Method for copolymerizing isobutylene with maleic anhydride

Abstract

The present invention relates to a method for copolymerizing isobutylene and maleic anhydride, comprising the following steps: S1, introducing isobutylene and a maleic anhydride solution containing an initiator into a supergravity reactor, so that the isobutylene and the maleic anhydride are mixed and pre-reacted; S2, introducing the liquid phase product obtained in step S1 into a reaction tube reactor to continue the reaction. The present invention provides a new method for polar copolymerization of isobutylene, which fully mixes isobutylene and maleic anhydride in a very short time by means of a supergravity reactor plus a reaction tube reactor, and accelerates the efficiency of further polar copolymerization reaction by controlling the time, temperature and concentration distribution of the polar reaction, shortens the reaction time of further polar copolymerization, reduces the cost of polar reaction, and improves the generation rate of reactants; and provides a more feasible method for efficiently producing isobutylene polar copolymers.

Description

Technical Field

[0001] The invention relates to the field of polar polymerization, in particular to a method for preparing an isobutylene maleic anhydride polar copolymer. Background Art

[0002] Isobutylene maleic anhydride copolymers have different uses for different molecular weights and functional groups (amide-amine type, imide type, cross-linking type, hydrolysis type, ion type and other derivative products). They are widely used chemical products. Low molecular weight isobutylene maleic anhydride copolymers can be used as scale inhibitors, dispersants, and water reducers for cement slurry. Medium and high molecular weight isobutylene maleic anhydride copolymers can be used as adhesives for wood and paper processing, emulsion polymerization stabilizers, etc. The anhydride groups in isobutylene maleic anhydride copolymers can undergo esterification, amidation, imidization and ionization reactions, further expanding their application range. After ammoniation, isobutylene maleic anhydride copolymers can be used as adhesives, water-based coatings, etc., after imide modification, they can be used as polymerization stabilizers and bonding latex, and after cross-linking, they can be used as water-absorbing resins. They have excellent performance and wide application, and have important application prospects. At present, there is no mature preparation technology for similar products in China.

[0003] According to the three documents "Research on Isobutylene-Maleic Anhydride Copolymerization" in "Petrochemical Industry" No. 11, 1990, P739-744, "Synthesis and Characterization of IBMA Resin" in "Polymer Materials Science and Engineering" No. 2, 1992, P38-43, and "Research on the Synthesis of Isobutylene-Maleic Anhydride Copolymer" in "Industrial Water Treatment" Vol. 33, No. 9, 2013, P56-59, isobutylene-maleic anhydride copolymer is mainly synthesized by precipitation polymerization. Isobutylene is a gas at room temperature. If it is polarly copolymerized with maleic anhydride, the commonly used method is to directly pass isobutylene into the maleic anhydride solution. This method takes a long time for isobutylene to dissolve and has a low utilization efficiency. It is also possible to liquefy isobutylene and then add it to the maleic anhydride solution, but this method is more expensive. In order to shorten the dissolution time of isobutylene, improve the efficiency of the copolymerization reaction of isobutylene and maleic anhydride, and shorten the reaction time, the prior art does not disclose relevant reaction devices and reaction methods. Summary of the invention

[0004] The object of the present invention is to provide a method for copolymerizing isobutylene and maleic anhydride, so as to solve the problems of low polar copolymerization efficiency and long copolymerization reaction time encountered in the polymerization production of isobutylene polar copolymers in the prior art.

[0005] To achieve the above object, the present invention provides a method for copolymerizing isobutylene and maleic anhydride, comprising the following steps:

[0006] S1, introducing isobutylene and a maleic anhydride solution containing an initiator into a supergravity reactor to mix the isobutylene and the maleic anhydride and perform a pre-reaction;

[0007] S2, introducing the liquid product obtained in step S1 into a reaction tube reactor to continue the reaction.

[0008] In the method for copolymerizing isobutylene and maleic anhydride of the present invention, the pre-reaction time in step S1 is 1 to 4 seconds, the pressure is 0.1 to 0.8 MPa, and the reaction temperature is 55 to 100°C.

[0009] In the method for copolymerizing isobutylene and maleic anhydride of the present invention, the reaction time in step S2 is 1 to 4 hours, the pressure is 0.2 to 2 MPa, and the reaction temperature is 50 to 100° C.

