Precipitation polymerization method of Fischer-Tropsch synthesis product and functionalized cross-linked copolymer microspheres prepared by precipitation polymerization method

Abstract

The invention relates to a precipitation polymerization method of a Fischer-Tropsch synthesis product and functionalized cross-linked copolymer microspheres prepared by the precipitation polymerization method. The precipitation polymerization method comprises the following steps: carrying out precipitation polymerization on a reaction system containing a Fischer-Tropsch synthesis product, an electron accepting monomer, a cross-linking agent, an initiator and a solvent; a cross-linking group of the cross-linking agent is a group with a carbon-carbon double bond; the Fischer-Tropsch synthesis product comprises an electron donating monomer. The precipitation polymerization method provided by the invention has the characteristics of simple process, easy product separation and low cost, and provides an effective way for high-value utilization of Fischer-Tropsch synthesis products.

Description

TECHNICAL FIELD

[0001] The present application belongs to the field of polymer synthesis, and particularly relates to a precipitation polymerization method of Fischer-Tropsch synthesis products and functionalized crosslinked copolymer microspheres prepared therefrom. BACKGROUND

[0002] Fischer-Tropsch synthesis is a technology for producing hydrocarbons from synthesis gas (CO and H2). The technology was originally used to synthesize liquid fuels from synthesis gas produced by coal gasification as a substitute for petroleum. Today, the source of synthesis gas for Fischer-Tropsch synthesis has expanded to coal, natural gas, biomass, etc., and is expected to become a sustainable source of hydrocarbons in the future.

[0003] Fischer-Tropsch synthesis products have a wide range of carbon number distribution, and common fractions include naphtha fraction, heavy oil fraction, and heavy wax, etc. The composition of Fischer-Tropsch synthesis products is complex, mainly including alpha-olefins, n-alkanes and oxygen-containing compounds, and has the advantages of no sulfur, no nitrogen and low aromatic hydrocarbons. After hydroprocessing and separation, Fischer-Tropsch synthesis products can be used to produce gasoline blending oil and high-cetane diesel, etc. However, the above-mentioned processing methods have low value.

[0004] Currently, the research on high-value utilization of Fischer-Tropsch synthesis products mainly focuses on separating and extracting individual alpha-olefins. The separated alpha-olefins can be used as comonomers for ethylene (for example, 1-hexene, 1-octene), or for producing linear alkyl alcohols, sulfonates and other chemicals. In addition, studies have shown that single carbon number alpha-olefins can also be free-radically copolymerized with maleic anhydride, thereby converting them into polymer resources.

[0005] Patent Document 1 and Patent Document 2 disclose a method and device for separating 1-heptene and 1-octene from Fischer-Tropsch synthesis oil wash naphtha. The oil wash naphtha is subjected to rectification, deoxygenation, etherification, and rectification to obtain 1-heptene and 1-octene.

[0006] Patent Document 3 and Patent Document 4 respectively disclose a method and device for separating and purifying 1-decene and 1-dodecene from Fischer-Tropsch synthesis stable heavy oil. The stable heavy oil is subjected to narrow fraction cutting and then subjected to a series of reactions to obtain 1-decene and 1-dodecene.

[0007] In Non-Patent Document 1 to Non-Patent Document 4, 1-hexene-maleic anhydride, 1-octene-maleic anhydride, 1-dodecene-maleic anhydride, 1-tetradecene-maleic anhydride, and 1-octadecene-maleic anhydride copolymers are prepared by using benzoyl peroxide, azobisisobutyronitrile and other initiators, selecting toluene, xylene, acetone, dioxane and other solvents, and using methanol, n-hexane and other precipitants.

[0008] Patent document 5 introduces the preparation of α-olefin-maleic anhydride copolymer by free radical polymerization, using dibenzoyl peroxide, azobisisobutyronitrile and other initiators, selecting a mixture of organic acid alkyl ester and hexane as the solvent, reacting at 60-95 ℃ for 2-24 hours, to prepare 1-octene-maleic anhydride, 1-decene-maleic anhydride, 1-dodecene-maleic anhydride, 1-tetradecene-maleic anhydride copolymer.

[0009] Patent document 6 and non-patent document 5 disclose a method of directly copolymerizing unseparated Fischer-Tropsch synthesis products with electron-withdrawing functional monomers such as maleic anhydride. This method avoids the problem of α-olefins being difficult to self-polymerize by free radical polymerization due to the allyl structure, and can obtain a functional copolymer with high yield.

[0010] Patent document 7 discloses a method of copolymerizing Fischer-Tropsch synthesis products with electron-withdrawing functional monomers and low-carbon-number olefins. This method uses self-stabilizing precipitation polymerization, and the separation of the polymerization product can be achieved by simple treatment, and the solvent in the supernatant obtained by separation can be recycled.

[0011] Citation documents

[0012] Patent documents:

[0013] Patent document 1: CN 118388311 A;

[0014] Patent document 2: CN 114805005 A;

[0015] Patent document 3: CN 114685235 A;

[0016] Patent document 4: CN 114644543 A;

[0017] Patent document 5: CN 114426639 A;

[0018] Patent document 6: CN 117417481 A;

[0019] Patent document 7: CN 119285852 A.

