the product after the reaction, realizes the recycling of the catalyst by settling and separating the ionic liquid, solves the problem that the catalyst cannot be effectively recycled, can reduce the production cost, can improve the product performance, and has good industrial application prospect.
Drawings
The following describes embodiments of the present invention in further detail with reference to the accompanying drawings.
FIG. 1 shows nitrile rubber as a raw material1H NMR spectrum.
FIG. 2 shows the product of hydrogenation of nitrile rubber, hydrogenated nitrile rubber1H NMR spectrum.
Detailed Description
A method for hydrogenation and catalyst separation of an ionic liquid for nitrile rubber is characterized by adding the ionic liquid and a noble metal catalyst into a nitrile rubber solution with the concentration of 5-25 wt%, reacting for 1-96 hours under the conditions of hydrogen atmosphere, pressure of 0.5-10 MPa and temperature of 30-190 ℃, adding a non-polar solvent after the reaction is finished, stirring, standing for phase separation, and separating to obtain the noble metal catalyst and a reaction product hydrogenated nitrile rubber respectively.
Wherein: the mass ratio of the organic solvent to the ionic liquid in the nitrile rubber solution is 1: 0.1 to 4; the mass ratio of the nonpolar solvent to the organic solvent is 0.1: 1-10: 1; the amount of the noble metal catalyst is 1X 10 times of the mass of the nitrile rubber in the nitrile rubber solution-5 ~ 1×10-2And (4) doubling.
The nitrile rubber solution with the concentration of 5-25 wt% is a solution formed by dissolving nitrile rubber in an organic solvent and uniformly dissolving the nitrile rubber by ultrasonic. Nitrile rubber means nitrile rubber or valeronitrile rubber. The organic solvent is one or more of toluene, xylene, chlorobenzene and butanone.
The ionic liquid is one or a mixture of imidazole, pyridine, quaternary ammonium, quaternary phosphonium, pyrrolidine and piperidine ionic liquids.
The cation of the ionic liquid refers to alkyl imidazole cation (1-methylimidazole cation ([ MIm)]+) 1-ethylimidazole cation ([ EIm)]+) 1-butylimidazolium cation ([ BIm)]+) 1-hexylimidazolium cation ([ HIm ]]+) 1-octyl imidazole cation ([ OIm)]+) 1-decylimidazole cation ([ DIm)]+) Alkyl pyridinium cation (N-ethyl pyridinium cation ([ Epy))]+) N-butylpyridinium ([ Bpy)]+) N-hexylpyridinium cation ([ Hpy)]+) N-octyl pyridinium cation ([ Opy)]+) Pyrrolidine cation (N-butyl-N-methylpyrrole cation (PP 1, 4)), piperidine cation (N-butyl-N-methylpiperidine cation (P1, 4)), quaternary ammonium salt cation (R)1R2R3R4N+) And quaternary phosphonium salt cation (R)1R2R3R4P+) And one of the derivatives of the above cations; r, R therein1、R2、R3、R4、R5、R6All of them are C1-C16 alkyl groups.
The anion of the ionic liquid is Cl-、HSO4 -、H2PO4 -、BF4 -、CF3Ac-(trifluoroacetate ion), OTf-(trifluoromethanesulfonate ion), TS-(p-toluenesulfonate ion).
The noble metal component in the noble metal catalyst refers to one or more of rhodium, ruthenium, palladium, iridium and platinum, and includes but is not limited to RhCl (PPh)3)3、RhH(PPh3)4、RuH(CH3CO2)(PPh3)3、RuH2 (PPh3)4And RuCl2 (PPh3)3Palladium acetate, palladium stearate, palladium tartrate, palladium propionate, platinum acetylacetonate, platinum triphenylphosphine chloride, and the like, including but not limited to iridium carbonylbis (triphenylphosphine) chloride, iridium acetylacetonate, and the like.
The nonpolar solvent is one or more of cyclopentane, n-hexane, cyclohexane and n-heptane.