[0010] In the method for copolymerizing isobutylene and maleic anhydride of the present invention, the rotation speed of the supergravity reactor in step S1 is 100 rpm to 2000 rpm; preferably, the rotation speed is 300 rpm to 2000 rpm.

[0011] The method for copolymerizing isobutylene and maleic anhydride of the present invention, wherein in step S1, the volume ratio of isobutylene to the maleic anhydride solution containing an initiator is 50-500:1.

[0012] In the method for copolymerizing isobutylene and maleic anhydride of the present invention, the weight ratio of isobutylene to maleic anhydride is 0.2-5:1, preferably, the weight ratio is 0.5-3:1.

[0013] In the method for copolymerizing isobutylene and maleic anhydride of the present invention, the amount of the initiator is 1%-20% of the weight of the maleic anhydride.

[0014] The method for copolymerizing isobutylene and maleic anhydride of the present invention comprises the following steps: the concentration of maleic anhydride in the maleic anhydride solution containing an initiator is 3wt% to 25wt%, and the solvent for dissolving the maleic anhydride and the initiator is at least one of an organic acid alkyl ester, an alkane and an aromatic hydrocarbon.

[0015] The method for copolymerizing isobutylene and maleic anhydride of the present invention, wherein the initiator is a thermal decomposition type initiator, including at least one of dibenzoyl peroxide, diisopropyl peroxide, di-tert-butyl peroxide, dodecyl peroxide, tert-butyl perbenzoate, diisopropyl peroxydicarbonate, dicarbonyl peroxide, azobisisobutyronitrile and azobisisoheptylonitrile.

[0016] The method for copolymerizing isobutylene and maleic anhydride of the present invention, wherein the reaction tube reactor comprises a shell, and a liquid phase inlet and a liquid phase outlet are respectively provided at two ends of the shell, and a plurality of hollow flow guide tubes are provided in the shell, and one end of the plurality of hollow flow guide tubes is connected to the liquid phase inlet, and the other end is connected to the liquid phase outlet.

[0017] In the method for copolymerization of isobutylene and maleic anhydride of the present invention, the inner diameter of the flow guide tube is 3-6 cm, the number of the flow guide tubes is 3-10, and the length is 8-16 cm, preferably, the length is 10 cm.

[0018] In the method for copolymerizing isobutylene and maleic anhydride of the present invention, a pressure control valve is provided on the reaction tube reactor, and the pressure control range is 0-10MPa.

[0019] The method for copolymerizing isobutylene and maleic anhydride of the present invention further comprises a separation step after step S2 is completed, wherein the liquid-solid blended product obtained in step S2 is separated, and then the solid phase product is washed and dried.

[0020] The method for copolymerizing isobutylene and maleic anhydride of the present invention comprises the following steps: the separation method is filtration separation or centrifugal separation, the liquid phase product after separation is recycled, the washing liquid used for washing is an alcohol liquid, and the drying method is drying.

[0021] The beneficial effects of the present invention are:

[0022] 1. In view of the characteristics of the reaction between isobutylene and maleic anhydride, the process intensification equipment ultra-gravity reactor is introduced into the polar copolymerization reaction. Compared with the reactor, the ultra-gravity reactor can enhance the mass transfer efficiency of isobutylene, reduce the dissolution time of isobutylene, and improve the reaction efficiency of isobutylene.

[0023] 2. In view of the characteristics of the reaction between isobutylene and maleic anhydride, a reaction tube reactor is introduced into the polar copolymerization reaction. Compared with the reactor, the reaction tube can effectively remove the reaction heat, accurately control the reaction temperature, achieve effective requirements for residence time, control the concentration distribution of the reactants, and finally produce a uniform isobutylene polar copolymer, and can effectively improve the conversion rate of the reaction.