[0020] Non-patent documents:

[0021] Non-patent literature 1: Nifant'ev I. E et al., "Copolymers of Maleic Anhydride and Methylene Alkanes: Synthesis, Modification, and Pour Point Depressant Properties", Polymer Science, Series B, 2018, 60(4): 469-480;

[0022] Non-patent literature 2: Demircan D et al., "Preparation of Poly(MA-alt-a-olefin-C6, 8, 12, 18) / Silica Nanohybrids via in situ generated nanofillers for use as a dual function organonanofiller", Journal of Chemical Sciences, 2015, 127(11): 1993-2003;

[0023] Non-patent literature 3: Davies M C et al., "Molar mass determination of poly(octadecene-alt-maleic anhydride) copolymers by size exclusion chromatography and dilute solution viscometry", Polymer, 2002, 43(15): 4311-4314;

[0024] Non-patent literature 4: Chen Y et al., "A novel hyper-cross-linked polymer for high-efficient fluid-loss control in oil-based drilling fluid", Colloids and Surfaces A Physicochemical and Engineering Aspects, 2021, 626: 127004;

[0025] Non-patent document 5: Zhang X et al., "Unlock the potential of mixed olefins from the Fischer-Tropsch process: Direct synthesis of functional copolymers without pre-separation", Chemical Engineering Journal, 2025, 514: 163218. SUMMARY

[0026] PROBLEMS TO BE SOLVED BY THE INVENTION

[0027] In the methods of patent document 1 to patent document 4, the α-olefins in the Fischer-Tropsch synthesis product are separated first and then utilized. However, the method is complicated and has high cost.

[0028] In the methods of patent document 5, patent document 6 and non-patent document 1 to non-patent document 5, the alternating copolymer of α-olefin and maleic anhydride is obtained by copolymerization. However, the polymerization methods involved are all solution polymerization, and the product is difficult to separate, and a large amount of precipitator must be added for separation.

[0029] In the method of patent document 7, the copolymer of α-olefin, low-carbon olefin and maleic anhydride is synthesized by self-stabilizing precipitation polymerization, and the polymer product can be separated without precipitator. However, due to the need to add low-carbon olefin, the amount of α-olefin is limited, and due to the need to use gaseous olefin, the process is complicated and difficult.

[0030] In addition, the α-olefin-maleic anhydride copolymer prepared by the free radical polymerization means mentioned in the above documents has the problem of low molecular weight, which limits the application range of the copolymer to a certain extent.

[0031] The problem to be solved by the present application is to provide a method for efficient and high-value utilization of Fischer-Tropsch synthesis product with simple process and low cost.

[0032] SOLUTION TO THE PROBLEM

[0033] The present inventors found in the research that a small amount of crosslinking agent is added to the polymerization system of Fischer-Tropsch synthesis product and electron-accepting monomer, and precipitation polymerization can be realized, thereby completing the present application.

[0034] Specifically, the present application solves the problems of the present application by the following solutions.

[0035] [1] A precipitation polymerization method, comprising the following steps:

[0036] subjecting a reaction system containing a Fischer-Tropsch synthesis product, an electron-accepting monomer, a crosslinking agent, an initiator, and a solvent to precipitation polymerization;

[0037] the crosslinking group of the crosslinking agent is a group having a carbon-carbon double bond;

[0038] the Fischer-Tropsch synthesis product contains an electron-donating monomer.

[0039] [2] The precipitation polymerization method according to [1], wherein

[0040] the electron-accepting monomer is one or a combination of two or more selected from the group consisting of maleic anhydride, maleimide, itaconic anhydride, and derivatives thereof;

[0041] the Fischer-Tropsch synthesis product is Fischer-Tropsch synthesis oil and / or Fischer-Tropsch synthesis wax;

[0042] the crosslinking agent has 2 to 6 crosslinking groups, each crosslinking group being independently selected from the group consisting of alkenyl, (meth)acryloyl, maleimide group;

[0043] the initiator is one or more selected from the group consisting of azo compound initiators and peroxide initiators;

[0044] the solvent is an organic solvent.

[0045] [3] The precipitation polymerization method according to [2], wherein

[0046] the electron-accepting monomer is one or a combination of two or more selected from the group consisting of maleic anhydride, itaconic anhydride, maleimide, N-phenylmaleimide, N-methylmaleimide, N-ethylmaleimide, N-(1-naphthyl)maleimide;

[0047] the Fischer-Tropsch synthesis oil is Fischer-Tropsch synthesis oil stone naphtha and / or Fischer-Tropsch synthesis stable heavy oil; the content of the electron-donating monomer in the Fischer-Tropsch synthesis product is 1 to 70 mass%; the electron-donating monomer is preferably one or a combination of two or more selected from the group consisting of alkenes having 4 to 40 carbon atoms, preferably α-olefins;

[0048] the crosslinking agent has 2 to 4 crosslinking groups; each crosslinking group is independently selected from the group consisting of vinyl, vinylidene (-CH=CH-), allyl, conjugated diene, (meth)acrylate, (meth)acrylamide, maleimide group;

[0049] the solvent is one or a combination of two or more selected from the group consisting of hydrocarbon solvents, ketone solvents, carboxylate solvents, and ether solvents;

[0050] the azo compound initiator is azobisisobutyronitrile, azobisisoheptyl nitrile;

[0051] The peroxide initiator is dibenzoyl peroxide, dicumyl peroxide, ditert-butyl peroxide, dilauryl peroxide, tert-butyl peroxybenzoate, diisopropyl peroxydicarbonate, dicyclohexyl peroxydicarbonate.

[0052] [4]. The precipitation polymerization method according to any one of [1] to [3], wherein the crosslinking agent is one or more selected from the group consisting of a polyene, an alkenyl ether, a polyfunctional (meth)acrylate, a polyfunctional (meth)acrylamide, a bismaleimide, an alkenyl (meth)acrylate, and a polyfunctional allyl ester.

[0053] [5]. The precipitation polymerization method according to any one of [1] to [3], wherein,

[0054] The total concentration of the electron-donating monomer and the electron-accepting monomer in the reaction system is 5 to 75 mass %;

[0055] The mass fraction of the crosslinking agent is 0.1 to 45 mass %, preferably 0.5 to 42 mass %, and more preferably 1 to 38 mass %, based on the total mass of the electron-donating monomer, the electron-accepting monomer, and the crosslinking agent;

[0056] The mass ratio of the electron-accepting monomer to the Fischer-Tropsch synthesis product is 1:30 to 5:1;

[0057] The amount of the initiator is 0.05 to 10 mass %, based on the total mass of the electron-accepting monomer, the electron-donating monomer, and the crosslinking agent.