Example 1 a method of using ionic liquid for hydrogenation and catalyst separation of nitrile rubber (alkylimidazolium ionic liquid 1-methylimidazolium tetrafluoroborate ([ MIm ]]BF4) Toluene mixed solvent system):
dissolving 1g of nitrile rubber in 20g of toluene, ultrasonically dissolving to form a 5wt% nitrile rubber-toluene solution, adding the solution into a 100ml high-pressure reaction kettle, and adding 10g of [ MIm ]]BF4Ionic liquid, adding 1 × 10-5 g RhCl(PPh3)3And mechanically stirring uniformly. The autoclave was charged with 2MPa of nitrogen gas to displace the air in the autoclave, and the operation was repeated 3 times, and then the autoclave was charged with 5MPa of hydrogen gas at a reaction temperature of 140 ℃ and reacted for 24 hours with continuous stirring. After the reaction is finished, cooling the reaction kettle to room temperature, reducing the pressure to normal pressure, taking out the reaction mixture, adding 2 g of cyclopentane into the system, stirring, standing for phase separation,1the absolute amount of hydrogenation product in the organic phase was determined by H NMR nuclear magnetic internal standard method.
Of these, the nitrile rubber conversion was 80.0%, the degree of hydrogenation (HD = 80%) and the products were all in the toluene-cyclopentane phase, 85.0% RhCl (PPh)3)315.0% RhCl (PPh) in the ionic liquid phase3)3And is positioned in an organic phase, and the separation of the catalyst and the product is successfully realized.
Example 2 a method of using ionic liquid for hydrogenation and catalyst separation of nitrile rubber (alkylimidazolium ionic liquid 1-ethylimidazolium chloride ([ EIm ] Cl)/chlorobenzene mixed solvent system):
1g of nitrile rubber was dissolved in 20g of chlorobenzeneUltrasonic dissolving to form 5wt% nitrile rubber-chlorobenzene solution, adding the solution into a 100ml high-pressure reaction kettle, adding 10g [ EIm ]]Cl Ionic liquid, 1mg RhH (PPh) was added3)4And mechanically stirring uniformly. The autoclave was charged with 2MPa of nitrogen gas to displace the air in the autoclave, and the operation was repeated 3 times, and then the autoclave was charged with 0.5MPa of hydrogen gas at a reaction temperature of 190 ℃ and reacted for 96 hours with continuous stirring. After the reaction is finished, cooling the reaction kettle to room temperature, reducing the pressure to normal pressure, taking out the reaction mixture, adding 2 g of normal hexane into the system, stirring, standing for phase separation,1the absolute amount of hydrogenation product in the organic phase was determined by H NMR nuclear magnetic internal standard method. Wherein the nitrile rubber conversion was 95%, the degree of hydrogenation (HD = 95%), the product was in the toluene-n-hexane phase, 85% RhCl (PPh)3)315% RhH (PPh) in the Ionic liquid phase3)4And is positioned in an organic phase, and the separation of the catalyst and the product is successfully realized.
Example 3A method of using ionic liquid for hydrogenation and catalyst separation of nitrile rubber (alkylimidazolium ionic liquid 1-butylimidazolium bisulfate ([ BIm)]HSO4) -1-hexylimidazolium fluoroborate ([ HIm ]]BF4) Toluene mixed solvent system):
10g of nitrile rubber is dissolved in 40 g of toluene and dissolved by ultrasound to form a 25 wt.% nitrile rubber-toluene solution, which is introduced into a 100ml autoclave and 5 g [ BIm ]]HSO4And 5 g of [ HIm]BF4Ionic liquid, 5 mg RhH (PPh) was added3)4And 5 mg of palladium acetate, stirred mechanically well. The autoclave was charged with 2MPa of nitrogen gas to displace the air in the autoclave, and the operation was repeated 3 times, and then the autoclave was charged with 3 MPa of hydrogen gas at a reaction temperature of 170 ℃ and reacted for 72 hours with continuous stirring. After the reaction is finished, cooling the reaction kettle to room temperature, reducing the pressure to normal pressure, taking out the reaction mixture, adding 10g of normal hexane into the system, stirring, standing for phase separation,1the absolute amount of hydrogenation product in the organic phase was determined by H NMR nuclear magnetic internal standard method. Wherein the conversion of nitrile rubber is 80.0%, the degree of hydrogenation (HD = 80%), the product is in the toluene-n-hexane phase, 95% RhCl (PPh)3)3In an ionic liquidBulk phase, 5% RhH (PPh)3)4And is positioned in an organic phase, and the separation of the catalyst and the product is successfully realized.