[0024] Through the above technical scheme, the present invention provides a new method for polar copolymerization of isobutylene, which makes isobutylene and maleic anhydride fully blended in a very short time by means of a supergravity reactor plus a reaction tube reactor, and accelerates the efficiency of further polar copolymerization reaction by controlling the time, temperature and concentration distribution of the polar reaction, shortens the reaction time of further polar copolymerization, reduces the cost of polar reaction, and improves the generation rate of reactants; and provides a more feasible method for efficiently producing isobutylene polar copolymers. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 The process flow chart of the copolymerization of isobutylene and maleic anhydride of the present invention;

[0026] Figure 2 This is the infrared spectrum of the polymer obtained in Example 5 of the present invention. DETAILED DESCRIPTION

[0027] The present invention is described in detail below by way of examples. It is necessary to point out that the following examples are only used to further illustrate the present invention and cannot be understood as limiting the scope of protection of the present invention. Those skilled in the art in this field can make some non-essential improvements and adjustments to the present invention based on the above content of the present invention.

[0028] A method for polar copolymerization of isobutylene, the method comprising the following steps:

[0029] (1) After nitrogen purging, isobutylene heated to 55-100° C. is contacted with a maleic anhydride solution containing an initiator heated to 55-100° C. in a supergravity reactor to allow the isobutylene and maleic anhydride to be fully mixed and undergo a preliminary polar copolymerization reaction; the residence time of the reaction monomer passing through the supergravity reactor is 1-4 seconds, and the outlet temperature is 50-100° C.;

[0030] (2) After the liquid product obtained in step (1) is completely introduced into the reaction tube reactor through a buffer tank and a metering pump, the polar copolymerization reaction of isobutylene and maleic anhydride is continued; wherein the volatilized isobutylene can be recycled, the copolymerization reaction temperature is 50-100° C., the copolymerization reaction pressure is 0.2-2 MPa, and the copolymerization reaction time is 1-4 h;

[0031] (3) After separating the liquid-solid blended product obtained in step (2), the solid phase product is washed and dried to obtain a solid product which is a polar copolymer with maleic anhydride functional groups.

[0032] like Figure 1 As shown, the heated isobutylene and the maleic anhydride solution containing the initiator are added to the supergravity reactor through a metering pump, the isobutylene enters the supergravity reactor from the gas phase inlet, and the maleic anhydride solution containing the initiator enters the supergravity reactor from the liquid phase inlet, and is fully mixed and subjected to a preliminary polar copolymerization reaction. The unreacted gas phase isobutylene is circulated to the gas phase inlet of the supergravity reactor, and the obtained liquid phase product enters the reaction tube reactor through a buffer tank and a metering pump to continue the reaction. The gas phase isobutylene that fails to participate in the reaction during the reaction is circulated to the gas phase inlet of the supergravity reactor for recycling. After the reaction is completed, the liquid phase product is separated and circulated to the liquid phase inlet of the supergravity reactor for recycling. The solid phase product is washed and dried to finally obtain an isobutylene-maleic anhydride polar copolymer.

[0033] Isobutylene and the maleic anhydride solution containing the initiator can be mixed and initially reacted in a supergravity reactor in a gas-liquid countercurrent, gas-liquid cocurrent or gas-liquid baffled manner. The supergravity reactor used can fully and quickly dissolve the isobutylene gas and the maleic anhydride solution containing the initiator, and complete the initial polar copolymerization reaction.

[0034] Compared with ordinary reactors, the reaction tube reactor used in the present invention can effectively remove the polymerization heat of polar copolymerization reactions and better control the polymerization reaction temperature; provide the necessary residence time for the reaction materials; provide the necessary material mixing conditions to ensure a relatively uniform concentration distribution in the reactor; and have low operating costs.

[0035] Example 1

[0036] After nitrogen was purged into the ultragravity reactor, 1.4 L of isoamyl acetate solution containing 3.1 g of azobisisobutyronitrile and 196 g of maleic anhydride was heated to 60° C. after heat exchange and entered the liquid phase inlet of the ultragravity reactor through a metering pump. Isobutylene was heated to 60° C. after heat exchange and entered the gas phase inlet through a metering pump. The gas and liquid were fully mixed in the ultragravity reactor and a preliminary reaction was carried out. Among them, the gas-liquid ratio in the ultragravity reactor was 400:1 (v / v), and the operating pressure was 0.6 MPa.

[0037] The liquid product obtained from the ultra-gravity reactor is introduced into the reaction tube through a buffer tank and a metering pump to continue the copolymerization reaction of isobutylene and maleic anhydride. The reaction temperature is 60°C, the reaction pressure is 0.6MPa, the number of reaction tubes is 10, the inner diameter of the reaction tube is 5cm, and the reaction time is 3h;

[0038] The obtained liquid-solid blended product was filtered and separated, and then the solid phase product was washed and dried with ethanol to obtain a white isobutylene maleic anhydride copolymer powder.