[0058] [6]. The precipitation polymerization method according to any one of [1] to [3], wherein the electron-accepting monomer and the initiator are mixed separately in the solvent, and then the Fischer-Tropsch synthesis product and the crosslinking agent are added, and then an inert gas is introduced into the system, and then the reaction system is heated to a polymerization temperature to perform precipitation polymerization.

[0059] [7]. The precipitation polymerization method according to any one of [1] to [3], wherein the precipitation polymerization is performed in an inert gas, the polymerization temperature is 50 to 120°C, and the polymerization time is 1 to 24 hours.

[0060] [8]. The precipitation polymerization method according to any one of [1] to [3], further comprising a step of post-treating the reaction system after the precipitation polymerization, the post-treatment preferably including one or a combination of two or more of solid-liquid separation, washing, or drying.

[0061] [9]. A copolymer obtained by the precipitation polymerization method according to any one of [1] to [8].

[0062] [10. The copolymer according to [9], wherein the copolymer is a copolymer microsphere, the number average particle diameter is 0.1-10 μm, the particle diameter distribution coefficient is 1.005-1.500, and the gel content is 5-100 mass%.

[0063] Effects of the Invention

[0064] The precipitation polymerization method of the Fischer-Tropsch synthesis product of the present application has the characteristics of simple process, easy separation of product and low cost, and provides an effective way for high value utilization of Fischer-Tropsch synthesis products.

[0065] Specifically, the present application has the following beneficial effects:

[0066] (1) The process of the present application is simple, and only a small amount of crosslinking agent needs to be added to realize precipitation polymerization. After polymerization, simple treatment can realize solid-liquid separation, and the solvent in the supernatant obtained by separation can be recycled, and the remaining is unreacted long-chain alkane, which is suitable for industrial production.

[0067] (2) The method of the present application can directly use the Fischer-Tropsch synthesis product or its fraction without separation as raw material, without refining and separation, greatly reducing the cost;

[0068] (3) The functional copolymer prepared by the method of the present application is in the form of microspheres, and by adjusting the type and amount of crosslinking agent, monomer ratio and type of Fischer-Tropsch synthesis product, copolymer products with different gel contents and different hydrophilic and hydrophobic properties can be obtained.

[0069] (4) The copolymer prepared by the method of the present application has a high content of functional groups, which can be further modified for functionalization, widening the application range of functional copolymers and effectively utilizing Fischer-Tropsch synthesis product resources. BRIEF DESCRIPTION OF DRAWINGS

[0070] Fig. 1 SEM photograph of the copolymer microspheres obtained in Example 1;

[0071] Fig. 2 SEM photograph of the copolymer microspheres obtained in Example 3;

[0072] Fig. 3 SEM photograph of the copolymer microspheres obtained in Example 5. DETAILED DESCRIPTION

[0073] Hereinafter, the content of the present application will be described in detail. The description of the technical features described below is based on representative embodiments, specific examples of the present application, but the present application is not limited to these embodiments, specific examples.

[0074] TERMS AND DEFINITIONS

[0075] In the present specification, "Fischer-Tropsch synthesis product" means a product obtained by Fischer-Tropsch synthesis.

[0076] In the present specification, "particle diameter" means a number average particle diameter of the described particles, which can be obtained by the method described in the Examples section.

[0077] In the present specification, "electron-accepting monomer" means a monomer having an electron- withdrawing group on a carbon-carbon double bond participating in polymerization.

[0078] In the present specification, "electron-donating monomer" means a monomer having an electron-donating group on a carbon-carbon double bond participating in polymerization.

[0079] In the present specification, "alkyl group" means a linear, branched, or cyclic alkyl group, unless otherwise explicitly stated.

[0080] In the present specification, a numerical range expressed using "numerical value A to numerical value B" or "numerical value A - numerical value B" means a range including the end point numerical values A, B.

[0081] In the present specification, a numerical range expressed using "above" or "below" means a numerical range including the present number.

[0082] In the present specification, the meaning expressed using "may" includes both the meaning of performing a certain process and the meaning of not performing a certain process.

[0083] In the present specification, "optionally" or "optional" means that a certain substance, component, execution of a step, application of a condition, and the like is used or not used.

[0084] In the present specification, the unit names used are international standard unit names, and if not specifically stated, "%" used means a percentage by weight or mass.

[0085] In the present specification, the "preferred embodiments", "embodiments", and the like referred to mean that the particular element (e.g., feature, structure, property, and / or characteristic) described in relation to the embodiment is included in at least one embodiment described herein, and can or can not be present in other embodiments. In addition, it should be understood that the described elements can be combined in any suitable manner in various embodiments.

[0086] <Precipitation polymerization method>

[0087] An object of the present application is to provide a precipitation polymerization method including the steps of:

[0088] causing a reaction system containing a Fischer-Tropsch synthesis product, an electron-accepting monomer, a crosslinking agent, an initiator, and a solvent to undergo precipitation polymerization;

[0089] The crosslinking group of the crosslinking agent is a group having a carbon-carbon double bond;

[0090] The Fischer-Tropsch synthesis product contains an electron-donating monomer.

[0091] In previous studies, the copolymerization of the Fischer-Tropsch synthesis product and the electron-accepting monomer can only be carried out by solution polymerization, and the polymeric product must be separated by using an alkyl alcohol as a precipitant. Although the self-stabilizing precipitation polymerization of the Fischer-Tropsch synthesis product and the electron-accepting monomer can be achieved by adding a low-carbon number olefin, the amount of the low-carbon number olefin added is often large, and the low-carbon number olefin is a gas, which requires the polymerization reaction to be carried out under a certain pressure, and has a high requirement on the equipment. In the precipitation polymerization method of the present application, only a small amount of crosslinking agent needs to be added, and crosslinked copolymer microspheres can be obtained. Further, by adjusting the type and amount of the crosslinking agent, the crosslinking degree (gel content) of the obtained microspheres can be controlled.