Example 4 method of using an ionic liquid for hydrogenation and catalyst separation of nitrile rubber (alkylimidazolium cation 1-octylimidazole hydrogensulfate ([ OIm)]HSO4) -1-decyl imidazole trifluoroacetate ([ DIm)]CF3Ac)/xylene mixed solvent system):
dissolving 4 g of nitrile rubber in 20g of xylene, ultrasonically dissolving to form 20 wt% nitrile rubber-xylene solution, adding the solution into a 100ml high-pressure reaction kettle, and adding 5 g of [ OIm ]]HSO4And 5 g [ DIm]CF3Ac ion liquid, adding 10 mg RuH (CH)3CO2)(PPh3)3And mechanically stirring uniformly. The autoclave was charged with 2MPa of nitrogen gas to displace the air in the autoclave, and the operation was repeated 3 times, and then the autoclave was charged with 6 MPa of hydrogen gas at a reaction temperature of 190 ℃ and reacted for 96 hours with continuous stirring. After the reaction is finished, cooling the reaction kettle to room temperature, reducing the pressure to normal pressure, taking out the reaction mixture, adding 200 g of cyclohexane into the system, stirring, standing for phase separation,1the absolute amount of hydrogenation product in the organic phase was determined by H NMR nuclear magnetic internal standard method. Wherein the nitrile rubber conversion is 80.0%, the degree of hydrogenation (HD = 80%), the products are in the xylene-cyclohexane phase, 99% RuH (CH)3CO2)(PPh3)31% of RuH (CH) in the Ionic liquid phase3CO2)(PPh3)3And is positioned in an organic phase, and the separation of the catalyst and the product is successfully realized.
Example 5A method of using an ionic liquid for hydrogenation and catalyst separation of nitrile rubber (alkylpyridine ionic liquid N-ethylpyridine hydrogen sulfate ([ Epy ]]HSO4) -N-butylpyridinium trifluoromethanesulfonate ([ Bpy)]Otf)/butanone mixed solvent system):
dissolving 1g of valeronitrile rubber in 20g of butanone, ultrasonically dissolving to form a 5wt% solution of valeronitrile rubber and butanone, adding the solution into a 100ml high-pressure reaction kettle, and adding 10g of Epy]HSO4And 10g [ Bpy]Otf Ionic liquid, 10 mg of RuH (CH) was added3CO2)(PPh3)3And mechanically stirring uniformly. The autoclave was charged with 2MPa of nitrogen gas to displace the air in the autoclave, and the operation was repeated 3 times, and then the autoclave was charged with 10MPa of hydrogen gas at a reaction temperature of 30 ℃ and reacted for 96 hours with continuous stirring. After the reaction is finished, cooling the reaction kettle to room temperature, reducing the pressure to normal pressure, taking out the reaction mixture, adding 20g of n-heptane into the system, stirring, standing for phase separation,1the absolute amount of hydrogenation product in the organic phase was determined by H NMR nuclear magnetic internal standard method. Wherein the nitrile rubber conversion was 20.0%, the degree of hydrogenation (HD = 20%), the product was in the butanone-n-heptane phase, 95% RuH (CH)3CO2)(PPh3)35% RuH (CH) in the Ionic liquid phase3CO2)(PPh3)3And is positioned in an organic phase, and the separation of the catalyst and the product is successfully realized.