[0039] Table 1 shows the residence time of gas and liquid in the high gravity reactor and the yield of copolymer when the rotation speed of the high gravity reactor is changed.

[0040] Table 1

[0041] Serial number Super gravity speed Dwell time Copolymer quality Number average molecular weight of copolymer 1 500 4 252g 51000 2 1000 2.5 277g 69000 3 1500 2 269g 63000 4 2000 1 264g 59000

[0042] Example 2

[0043] After nitrogen was purged into the supergravity reactor, 1.4 L of isoamyl acetate amine solution containing 3.1 g of azobisisobutyronitrile and 196 g of maleic anhydride was heated to 60° C. after heat exchange and entered the liquid phase inlet of the supergravity reactor through a metering pump. Isobutylene was heated to 60° C. after heat exchange and entered the gas phase inlet through a metering pump. The gas and liquid were fully mixed in the supergravity reactor and a preliminary reaction was carried out; wherein the rotation speed in the supergravity reactor was 1000 rpm, the operating pressure was 0.6 MPa, and the gas-liquid residence time was 2.5 seconds.

[0044] The liquid product obtained from the ultra-gravity reactor is introduced into the reaction tube through a buffer tank and a metering pump to continue the copolymerization reaction of isobutylene and maleic anhydride. The reaction temperature is 60°C, the reaction pressure is 0.6MPa, the number of reaction tubes is 10, the inner diameter of the reaction tube is 5cm, and the reaction time is 3h;

[0045] The obtained liquid-solid blended product was filtered and separated, and then the solid phase product was washed and dried with ethanol to obtain a white isobutylene maleic anhydride copolymer powder.

[0046] Table 2 shows the changes in the gas-liquid ratio of the high gravity reactor and the yield of the copolymer.

[0047] Table 2

[0048] Serial number Gas-Liquid Ratio Copolymer quality Number average molecular weight of copolymer 1 100 260g 61000 2 300 288g 72000 3 400 277g 69000 4 500 274g 67000

[0049] Example 3

[0050] After nitrogen was purged into the ultragravity reactor, 1.4 L of butyl acetate solution containing 3.1 g of benzoyl peroxide and 196 g of maleic anhydride was heated to 60° C. after heat exchange and introduced into the liquid phase inlet of the ultragravity reactor through a metering pump. Isobutylene was heated to 60° C. after heat exchange and introduced into the gas phase inlet through a metering pump. The gas and liquid were fully mixed in the ultragravity reactor and a preliminary reaction was carried out. Among them, the gas-liquid ratio in the ultragravity reactor was 300:1 (v / v), the rotation speed was 1000 rpm, and the gas-liquid residence time was 2.5 s.

[0051] The liquid product obtained from the ultra-gravity reactor is introduced into the reaction tube through a buffer tank and a metering pump to continue the polar copolymerization reaction of isobutylene and maleic anhydride. The reaction temperature is 60°C, the reaction pressure is 0.6MPa, the number of reaction tubes is 10, the inner diameter of the reaction tube is 5cm, and the reaction time is 3h;

[0052] The obtained liquid-solid blended product was filtered and separated, and then the solid phase product was washed and dried with ethanol to obtain a white isobutylene maleic anhydride copolymer powder.

[0053] Table 3 shows the changes in the operating pressure of the high gravity reactor and the yield of the copolymer.

[0054] Table 3

[0055] Serial number Hypergravity pressure Copolymer quality Number average molecular weight of copolymer 1 0.2Mpa 268g 67000 2 0.6Mpa 288g 72000 3 1Mpa 291g 74000 4 2Mpa 300g 75000

[0056] Example 4

[0057] After nitrogen was purged into the supergravity reactor, 1.4 L of butyl acetate solution containing 3.1 g of benzoyl peroxide and 196 g of maleic anhydride was subjected to heat exchange and then entered the liquid phase inlet of the supergravity reactor through a metering pump. Isobutylene was subjected to heat exchange and then entered the gas phase inlet through a flowmeter. The gas and liquid were fully mixed in the supergravity reactor and a preliminary reaction was carried out. Among them, the gas-liquid ratio in the supergravity reactor was 300:1 (v / v), the rotation speed was 1000 rpm, the operating pressure was 0.6 MPa, and the residence time was 2.5 s.