[0092] In the method of the present application, the crosslinking agent and the α-olefin participate in polymerization simultaneously, and an alternating or random copolymer of the electron-donating monomer and the electron-accepting monomer is obtained, and the precipitation polymerization of the Fischer-Tropsch synthesis product and the electron-accepting monomer is realized through the crosslinking reaction.

[0093] The method of the present application has the characteristics of simplicity and low cost, and provides a solution to the problem of high-value utilization of α-olefin in the Fischer-Tropsch synthesis product.

[0094] The following describes in detail various aspects of the precipitation polymerization method of the present application.

[0095] <Reaction system>

[0096] The reaction system of the precipitation polymerization method of the present application comprises a Fischer-Tropsch synthesis product, an electron-accepting monomer, a crosslinking agent, an initiator and a solvent.

[0097] The Fischer-Tropsch synthesis product is the product of the Fischer-Tropsch synthesis technology, and its components include n-alkanes, n-olefins, branched alkanes, branched olefins and n-alcohols, etc., among which n-alkanes and n-olefins are the main components, and the olefin components are mostly α-olefins.

[0098] The present application does not have special restrictions on the composition of the Fischer-Tropsch synthesis product, as long as it contains an electron-donating monomer that can copolymerize with the electron-accepting monomer, which can be specifically selected by those skilled in the art as needed. The Fischer-Tropsch synthesis product can be a Fischer-Tropsch synthesis oil product without separation, can also be different fractions of the Fischer-Tropsch synthesis oil product, and can also be a Fischer-Tropsch synthesis wax, as long as it contains an electron-donating monomer.

[0099] Preferably, the content of the electron-donating monomer in the Fischer-Tropsch synthesis product is 1-70 mass%, preferably 5-65 mass%, more preferably 20-65 mass%, for example, 30 mass%, 40 mass%, 50 mass%, 60 mass% and the like.

[0100] Preferably, the electron-donating monomer is one or more combinations selected from alkenes having 4 to 40 carbon atoms, preferably α-olefins, more preferably selected from 1-butene, 1-pentene, 1-hexene, 1-heptene, 1-octene, 1-nonene, 1-decene, 1-undecene, 1-dodecene, 1-tetracene, 1-tetradecene, 1-pentadene, 1-hexadecene, 1-heptadecene, 1-heptadecene, 1-heptadecene, 1-octadecene, 1-nonadene, 1-eicosene, 1-timodec ...

[0101] In some embodiments, the Fischer-Tropsch synthesis products are Fischer-Tropsch synthetic oils and / or Fischer-Tropsch synthetic waxes, wherein the Fischer-Tropsch synthetic oils are preferably Fischer-Tropsch synthetic oil-washed naphtha and / or Fischer-Tropsch synthetic stabilized heavy oils. The Fischer-Tropsch synthetic oil-washed naphtha primarily contains C4 to C14 components, including about 60-70% by mass of α-olefins. The Fischer-Tropsch synthetic stabilized heavy oil primarily contains C8 to C30 components, including about 55-65% by mass of α-olefins. The Fischer-Tropsch synthetic (heavy) wax primarily contains components with a higher carbon number (C30 and above), including about 1-10% by mass of α-olefins.

[0102] In this invention, components other than α-olefins in the Fischer-Tropsch synthesis products, such as n-alkanes, branched alkanes and alkenes, and other components, can serve as the reaction medium. These media can also be separated after polymerization and used as products such as gasoline and diesel.

[0103] In this invention, an electron-accepting monomer is polymerized with an electron-donating monomer from a Fischer-Tropsch synthesis product to obtain a functional copolymer with functional groups. Furthermore, the functional groups can be anhydride groups, imide groups, etc.

[0104] In one embodiment, the electron-accepting monomer is one or more combinations selected from maleic anhydride, maleimide, itaconic anhydride, and their derivatives.

[0105] Preferably, the electron-accepting monomer is one or a combination of two or more selected from maleic anhydride, itaconic anhydride, maleimide, N-phenylmaleimide, N-methylmaleimide, N-ethylmaleimide, and N-(1-naphthyl)maleimide.

[0106] In this invention, a crosslinking agent is added to participate in the copolymerization reaction of electron-donating and electron-accepting monomers in the Fischer-Tropsch synthesis product, thereby obtaining a crosslinked copolymer (microspheres).

[0107] The crosslinking groups in the crosslinking agent used in this invention are groups having carbon-carbon double bonds, preferably selected from one or more of alkenyl, (meth)acryloyl, and maleimide. These groups can be end groups of the crosslinking agent or non-end groups, and more preferably selected from one or more of vinyl, vinylidene (-CH=CH-), allyl, conjugated dienyl, (meth)acrylate, (meth)acrylamide, and maleimide.

[0108] The crosslinking agent used in this invention preferably has 2 to 6 (e.g., 2, 3, 4, 5, or 6) crosslinking groups, more preferably 2 to 4 crosslinking groups, more preferably 2 or 3 crosslinking groups, and most preferably 2 crosslinking groups. By keeping the number of crosslinking groups within the above range, premature polymer precipitation (excessive crosslinking density) can be avoided while achieving precipitation polymerization.

[0109] In some embodiments, the crosslinking agent is one or more selected from polyolefins, alkenyl ethers, polyfunctional (meth)acrylates, polyfunctional (meth)acrylamides, bismaleimide, (meth)acrylate alkenyl esters, and polyfunctional allyl esters.

[0110] In this invention, the "polyene" used as a crosslinking agent refers to a hydrocarbon having multiple (two or more, preferably two or three) carbon-carbon double bonds. The polyene can be an aliphatic polyene or an aromatic polyene.