Example 6A method of using an ionic liquid for hydrogenation and catalyst separation of nitrile rubber (alkylpyridine ionic liquid N-hexylpyridine p-methylbenzenesulfonate ([ Hpy)]TS) -N-octyl pyridine hydrogen sulfate ([ Opy)]HSO4) Toluene mixed solvent system):
dissolving 1g of nitrile rubber in 10g of toluene, ultrasonically dissolving to form a 10 wt% nitrile rubber-toluene solution, adding the solution into a 100ml high-pressure reaction kettle, and adding 20g of [ Hpy ]]TS and 20g [ Opy]HSO4Ionic liquid, adding 10 mg RuH2 (PPh3)4And mechanically stirring uniformly. The autoclave was charged with 2MPa of nitrogen gas to displace the air in the autoclave, and the operation was repeated 3 times, and then the autoclave was charged with 10MPa of hydrogen gas at a reaction temperature of 100 ℃ and reacted for 48 hours with continuous stirring. After the reaction is finished, cooling the reaction kettle to room temperature, reducing the pressure to normal pressure, taking out the reaction mixture, adding 20g of n-heptane into the system, stirring, standing for phase separation,1the absolute amount of hydrogenation product in the organic phase was determined by H NMR nuclear magnetic internal standard method. Wherein the nitrile rubber conversion is 80.0%, the degree of hydrogenation (HD = 80%), the products are in the toluene-n-heptane phase, 98% RuH2 (PPh3)42% of RuH (CH) in the Ionic liquid phase3CO2)(PPh3)3In organic phase, successfully implementedThe catalyst is now separated from the product.
Example 7 a method of using an ionic liquid for hydrogenation and catalyst separation of nitrile rubber (pyrrolidine cation N-butyl-N-methylpyrrolidine bromide (PP 1,4 Br)/toluene mixed solvent system):
dissolving 1g of nitrile rubber in 10g of toluene, ultrasonically dissolving to form a 10 wt% nitrile rubber-toluene solution, adding the solution into a 100ml high-pressure reaction kettle, adding 1g of PP1,4Br ionic liquid, and adding 10 mg of RuCl2(PPh3)3And mechanically stirring uniformly. 2MPa of nitrogen is filled into the high-pressure kettle, air in the reaction kettle is replaced, the operation is repeated for 3 times, then, 3 MPa of hydrogen is filled into the reaction kettle, the reaction temperature is 150 ℃, and the reaction is carried out for 96 hours under continuous stirring. After the reaction is finished, cooling the reaction kettle to room temperature, reducing the pressure to normal pressure, taking out the reaction mixture, adding 20g of n-heptane into the system, stirring, standing for phase separation, and determining the absolute amount of the hydrogenation product in the organic phase by an internal standard method. Wherein the nitrile rubber conversion is 60.0%, the degree of hydrogenation (HD = 60%), the products are in the toluene-n-heptane phase, 80% RuH2 (PPh3)420% of RuH (CH) in the ionic liquid phase3CO2)(PPh3)3And is positioned in an organic phase, and the separation of the catalyst and the product is successfully realized.
Example 8 method of Using Ionic liquid for hydrogenation and catalyst separation of nitrile rubber (piperidine Ionic liquid N-butyl-N-methylpiperidine tetrafluoroborate (P1, 4 BF)4) Toluene mixed solvent system):
dissolving 1g of nitrile rubber in 10g of toluene, ultrasonically dissolving to form a 10 wt% nitrile rubber-toluene solution, adding the solution into a 100ml high-pressure reaction kettle, and adding 10g P1,4BF410 mg of palladium acetate is added into the ionic liquid, and the ionic liquid is mechanically stirred uniformly. 2MPa of nitrogen is filled into the high-pressure kettle, air in the reaction kettle is replaced, the operation is repeated for 3 times, then 5MPa of hydrogen is filled into the reaction kettle, the reaction temperature is 150 ℃, and the reaction is carried out for 1 hour under continuous stirring. After the reaction is finished, cooling the reaction kettle to room temperature, reducing the pressure to normal pressure, taking out the reaction mixture, adding 20g of n-heptane into the system, stirring, standing stillAnd (4) phase separation and an internal standard method are adopted to determine the absolute amount of hydrogenation products in the organic phase. Wherein the conversion rate of the nitrile rubber is 20.0 percent, the hydrogenation degree (HD =20 percent), the products are all in a toluene-n-heptane phase, 98 percent of palladium acetate is in an ionic liquid phase, 2 percent of palladium acetate is in an organic phase, and the separation of the catalyst and the products is successfully realized.