[0058] The liquid product obtained from the ultra-gravity reactor is introduced into the reaction tube through a buffer tank and a metering pump to continue the polar copolymerization reaction of isobutylene and maleic anhydride. The reaction temperature is 60°C, the reaction pressure is 0.6MPa, the number of reaction tubes is 10, the inner diameter of the reaction tube is 5cm, and the reaction time is 3h;

[0059] The obtained liquid-solid blended product was filtered and separated, and then the solid phase product was washed and dried with ethanol to obtain a white isobutylene maleic anhydride copolymer powder.

[0060] Table 4 shows the changes in the inlet temperature of the high gravity reactor and the yield of the copolymer.

[0061] Table 4

[0062] Serial number High gravity inlet temperature Copolymer quality Number average molecular weight of copolymer 1 55℃ 266g 79000 2 75℃ 298g 65000 3 90℃ 300g 51000

[0063] Example 5

[0064] After nitrogen was purged through the ultragravity reactor, 1.4 L of isoamyl acetate solution containing 3.1 g of azobisisobutyronitrile and 196 g of maleic anhydride was heated to 75° C. after heat exchange and entered the liquid phase inlet of the ultragravity reactor through a metering pump. Isobutylene was heated to 75° C. after heat exchange and entered the gas phase inlet through a metering pump. The gas and liquid were fully mixed in the ultragravity reactor and a preliminary reaction was carried out. Among them, the gas-liquid ratio in the ultragravity reactor was 300:1 (v / v), the rotation speed was 1000 rpm, the operating pressure was 0.6 MPa, and the residence time was 2.5 s.

[0065] The liquid product obtained from the ultra-gravity reactor is introduced into the reaction tube through a buffer tank and a metering pump to continue the copolymerization reaction of isobutylene and maleic anhydride. The reaction pressure is 0.6 MPa, the number of reaction tubes is 10, the inner diameter of the reaction tube is 5 cm, and the reaction time is 3 h.

[0066] The obtained liquid-solid blended product was centrifuged, and then the solid phase product was washed and dried with ethanol to obtain a white isobutylene maleic anhydride copolymer powder.

[0067] Table 5 shows the changes in the operating temperature of the reaction tube and the yield of the copolymer.

[0068] Table 5

[0069] Serial number Reaction tube temperature Copolymer quality Number average molecular weight of copolymer 1 55℃ 275g 72000 2 70℃ 305g 60000 3 90℃ 302g 49000

[0070] Figure 2 This is the infrared spectrum of the copolymer obtained under the conditions of No. 1 in Example 5, 1772 cm -1 and 1851cm -1 is the C=O stretching vibration absorption peak of the anhydride, 3000cm -1 Nearby are the stretching vibration absorption peaks of methyl and methylene.

[0071] Example 6

[0072] After nitrogen was purged through the ultragravity reactor, 1.4 L of butyl acetate solution containing 3.1 g of dicarbonyl peroxide and 196 g of maleic anhydride was heated to 75° C. after heat exchange and entered the liquid phase inlet of the ultragravity reactor through a metering pump. Isobutylene was heated to 75° C. after heat exchange and entered the gas phase inlet through a metering pump. The gas and liquid were fully mixed in the ultragravity reactor and a preliminary reaction was carried out. The gas-liquid ratio in the ultragravity reactor was 300:1 (v / v), the rotation speed was 1000 rpm, the operating pressure was 0.6 MPa, and the residence time was 2.5 s.

[0073] The liquid product obtained from the ultra-gravity reactor is introduced into the reaction tube through a buffer tank and a metering pump to continue the polar copolymerization reaction of isobutylene and maleic anhydride. The reaction temperature is 70°C, the number of reaction tubes is 10, the inner diameter of the reaction tube is 5 cm, and the reaction time is 3 hours;

[0074] The obtained liquid-solid blended product was centrifuged, and then the solid phase product was washed and dried with ethanol to obtain a white isobutylene maleic anhydride copolymer powder.