[0111] The aliphatic polyenes can be conjugated or non-conjugated. More preferably, they are chain dienes with 4 to 22 carbon atoms (preferably 4 to 16, more preferably 4 to 12, even more preferably 4 to 8 carbon atoms), monocyclic dienes with 4 to 22 carbon atoms (preferably 5 to 16, more preferably 5 to 12, even more preferably 5 to 8 carbon atoms), and bicyclic dienes with 8 to 20 carbon atoms (preferably 8 to 16, even more preferably 8 to 12). A "monocyclic diene" refers to a compound having one cyclic diene group in its molecule, a "bicyclic diene" refers to a compound containing two cyclic diene groups in its molecule, and a "cyclic diene group" refers to a group having two carbon-carbon double bonds in a ring.

[0112] Examples of cyclodienes include, but are not limited to, 1,3-butadiene, 1,3-pentadiene, isoprene, 1,3-hexadiene, 1,4-pentadiene, 1,4-hexadiene, and 1,5-hexadiene. Examples of monocyclic dienes include, but are not limited to, cyclopentadiene, methylcyclopentadiene, 1,3-cyclohexadiene, 1,4-cyclohexadiene, and 1,5-cyclooctadiene. The cyclodiene group in a dicyclic diene can be cyclopentadienyl, and examples include, but are not limited to, dicyclopentadiene, methyldicyclopentadiene (e.g., 2-methyldicyclopentadiene, 5-methyldicyclopentadiene), ethyldicyclopentadiene (e.g., 2-ethyldicyclopentadiene), and 5,5-dimethyldicyclopentadiene.

[0113] Aromatic polyenes are, for example, aromatic compounds having at least two vinyl substituents, including but not limited to divinylbenzene, divinyltoluene, trivinylbenzene, and divinylnaphthalene.

[0114] In this invention, the "alkenyl ether" used as a crosslinking agent refers to an ether having two or more alkenyl groups, preferably allyl ether or vinyl ether. The allyl ether is preferably an allyl ether of a polyol (an alcohol having at least two hydroxyl groups), and the vinyl ether is preferably a vinyl ether of a polyol (an alcohol having at least two hydroxyl groups). The polyol may, for example, have 2 to 6, preferably 2 to 4 hydroxyl groups, and is further preferably selected from diols having 2 to 6 carbon atoms (e.g., ethylene glycol, propylene glycol, butanediol, pentanediol, and hexanediol), glycerol, trimethylolpropane, and pentaerythritol, etc.

[0115] Examples of allyl ethers used as crosslinking agents in this invention include, but are not limited to, diallyl ether, ethylene glycol diallyl ether, diethylene glycol diallyl ether, triethylene glycol diallyl ether, trimethylolpropane diallyl ether, pentaerythritol triallyl ether, bisphenol A diallyl ether, etc.

[0116] Examples of vinyl ethers used as crosslinking agents in this invention include, but are not limited to, divinyl ether, ethylene glycol divinyl ether, diethylene glycol divinyl ether, triethylene glycol divinyl ether, 1,4-divinoxybenzene, etc.

[0117] In this invention, the "polyfunctional (meth)acrylate" used as a crosslinking agent refers to a compound having at least two (e.g., two to six, or even three, four, or five) (meth)acrylate groups. Preferably, the polyfunctional (meth)acrylate is a (meth)acrylate of a polyol (an alcohol having at least two hydroxyl groups). The polyol may, for example, have 2 to six, preferably 2 to four, hydroxyl groups, and is further preferably selected from diols having 2 to six carbon atoms (e.g., ethylene glycol, propylene glycol, butanediol, pentanediol, and hexanediol), glycerol, trimethylolpropane, pentaerythritol, ethylene glycol oligomers, propylene glycol oligomers, etc.

[0118] Examples of polyfunctional (meth)acrylates include, but are not limited to, ethylene glycol dimethacrylate, 1,2-propanediol dimethacrylate, butanediol dimethacrylate (e.g., butane-1,4-diol dimethacrylate), hexanediol dimethacrylate, neopentyl glycol dimethacrylate, 3-methylpentyl glycol dimethacrylate, diethylene glycol dimethacrylate, triethylene glycol dimethacrylate, tetraethylene glycol dimethacrylate, etc.

[0119] In this specification, "polyfunctional (meth)acrylamide" refers to a compound having at least two (e.g., two to six, or even three, four, or five) (meth)acrylamide groups. Examples include, but are not limited to, N,N'-methylenebis(meth)acrylamide, N,N'-ethylenebis(meth)acrylamide, and N,N'-(1,6-hexylene)bis(meth)acrylamide.

[0120] In this invention, "bismaleimide" as a crosslinking agent refers to a compound having two maleimide groups, examples of which include, but are not limited to, N,N'-(4,4'-methylenediphenyl)bismaleimide, N,N'-(4-methyl-1,3-phenylene)bismaleimide, 2,2'-bis[4-(4-maleimidephenoxy)phenyl]propane, N,N'-m-phenylenebismaleimide, N,N'-(1,4-phenylene)bismaleimide, and N,N'-(4-methyl-1,3-phenylene)bismaleimide. Phenyl)bismaleimide, 1,2-bis(maleimide)ethane, 1,3-bis(maleimide)propane, 1,4-bis(maleimide)butane, bis[4-(3-maleimidephenoxy)phenyl]sulfone, 1,4-bis(4-maleimidephenoxy)benzene, 1,4-bis(3-maleimidephenoxy)benzene, 3,4'-diphenyl ether bismaleimide, 4,4'-diphenyl ether bismaleimide, etc.

[0121] Examples of (meth)acrylate alkenyl esters include, but are not limited to, (meth)acrylate vinyl esters, (meth)acrylate allyl esters, etc.

[0122] In this invention, the "polyfunctional allyl ester" used as a crosslinking agent refers to an allyl ester of a polybasic acid (a compound having at least two (e.g., two to six, or even three, four, or five) carboxyl groups), examples of which include, but are not limited to, diallyl maleate, diallyl fumarate, diallyl succinate, diallyl adipate, triallyl isocyanurate, triallyl cyanurate, diallyl phthalate, diallyl isophthalate, diallyl terephthalate, etc.