Example 9A method of using an ionic liquid for hydrogenation and catalyst separation of nitrile rubber (Quaternary phosphonium salt Ionic liquid Tetrabutylphosphine tetrafluoroborate (P)4,4,4,4BF4) Toluene mixed solvent system):
dissolving 1g of nitrile rubber in 10g of toluene, ultrasonically dissolving to form a 10 wt% nitrile rubber-toluene solution, adding the solution into a 100ml high-pressure reaction kettle, and adding 20g P4,4,4,4BF410 mg of palladium stearate is added into the ionic liquid, and the ionic liquid is mechanically stirred uniformly. The autoclave was charged with 2MPa of nitrogen gas to displace the air in the autoclave, and the operation was repeated 3 times, and then the autoclave was charged with 5MPa of hydrogen gas at a reaction temperature of 150 ℃ and reacted for 96 hours with continuous stirring. After the reaction is finished, cooling the reaction kettle to room temperature, reducing the pressure to normal pressure, taking out the reaction mixture, adding 20g of n-heptane into the system, stirring, standing for phase separation, and determining the absolute amount of the hydrogenation product in the organic phase by an internal standard method. Wherein the conversion rate of the nitrile rubber is 60.0 percent, the hydrogenation degree (HD =60 percent), the products are all in a toluene-n-heptane phase, 98 percent of palladium stearate is positioned in an ionic liquid phase, 2 percent of palladium stearate is positioned in an organic phase, and the separation of the catalyst and the products is successfully realized.
Example 10A method of using an ionic liquid for hydrogenation and catalyst separation of nitrile rubber (quaternary phosphonium salt ionic liquid tetrabutyl phosphine tetrafluoroborate (P)4,4,4,4BF4) Toluene mixed solvent system):
dissolving 1g of nitrile rubber in 10g of toluene, ultrasonically dissolving to form a 10 wt% nitrile rubber-toluene solution, adding the solution into a 100ml high-pressure reaction kettle, and adding 20g P4,4,4,4BF410 mg of palladium tartrate is added into the ionic liquid, and the ionic liquid is mechanically stirred uniformly. 2MPa of nitrogen is filled into the autoclave to replace the air in the autoclave, and the process is repeatedThe operation is carried out for 3 times, then hydrogen is filled into the reaction kettle for 5MPa, the reaction temperature is 150 ℃, and the reaction is carried out for 96 hours under continuous stirring. After the reaction is finished, cooling the reaction kettle to room temperature, reducing the pressure to normal pressure, taking out the reaction mixture, adding 20g of n-heptane into the system, stirring, standing for phase separation, and determining the absolute amount of the hydrogenation product in the organic phase by an internal standard method. Wherein the conversion rate of the nitrile rubber is 60.0 percent, the hydrogenation degree (HD =60 percent), the products are all in a toluene-n-heptane phase, 98 percent of palladium tartrate is in an ionic liquid phase, 2 percent of palladium tartrate is in an organic phase, and the separation of the catalyst and the products is successfully realized.
Example 11A method of using an ionic liquid for hydrogenation and catalyst separation of nitrile rubber (Quaternary phosphonium salt Ionic liquid Tetrabutylphosphine tetrafluoroborate (P)4,4,4,4BF4) Toluene mixed solvent system):
dissolving 1g of nitrile rubber in 10g of toluene, ultrasonically dissolving to form a 10 wt% nitrile rubber-toluene solution, adding the solution into a 100ml high-pressure reaction kettle, and adding 20g P4,4,4,4BF410 mg of palladium propionate is added into the ionic liquid, and the ionic liquid is mechanically stirred uniformly. The autoclave was charged with 2MPa of nitrogen gas to displace the air in the autoclave, and the operation was repeated 3 times, and then the autoclave was charged with 5MPa of hydrogen gas at a reaction temperature of 150 ℃ and reacted for 96 hours with continuous stirring. After the reaction is finished, cooling the reaction kettle to room temperature, reducing the pressure to normal pressure, taking out the reaction mixture, adding 20g of n-heptane into the system, stirring, standing for phase separation, and determining the absolute amount of the hydrogenation product in the organic phase by an internal standard method. Wherein the conversion rate of the nitrile rubber is 60.0 percent, the hydrogenation degree (HD =60 percent), the products are all in a toluene-n-heptane phase, 95 percent of palladium propionate is in an ionic liquid phase, 5 percent of palladium propionate is in an organic phase, and the separation of the catalyst and the products is successfully realized.