[0075] Table 6 shows the changes in the operating pressure of the reaction tube and the yield of the copolymer.

[0076] Table 6

[0077] Serial number Reaction tube pressure Copolymer quality Number average molecular weight of copolymer 1 0.2Mpa 287g 52000 2 0.6Mpa 305g 60000 3 2Mpa 300g 62000

[0078] Example 7

[0079] After nitrogen was purged through the ultragravity reactor, 1.4 L of isoamyl acetate solution containing 3.1 g of azobisisobutyronitrile and 196 g of maleic anhydride was heated to 75° C. after heat exchange and entered the liquid phase inlet of the ultragravity reactor through a metering pump. Isobutylene was heated to 75° C. after heat exchange and entered the gas phase inlet through a metering pump. The gas and liquid were fully mixed in the ultragravity reactor and a preliminary reaction was carried out. Among them, the gas-liquid ratio in the ultragravity reactor was 300:1 (v / v), the rotation speed was 1000 rpm, the operating pressure was 0.6 MPa, and the residence time was 2.5 s.

[0080] The liquid product obtained from the ultra-gravity reactor is introduced into the reaction tube through a buffer tank and a metering pump to continue the polar copolymerization reaction of isobutylene and maleic anhydride. The reaction temperature is 70°C, the reaction pressure is 0.6MPa, the inner diameter of the reaction tube is 5cm, and the reaction time is 3h;

[0081] The obtained liquid-solid blended product was centrifuged, and then the solid phase product was washed and dried with ethanol to obtain a white isobutylene maleic anhydride copolymer powder.

[0082] Table 7 shows the changes in the number of reaction tubes and the yield of copolymers.

[0083] Table 7

[0084]

[0085] Example 8

[0086] After nitrogen was purged through the ultragravity reactor, 1.4 L of isoamyl acetate solution containing a certain amount of azobisisobutyronitrile and 196 g of maleic anhydride was heated to 75° C. after heat exchange and entered the liquid phase inlet of the ultragravity reactor through a metering pump. Isobutylene was heated to 75° C. after heat exchange and entered the gas phase inlet through a metering pump. The gas and liquid were fully mixed in the ultragravity reactor and a preliminary reaction was carried out. Among them, the gas-liquid ratio in the ultragravity reactor was 300:1 (v / v), the rotation speed was 1000 rpm, the operating pressure was 0.6 MPa, and the residence time was 2.5 s.

[0087] The liquid product obtained from the ultra-gravity reactor is introduced into the reaction tube through a buffer tank and a metering pump to continue the polar copolymerization reaction of isobutylene and maleic anhydride. The reaction temperature is 70°C, the reaction pressure is 0.6MPa, the number of reaction tubes is 10, the inner diameter of the reaction tube is 5cm, and the reaction time is 3h;

[0088] The obtained liquid-solid blended product was filtered and separated, and then the solid phase product was washed and dried with ethanol to obtain a white isobutylene maleic anhydride copolymer powder.

[0089] Table 8 shows the changes in the amount of initiator used in the system and the yield of the copolymer.

[0090] Table 8

[0091] Serial number Initiator quality Copolymer quality Number average molecular weight of copolymer 1 3.1g 305g 60000 2 15.4g 307g 49000 3 31g 305g 32000

[0092] Example 9

[0093] After nitrogen was purged through the ultragravity reactor, 1.4 L of isoamyl acetate solution containing 3.1 g of azobisisobutyronitrile and a certain amount of maleic anhydride was heated to 75° C. after heat exchange and entered the liquid phase inlet of the ultragravity reactor through a metering pump. Isobutylene was heated to 75° C. after heat exchange and entered the gas phase inlet through a metering pump. The gas and liquid were fully mixed in the ultragravity reactor and a preliminary reaction was carried out. Among them, the gas-liquid ratio in the ultragravity reactor was 300:1 (v / v), the rotation speed was 1000 rpm, the operating pressure was 0.6 MPa, and the residence time was 2.5 s.

[0094] The liquid product obtained from the ultra-gravity reactor is introduced into the reaction tube through a buffer tank and a metering pump to continue the polar copolymerization reaction of isobutylene and maleic anhydride. The reaction temperature is 70°C, the reaction pressure is 0.6MPa, the number of reaction tubes is 10, the inner diameter of the reaction tube is 5cm, and the reaction time is 3h;

[0095] The obtained liquid-solid blended product was filtered and separated, and then the solid phase product was washed and dried with ethanol to obtain a white isobutylene maleic anhydride copolymer powder.