[0123] In a preferred embodiment, the crosslinking agent is one or more selected from polyolefins, polyfunctional allyl esters, and polyfunctional acrylates. More preferably, the crosslinking agent is one or more selected from diallyl maleate, dicyclopentadiene, divinylbenzene, diallyl phthalate, triallyl isocyanurate, 1,4-butanediol diacrylate, and diallyl terephthalate.

[0124] In some embodiments, the total mass concentration of electron-donating and electron-accepting monomers in the reaction system is 5-75%, preferably 10-60%, for example: 15%, 20%, 25%, 30%, 35%, 40%, 45%, 50%, 55%, 65%, etc. By keeping the total mass concentration of electron-donating and electron-accepting monomers within the above range, the polymerization reaction can proceed more effectively.

[0125] In some embodiments, the mass ratio of the electron-receiving monomer to the Fischer-Tropsch synthesis product is 1:30 to 5:1, preferably 1:30 to 3:1, for example: 1:25, 1:20, 1:15, 1:10, 1:5, 1:3, 1:2, 1:1, 2:1, 3:1, 4:1, etc.

[0126] In some embodiments, the content of the crosslinking agent is 0.1-45% based on the total mass of the electron-donating monomer, electron-accepting monomer and crosslinking agent as 100%, preferably 0.5-42%, more preferably 1-38%, for example 1.5%, 2%, 5%, 10%, 15%, 20%, 25%, 30%, 35%, etc.

[0127] In this invention, an initiator is used to polymerize the electron-accepting monomer, the electron-donating monomer in the Fischer-Tropsch synthesis product, and the crosslinking agent. In one embodiment, the initiator is one or more selected from azo compound initiators and peroxide initiators. Preferably, the peroxide initiator is benzoyl peroxide, dicumyl peroxide, di-tert-butyl peroxide, dodecyl peroxide, tert-butyl peroxide, diisopropyl peroxide, dicyclohexyl peroxide, etc.; the azo compound initiator is azobisisobutyronitrile, azobisisoheptanenitrile, etc.

[0128] In one embodiment, the initiator content is 0.05-10 wt%, preferably 0.5-5 wt%, more preferably 1-5 wt%, based on the total mass of the electron-accepting monomer, the electron-donating monomer in the Fischer-Tropsch synthesis product, and the crosslinking agent, which is 100% of the total mass; for example: 0.1 wt%, 0.5 wt%, 1 wt%, 2.5 wt%, 3.5 wt%, 4 wt%, 4.5 wt%, 7 wt%, 9 wt%, etc. When the initiator content is 0.05-10 wt%, the desired functional copolymer can be obtained.

[0129] The present invention does not impose any particular limitation on the solvent, and it can be a solvent commonly used in the art. Specifically, the solvent is an organic solvent, and preferably, the organic solvent includes one or more of hydrocarbon solvents, ketone solvents, carboxylic acid ester solvents, and ether solvents.

[0130] The hydrocarbon solvent can be at least one selected from alkane solvents and aromatic solvents, preferably one or a combination of two or more selected from n-hexane, cyclohexane, benzene, toluene, and xylene.

[0131] Carboxylic acid ester solvents can have the structure shown in formula (I):

[0132] Formula (I)

[0133] In formula (I), R1 is a hydrogen atom, a C1-C6 alkyl or a C6-C10 aryl, and R2 is a C1-C8 alkyl or a C6-C10 aryl; specifically, the C6-C10 aryl can be phenyl, benzyl, phenethyl, etc.

[0134] Specific examples of carboxylic acid ester solvents can be ester solvents consisting of one or more combinations of ethyl formate, propyl formate, isobutyl formate, amyl formate, ethyl acetate, butyl acetate, isobutyl acetate, amyl acetate, isoamyl acetate, benzyl acetate, phenyl acetate, methyl propionate, ethyl propionate, propyl propionate, butyl propionate, methyl butyrate, ethyl butyrate, propyl butyrate, butyl butyrate, isobutyl butyrate, isoamyl butyrate, ethyl isobutyrate, ethyl isovalerate, isoamyl isovalerate, methyl benzoate, ethyl benzoate, propyl benzoate, butyl benzoate, isoamyl benzoate, methyl phenylacetate, ethyl phenylacetate, propyl phenylacetate, butyl phenylacetate, isoamyl phenylacetate, etc.

[0135] Ketone solvents can be selected from one or more of acetone, butanone, cyclohexanone, methyl isobutyl ketone, methyl isopropyl ketone, etc.

[0136] Ether solvents may be selected from one or more combinations of dimethyl ether, methyl ethyl ether, ethyl ether, ethyl propyl ether, dipropyl ether, dibutyl ether, methyl propyl ether, methyl butyl ether, methyl isobutyl ether, methyl tert-butyl ether, methyl isopentyl ether, methyl tert-amyl ether, methyl cyclopentyl ether, ethylene glycol dimethyl ether, ethylene glycol diethyl ether, tetrahydrofuran, tetrahydropyran, 1,4-dioxane, etc.

[0137] The present invention does not impose any particular limitation on the amount of solvent used, and it can be added as needed, as long as the electron-accepting monomer, Fischer-Tropsch synthesis product, crosslinking agent and initiator can be fully dissolved.

[0138] Preferably, the mass ratio of solvent to electron-accepting monomer is (1~15):1, more preferably (2~14):1, more preferably (3~13.5):1, and even more preferably (3.5~13):1, for example 4:1, 5:1, 6:1, 7:1, 8:1, 9:1, 10:1, 11:1, 12:1.

[0139] <Polymerization Process>

[0140] In this invention, there are no particular restrictions on the mixing order and method of the components in the reaction system; they can be mixed in any suitable manner and order.