Example 12A method of using an ionic liquid for hydrogenation and catalyst separation of nitrile rubber (Quaternary phosphonium salt Ionic liquid Tetrabutylphosphine tetrafluoroborate (P)4,4,4,4BF4) Toluene mixed solvent system):
dissolving 1g of nitrile rubber in 10g of toluene, carrying out ultrasonic dissolution to form a 10 wt% nitrile rubber-toluene solution,the solution was charged to a 100ml autoclave and 20g P added4,4,4,4BF410 mg of platinum acetylacetonate is added into the ionic liquid, and the mixture is mechanically stirred uniformly. The autoclave was charged with 2MPa of nitrogen gas to displace the air in the autoclave, and the operation was repeated 3 times, and then the autoclave was charged with 5MPa of hydrogen gas at a reaction temperature of 150 ℃ and reacted for 96 hours with continuous stirring. After the reaction is finished, cooling the reaction kettle to room temperature, reducing the pressure to normal pressure, taking out the reaction mixture, adding 20g of n-heptane into the system, stirring, standing for phase separation, and determining the absolute amount of the hydrogenation product in the organic phase by an internal standard method. Wherein the conversion rate of the nitrile rubber is 40.0 percent, the hydrogenation degree (HD =40 percent), the products are all in a toluene-n-heptane phase, 90 percent of platinum acetylacetonate is located in an ionic liquid phase, and 10 percent of platinum acetylacetonate is located in an organic phase, and the separation of the catalyst and the products is successfully realized.
Example 13A method of using an ionic liquid for hydrogenation and catalyst separation of nitrile rubber (Quaternary phosphonium salt Ionic liquid Tetrabutylphosphine Tetrafluoroborate (P)4,4,4,4BF4) Toluene mixed solvent system):
dissolving 1g of nitrile rubber in 10g of toluene, ultrasonically dissolving to form a 10 wt% nitrile rubber-toluene solution, adding the solution into a 100ml high-pressure reaction kettle, and adding 20g P4,4,4,4BF410 mg of triphenylphosphine platinum chloride is added into the ionic liquid, and the mixture is mechanically stirred uniformly. The autoclave was charged with 2MPa of nitrogen gas to displace the air in the autoclave, and the operation was repeated 3 times, and then the autoclave was charged with 5MPa of hydrogen gas at a reaction temperature of 150 ℃ and reacted for 96 hours with continuous stirring. After the reaction is finished, cooling the reaction kettle to room temperature, reducing the pressure to normal pressure, taking out the reaction mixture, adding 20g of n-heptane into the system, stirring, standing for phase separation, and determining the absolute amount of the hydrogenation product in the organic phase by an internal standard method. Wherein the conversion rate of the nitrile rubber is 40.0 percent, the hydrogenation degree (HD =40 percent), the products are all in a toluene-n-heptane phase, 90 percent of triphenylphosphine platinum chloride is in an ionic liquid phase, 10 percent of triphenylphosphine platinum chloride is in an organic phase, and the separation of the catalyst and the products is successfully realized.
EXAMPLE 14 use of an Ionic liquid for addition of nitrile rubberMethod for separating hydrogen and catalyst (quaternary phosphonium salt ionic liquid tetrabutyl phosphine tetrafluoroborate (P)4,4,4,4BF4) Toluene mixed solvent system):
dissolving 1g of nitrile rubber in 10g of toluene, ultrasonically dissolving to form a 10 wt% nitrile rubber-toluene solution, adding the solution into a 100ml high-pressure reaction kettle, and adding 20g P4,4,4,4BF410 mg of iridium carbonylbis (triphenylphosphine) chloride is added into the ionic liquid, and the ionic liquid is mechanically stirred uniformly. The autoclave was charged with 2MPa of nitrogen gas to displace the air in the autoclave, and the operation was repeated 3 times, and then the autoclave was charged with 5MPa of hydrogen gas at a reaction temperature of 150 ℃ and reacted for 96 hours with continuous stirring. After the reaction is finished, cooling the reaction kettle to room temperature, reducing the pressure to normal pressure, taking out the reaction mixture, adding 20g of n-heptane into the system, stirring, standing for phase separation, and determining the absolute amount of the hydrogenation product in the organic phase by an internal standard method. Wherein the conversion rate of the nitrile rubber is 55.0%, the hydrogenation degree (HD = 55%), the products are all in a toluene-n-heptane phase, 90% of the iridium carbonyl bis (triphenylphosphine) chloride is in an ionic liquid phase, and 10% of the iridium carbonyl bis (triphenylphosphine) chloride is in an organic phase, and the separation of the catalyst and the products is successfully realized.