[0096] Table 9 shows the changes in the ratio of maleic anhydride to solvent in the system and the yield of the copolymer.

[0097] Table 9

[0098] Serial number Ratio of maleic anhydride to solution Copolymer quality Number average molecular weight of copolymer 1 5％ 228g 48000 2 14％ 305g 60000 3 22％ 297g 69000

[0099] Comparative Example 1

[0100] This comparative example was carried out under the experimental condition of supergravity speed of 0, that is, 1.4L isoamyl acetate solution containing 3.1g of azobisisobutyronitrile and 196g of maleic anhydride was heated to 60°C after heat exchange, and isobutylene was directly introduced into the reaction tube through a buffer tank and a metering pump to carry out polar copolymerization of isobutylene and maleic anhydride, the reaction temperature was 60°C, the reaction pressure was 0.6MPa, the number of reaction tubes was 10, the inner diameter of the reaction tube was 5cm, and the reaction time was 3h;

[0101] The obtained liquid-solid blended product was separated by filtration, and then the solid phase product was washed with ethanol and dried to obtain 173 g of white isobutylene maleic anhydride copolymer powder.

[0102] Compared with the conditions under supergravity (gas-liquid ratio of 300:1 (v / v), operating pressure of 0.6 MPa, rotation speed of 1000 rpm), the powder yield of isobutylene-maleic anhydride copolymer is reduced at the same reaction time.

[0103] Comparative Example 2

[0104] This comparative example was conducted under the experimental condition of supergravity speed of 0, that is, 1.4L isoamyl acetate solution containing 3.1g of azobisisobutyronitrile and 196g of maleic anhydride was heated to 60°C after heat exchange, and isobutylene was directly introduced into the reaction tube through a buffer tank and a metering pump to carry out polar copolymerization of isobutylene and maleic anhydride, the reaction temperature was 60°C, the reaction pressure was 0.6MPa, the number of reaction tubes was 10, and the inner diameter of the reaction tube was 5cm;

[0105] The obtained liquid-solid blended product was filtered and separated, and then the solid phase product was washed and dried with ethanol to obtain a white isobutylene maleic anhydride copolymer powder.

[0106] Table 10 shows the reaction time of changing the reaction tube and the yield of the copolymer.

[0107] Table 10

[0108] Serial number Reaction time of the reaction tube Copolymer quality 1 5h 272g 2 6h 294g 3 7h 303g

[0109] Compared with the conditions under supergravity (gas-liquid ratio of 300:1 (v / v), operating pressure of 0.6 MPa, rotation speed of 1000 rpm), if the isobutylene maleic anhydride copolymer powder with similar quality is obtained, the reaction time of the reaction tube needs to be increased by more than 1 times.

[0110] Comparative Example 3

[0111] In this comparative example, after nitrogen was purged through the supergravity reactor, 1.4 L of isoamyl acetate solution containing 3.1 g of azobisisobutyronitrile and 196 g of maleic anhydride was subjected to heat exchange to 60° C. and entered the liquid phase inlet of the supergravity reactor through a metering pump. Isobutylene was subjected to heat exchange to a temperature of 60° C. and entered the gas phase inlet through a metering pump. The gas and liquid were fully mixed in the supergravity reactor and a preliminary reaction was carried out; wherein the gas-liquid ratio in the supergravity reactor was 300:1 (v / v), the rotation speed was 1000 rpm, the operating pressure was 0.6 MPa, and the residence time was 2.5 s.

[0112] The liquid product obtained from the ultra-gravity reactor is introduced into the reactor through a buffer tank and a metering pump to continue the polar copolymerization reaction of isobutylene and maleic anhydride. The reaction temperature is 60°C, the reaction pressure is 0.6MPa, and the reaction time is 3h.

[0113] The obtained liquid-solid blended product was filtered and separated, and then the solid phase product was washed and dried with ethanol to obtain a white isobutylene maleic anhydride copolymer powder.

[0114] Table 11 shows the yield of isobutylene maleic anhydride copolymer under the same experimental conditions and the same reaction time in the reaction tube and the reaction kettle.