[0141] In a specific implementation, the precipitation polymerization method of the present invention includes the following steps: mixing the electron-accepting monomer, the initiator, and the Fischer-Tropsch synthesis product, and then adding the crosslinking agent, so that the resulting reaction system undergoes precipitation polymerization.

[0142] In a specific implementation, the precipitation polymerization method of the present invention includes the following steps: mixing the electron-accepting monomer with the initiator, adding the Fischer-Tropsch synthesis product, and then adding the crosslinking agent, so that the resulting reaction system undergoes precipitation polymerization.

[0143] The solvent can be added to the reaction system at any suitable time. Preferably, the electron-accepting monomer and the initiator are added separately to the solvent and mixed.

[0144] The polymerization reaction is initiated by heating the reaction system to the polymerization temperature. The polymerization temperature can be 50–120 °C, preferably 60–110 °C, for example: 55 °C, 60 °C, 65 °C, 70 °C, 75 °C, 80 °C, 85 °C, 90 °C, 95 °C, 100 °C, 105 °C, 110 °C, 115 °C, etc. The polymerization time can be 1–24 hours, for example: 2 hours, 5 hours, 8 hours, 10 hours, 12 hours, 15 hours, 18 hours, 20 hours, 22 hours, etc. Furthermore, the polymerization reaction is carried out under the protection of an inert gas, specifically, nitrogen or argon.

[0145] In a more specific embodiment, the electron-accepting monomer and the initiator are respectively added to a solvent for mixing, the Fischer-Tropsch synthesis product and the crosslinking agent are added, an inert gas is then introduced into the reaction system, and the reaction system is heated to the polymerization reaction temperature for precipitation polymerization.

[0146] In a specific implementation, the precipitation polymerization method of the present invention further includes a post-treatment step of the reaction system after precipitation polymerization, wherein the post-treatment preferably includes one or more of solid-liquid separation, washing or drying.

[0147] Based on the precipitation polymerization method of the present invention, the reaction system obtained after polymerization is a dispersion system of copolymer microspheres. Therefore, no precipitant is needed, and the copolymer microspheres can be separated by solid-liquid separation alone.

[0148] More specifically, after the polymerization reaction, the reaction system is subjected to solid-liquid separation, and optionally the separated solid (polymer microspheres) is washed and / or dried.

[0149] Solid-liquid separation can be performed using known methods, such as filtration, centrifugation, and solvent evaporation.

[0150] Washing can be carried out by rinsing the separated solids with a washing solvent, dispersing the separated solids in a washing solvent, and then performing solid-liquid separation again. The washing solvent is preferably the solvent used in the reaction.

[0151] Drying can be carried out by methods known in the art, such as evaporating the residual solvent by heating. The drying temperature can be 40~150 °C, for example 40~100 °C, and the drying time can be 1~48 hours, for example 4~40 hours or 8~30 hours.

[0152] <Copolymer>

[0153] The present invention also relates accordingly to copolymers obtained by the method of the present invention. The copolymers of the present invention are copolymers of olefins, electron-accepting monomers, and crosslinking agents.

[0154] The copolymer of the present invention is a copolymer microsphere with a number-average particle size of 0.1~10 μm, preferably 0.2~8 μm, more preferably 0.3~6 μm, and even more preferably 0.4~5 μm; for example, 0.5 μm, 0.6 μm, 0.7 μm, 0.8 μm, 0.9 μm, 1.2 μm, 1.4 μm, 1.5 μm, 1.6 μm, 0.5 μm, 1.9 μm, 2.2 μm, 2.4 μm, 2.6 μm, 2.8 μm, 2.9 μm, 3.0 μm, 3.1 μm, 3.2 μm, 3.3 μm, 3.4 μm, 3.5 μm, 3.6 μm, 3.7 μm, 3.8 μm, 3.9 μm, 4.0 μm, 4.1 μm, 4.2 μm, 4.3 μm, 4.4 μm, 4.5 μm. μm, 4.6 μm, 4.7 μm, 4.8 μm, 4.9 μm, 5.0 μm, 5.1 μm, 5.2 μm, 5.3μm, 5.4 μm, 5.5μm, 5.6 μm, 5.7 μm, 5.8 μm, 5.09 μm, etc.

[0155] The particle size distribution coefficient is 1.005~1.500, preferably 1.010~1.450, more preferably 1.015~1.400, such as 1.030, 1.050, 1.070, 1.100, 1.200, 1.300, 1.350, etc.

[0156] The copolymer microspheres obtained by the method of the present invention have a residual solvent content of 5% by mass or less, preferably 3% by mass or less, more preferably 2% by mass or less, and even 1% by mass or less.

[0157] In one embodiment, the gel content of the copolymer can be 5% to 100%, preferably 6% to 98%, more preferably 8% to 97%, such as 15%, 28%, 34%, 38%, 42%, 67%, 79%, 84%, etc.

[0158] Example

[0159] The embodiments of the present invention will be described in detail below with reference to examples. However, those skilled in the art will understand that the following examples are for illustrative purposes only and should not be considered as limiting the scope of the invention. Unless otherwise specified in the examples, conventional conditions or conditions recommended by the manufacturer are followed. Reagents or instruments whose manufacturers are not specified are all commercially available conventional products.