Example 15 method of Using Ionic liquid for hydrogenation and catalyst separation of nitrile rubber (Quaternary phosphonium salt cation tetrabutylphosphonium tetrafluoroborate (P)4,4,4,4BF4) Toluene mixed solvent system):
dissolving 1g of nitrile rubber in 10g of toluene, ultrasonically dissolving to form a 10 wt% nitrile rubber-toluene solution, adding the solution into a 100ml high-pressure reaction kettle, adding 40 g P4,4,4,4BF410 mg of iridium acetylacetonate is added into the ionic liquid, and the mixture is mechanically stirred uniformly. The autoclave was charged with 2MPa of nitrogen gas to displace the air in the autoclave, and the operation was repeated 3 times, and then the autoclave was charged with 5MPa of hydrogen gas at a reaction temperature of 150 ℃ and reacted for 96 hours with continuous stirring. After the reaction is finished, cooling the reaction kettle to room temperature, reducing the pressure to normal pressure, taking out the reaction mixture, adding 20g of n-heptane into the system, stirring, statically carrying out phase separation, and determining the absolute value of the hydrogenation product in the organic phase by an internal standard methodAmount of the compound (A). Wherein the conversion rate of the nitrile rubber is 50.0 percent, the hydrogenation degree (HD =50 percent), the products are all in a toluene-n-heptane phase, 90 percent of acetylacetone iridium is in an ionic liquid phase, 10 percent of acetylacetone iridium is in an organic phase, and the separation of the catalyst and the products is successfully realized.
Example 16 method of Using Ionic liquids for hydrogenation and catalyst separation of nitrile rubber (alkylimidazolium Ionic liquid 1-methylimidazolium tetrafluoroborate ([ MIm ]]BF4) Toluene mixed solvent system):
dissolving 1g of nitrile rubber in 10g of toluene, ultrasonically dissolving to form a 10 wt% nitrile rubber-toluene solution, adding the solution into a 100ml high-pressure reaction kettle, and adding 10g of [ MIm ]]BF4Ionic liquid, 2 mg RhCl (PPh) was added3)3And mechanically stirring uniformly. The autoclave was charged with 2MPa of nitrogen gas to displace the air in the autoclave, and the operation was repeated 3 times, and then the autoclave was charged with 5MPa of hydrogen gas at a reaction temperature of 160 ℃ and reacted for 24 hours with continuous stirring. After the reaction is finished, cooling the reaction kettle to room temperature, reducing the pressure to normal pressure, taking out the reaction mixture, adding 2 g of cyclopentane into the system, stirring, standing for phase separation,1the absolute amount of hydrogenation product in the organic phase was determined by H NMR nuclear magnetic internal standard method. Of these, the nitrile rubber conversion was 90%, the degree of hydrogenation (HD = 90%) and the products were all in the toluene-cyclopentane phase, 85.0% RhCl (PPh)3)315.0% RhCl (PPh) in the ionic liquid phase3)3And is positioned in an organic phase, and the separation of the catalyst and the product is successfully realized.
Example 17 method of Using Ionic liquids for hydrogenation and catalyst separation of nitrile rubber (alkylimidazolium Ionic liquid 1-methylimidazolium tetrafluoroborate ([ MIm ]]BF4) Toluene mixed solvent system):
dissolving 1g of nitrile rubber in 20g of chlorobenzene, carrying out ultrasonic dissolution to form a nitrile rubber-toluene solution with the concentration of 5wt%, adding the solution into a 100ml high-pressure reaction kettle, and adding 10g of [ MIm ]]BF4Ionic liquid, 2 mg RhCl (PPh) was added3)3And mechanically stirring uniformly. Filling 2MPa nitrogen into the autoclave, replacing the air in the autoclave, repeating the operation for 3 timesAnd then filling hydrogen into the reaction kettle at 5MPa, wherein the reaction temperature is 190 ℃, and reacting for 24 hours under continuous stirring. After the reaction is finished, cooling the reaction kettle to room temperature, reducing the pressure to normal pressure, taking out the reaction mixture, adding 2 g of cyclopentane into the system, stirring, standing for phase separation,1the absolute amount of hydrogenation product in the organic phase was determined by H NMR nuclear magnetic internal standard method. Of these, the nitrile rubber conversion was 99.0%, fully hydrogenated (HD = 99%) and the products were all in the toluene-cyclopentane phase, 85.0% RhCl (PPh)3)315.0% RhCl (PPh) in the ionic liquid phase3)3And is positioned in an organic phase, and the separation of the catalyst and the product is successfully realized.