[0115] Table 11

[0116] Yield of isobutylene maleic anhydride copolymer Reaction tube 305g Reactor 290g

[0117] Compared with the reactor, the yield of isobutylene maleic anhydride copolymer powder will be increased under the same experimental conditions and the same reaction time.

[0118] Of course, the present invention may have many other embodiments. Without departing from the spirit and essence of the present invention, technicians familiar with the field may make various corresponding changes and deformations based on the present invention, but these corresponding changes and deformations should all fall within the scope of protection of the claims of the present invention.

Claims

1. A method for copolymerizing isobutylene and maleic anhydride, characterized in that: The following steps are involved: S1, introducing isobutylene and a maleic anhydride solution containing an initiator into a supergravity reactor to mix the isobutylene and the maleic anhydride and perform a pre-reaction; S2, passing the liquid product obtained in step S1 into a reaction tube reactor to continue the reaction; The rotation speed of the supergravity reactor in step S1 is 100 rpm to 2000 rpm; In step S1, the volume ratio of isobutylene to the maleic anhydride solution containing the initiator is 50-500:1; In step S1, the pre-reaction time is 1-4 s, the pressure is 0.1-2 MPa, and the reaction temperature is 55-100° C.; In step S2, the reaction time is 1-4 hours, the pressure is 0.2-2 MPa, and the reaction temperature is 50-100° C.; The reaction tube reactor comprises a shell, with a liquid phase inlet and a liquid phase outlet respectively provided at two ends of the shell, a plurality of hollow flow guide tubes are provided in the shell, one end of the plurality of hollow flow guide tubes is connected to the liquid phase inlet, and the other end is connected to the liquid phase outlet.

2. The method for copolymerizing isobutylene and maleic anhydride according to claim 1, characterized in that: The rotation speed of the supergravity reactor in step S1 is 300 rpm to 2000 rpm.

3. The method for copolymerizing isobutylene and maleic anhydride according to claim 1, characterized in that: The weight ratio of isobutylene to maleic anhydride is 0.2-5:

1.

4. The method for copolymerizing isobutylene and maleic anhydride according to claim 1, characterized in that: The weight ratio of isobutylene to maleic anhydride is 0.5-3:

1.

5. The method for copolymerizing isobutylene and maleic anhydride according to claim 1, characterized in that: The amount of the initiator is 1%-20% of the weight of maleic anhydride.

6. The method for copolymerizing isobutylene and maleic anhydride according to claim 1, characterized in that: The concentration of maleic anhydride in the maleic anhydride solution containing the initiator is 3wt% to 25wt%, and the solvent for dissolving maleic anhydride and the initiator is at least one of organic acid alkyl ester, alkane and aromatic hydrocarbon.

7. The method for copolymerizing isobutylene and maleic anhydride according to claim 1, characterized in that: The initiator is a thermal decomposition type initiator, including at least one of dibenzoyl peroxide, diisopropyl peroxide, di-tert-butyl peroxide, dodecyl peroxide, tert-butyl perbenzoate, diisopropyl peroxydicarbonate, dicarbonyl peroxide, azobisisobutyronitrile and azobisisoheptylonitrile.

8. The method for copolymerizing isobutylene and maleic anhydride according to claim 1, characterized in that: The inner diameter of the guide tube is 3-6 cm, the number of the guide tubes is 3-10, and the length is 8-16 cm.

9. The method for copolymerizing isobutylene and maleic anhydride according to claim 8, characterized in that: The length of the flow guide tube is 10 cm.

10. The method for copolymerizing isobutylene and maleic anhydride according to claim 6, characterized in that: The reaction tube reactor is provided with a pressure control valve, and the pressure control range is 0-10MPa.

11. The method for copolymerizing isobutylene and maleic anhydride according to claim 1, characterized in that: After step S2 is completed, a separation step is also included, in which the liquid-solid blended product obtained in step S2 is separated, and then the solid phase product is washed and dried.

12. The method for copolymerizing isobutylene and maleic anhydride according to claim 11, characterized in that: The separation method is filtration separation or centrifugal separation, the liquid phase product after separation is recycled, the washing liquid used for washing is an alcohol liquid, and the drying method is drying.

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