Of the resulting product1H NMR spectrum (see FIG. 2) of nitrile rubber as raw material1By comparison of the H NMR spectra (see FIG. 1), it can be seen that: after hydrotreating, H assigned to the 1,2-C = C double bond at a chemical shift of 4.9-5.1 ppm and H assigned to the 1,4-C = C double bond at a chemical shift of 5.3-5.6 ppm disappeared, indicating that the hydrogenation of the unsaturated C = C double bond was completed.
Comparative examples 1-2 illustrate that hydrogenation of nitrile rubber occurs and separation of noble metal catalyst from product is achieved in the prior art.
Comparative example 1
Dissolving 1g of nitrile rubber in 10g of toluene, ultrasonically dissolving to form a 10 wt% nitrile rubber-toluene solution, adding the solution to a 100ml autoclave, and adding 2 mg of RhCl (PPh)3)3And mechanically stirring uniformly. The autoclave was charged with 2MPa of nitrogen gas to displace the air in the autoclave, and the operation was repeated 3 times, and then the autoclave was charged with 5MPa of hydrogen gas at a reaction temperature of 160 ℃ and reacted for 24 hours with continuous stirring. After the reaction is finished, cooling the reaction kettle to room temperature, reducing the pressure to normal pressure, taking out the reaction mixture, and determining the absolute amount of the hydrogenation product in the organic phase by an internal standard method. The nitrile rubber conversion was 50.0%, and the degree of hydrogenation (HD = 50%).
Comparative example 2
Dissolving 1g of nitrile rubber in 20g of chlorobenzene, ultrasonically dissolving to form a 5wt% nitrile rubber-chlorobenzene solution, adding the solution to a 100ml autoclave, adding 2 mg of RhCl (PPh)3)3And mechanically stirring uniformly. Filling 2MPa nitrogen into the autoclave to replace the air in the autoclave, repeating the operation for 3 times, then filling 5MPa hydrogen into the autoclave, reacting at 190 ℃ and reacting for 24 hours under continuous stirring. After the reaction is finished, cooling the reaction kettle to room temperature, reducing the pressure to normal pressure, taking out the reaction mixture, and determining the absolute amount of the hydrogenation product in the organic phase by an internal standard method. The nitrile rubber conversion was 60.0%, and the degree of hydrogenation (HD = 60%).
Table 1: evaluation results and separation of catalysts used in examples 1 to 16 and comparative examples 1 to 2
As can be seen from Table 1, in the comparative example, no ionic liquid was added, and the conversion of the final reaction was lower than in the examples to which an ionic liquid was added (example 16 vs. comparative example 1; example 17 vs. comparative example 2). The reason is that the polymerization product of the comparative example forms a micelle in the reaction process, the catalyst is wrapped by the polymerization product and loses the catalytic activity, and the catalyst can shuttle in a mixed solvent due to the addition of the ionic liquid in the example, so that the catalyst is prevented from being wrapped by the polymer in the same phase for a long time. In addition, in the comparative example, the product and the catalyst after reaction are both dissolved in an organic solvent, and need to be separated by high-temperature flash evaporation, so that the separation cost is remarkably increased, in the example, after the temperature is reduced to room temperature, the catalyst can enter an ionic liquid phase from the organic phase by adding a nonpolar solvent, so that the product and the catalyst can be further settled, the ionic liquid in which the catalyst is dissolved can be directly used for the next cycle, and the separation cost of the catalyst is saved.