[0160] The composition of the Fischer-Tropsch synthetic oil-washed naphtha (also referred to as "oil-washed naphtha") used in the following examples is shown in Table 1 below:

[0161] Table 1

[0162]

[0163] The composition of the Fischer-Tropsch stabilized heavy oil (also referred to as "stabilized heavy oil") used in the following examples is shown in Table 2 below:

[0164] Table 2

[0165]

[0166] The composition (average carbon number 22.13) of the Fischer-Tropsch synthetic waxes used in the following examples is shown in Table 3 below:

[0167] Table 3

[0168]

[0169] Example 1

[0170] 0.96 g of maleic anhydride and 0.103 g of benzoyl peroxide (BPO) were dissolved in 4.4 g of methyl tert-butyl ether solvent. The solution was sonicated until dissolved and mixed thoroughly to obtain a clear solution. Then, 1.28 g of Fischer-Tropsch synthetic oil was added to wash naphtha, followed by 0.40 g of diallyl maleate. The system was purged with nitrogen for 10 minutes and reacted at 80 °C for 8 hours to obtain a dispersion of maleic anhydride-α-olefin crosslinked copolymer microspheres. After centrifugation and vacuum drying at 80 °C for 24 hours, 1.76 g of maleic anhydride-α-olefin crosslinked copolymer microspheres were obtained as a white solid, with a yield of 83%.

[0171] Example 2

[0172] 9.9 g of maleic anhydride and 0.9 g of benzoyl peroxide were dissolved in 70 g of methyl tert-butyl ether solvent. The solution was sonicated until dissolved and mixed thoroughly to obtain a clear solution. Then, 5.7 g of Fischer-Tropsch synthetic oil was added to wash naphtha, followed by 4.7 g of dicyclopentadiene. The system was purged with nitrogen for 10 minutes and reacted at 80 °C for 24 hours to obtain a dispersion of maleic anhydride-α-olefin crosslinked copolymer microspheres. After centrifugation and vacuum drying at 80 °C for 24 hours, 12.7 g of maleic anhydride-α-olefin crosslinked copolymer microspheres were obtained as a white solid, with a yield of 70%.

[0173] Example 3

[0174] 0.59 g of maleic anhydride and 0.07 g of benzoyl peroxide were dissolved in 5 g of methyl tert-butyl ether solvent. The solution was sonicated until dissolved and mixed thoroughly to obtain a clear solution. Then, 1.01 g of Fischer-Tropsch synthetic oil was added to wash naphtha, followed by 0.31 g of divinylbenzene. The system was purged with nitrogen for 10 minutes and reacted at 80 °C for 1 hour to obtain a dispersion of maleic anhydride-α-olefin crosslinked copolymer microspheres. After centrifugation and vacuum drying at 80 °C for 24 hours, 0.77 g of maleic anhydride-α-olefin crosslinked copolymer microspheres were obtained as a white solid, with a yield of 56%.

[0175] Example 4

[0176] 1.0 g of maleic anhydride and 0.106 g of benzoyl peroxide were dissolved in 4.4 g of methyl tert-butyl ether solvent. The solution was sonicated until dissolved and mixed thoroughly to obtain a clear solution. Then, 1.37 g of Fischer-Tropsch synthetic oil was added to wash naphtha, followed by 0.26 g of diallyl phthalate. The system was purged with nitrogen for 10 minutes and reacted at 80 °C for 8 hours to obtain a dispersion of maleic anhydride-α-olefin crosslinked copolymer microspheres. After centrifugation and vacuum drying at 80 °C for 24 hours, 1.62 g of maleic anhydride-α-olefin crosslinked copolymer microspheres were obtained as a white solid, with a yield of 77%.

[0177] Example 5

[0178] 1.2 g of maleic anhydride and 0.105 g of benzoyl peroxide were dissolved in 4.4 g of methyl tert-butyl ether solvent. The solution was sonicated until dissolved and mixed thoroughly to obtain a clear solution. Then, 1.14 g of Fischer-Tropsch synthetic oil was added to wash naphtha, followed by 0.25 g of triallyl isocyanurate. The system was purged with nitrogen for 10 minutes and reacted at 80 °C for 8 hours to obtain a dispersion of maleic anhydride-α-olefin crosslinked copolymer microspheres. After centrifugation and vacuum drying at 80 °C for 24 hours, 1.66 g of maleic anhydride-α-olefin crosslinked copolymer microspheres were obtained as a white solid, with a yield of 79%.

[0179] Example 6

[0180] 0.96 g of maleic anhydride and 0.103 g of benzoyl peroxide were dissolved in 4.4 g of xylene solvent. The solution was sonicated until dissolved and mixed thoroughly to obtain a clear solution. Then, 1.28 g of Fischer-Tropsch synthetic oil was added to wash naphtha, followed by 0.4 g of diallyl maleate. The system was purged with nitrogen for 10 minutes and reacted at 80 °C for 8 hours to obtain a dispersion of maleic anhydride-α-olefin crosslinked copolymer microspheres. After centrifugation and vacuum drying at 80 °C for 24 hours, 1.83 g of maleic anhydride-α-olefin crosslinked copolymer microspheres were obtained as a white solid, with a yield of 86%.

[0181] Example 7

[0182] 0.95 g of maleic anhydride and 0.104 g of benzoyl peroxide were dissolved in a mixed solvent of 3.4 g of methyl tert-butyl ether and 0.8 g of acetone. The solution was sonicated until dissolved and mixed thoroughly to obtain a clear solution. Then, 1.64 g of Fischer-Tropsch synthetic oil was added to wash naphtha, followed by 0.26 g of divinylbenzene. The system was purged with nitrogen for 10 minutes and reacted at 80 °C for 6 hours to obtain a dispersion of maleic anhydride-α-olefin crosslinked copolymer microspheres. After centrifugation and vacuum drying at 80 °C for 24 hours, 0.80 g of maleic anhydride-α-olefin crosslinked copolymer microspheres were obtained as a white solid, with a yield of 38%.

[0183] Example 8

[0184] 0.96 g of maleic anhydride and 0.105 g of azobisisobutyronitrile (AIBN) were dissolved in 4.5 g of methyl tert-butyl ether solvent. The solution was sonicated until dissolved and mixed thoroughly to obtain a clear solution. Then, 0.99 g of Fischer-Tropsch synthetic oil was added to wash naphtha, followed by 0.54 g of dicyclopentadiene. The system was purged with nitrogen for 10 minutes and reacted at 70 °C for 8 hours to obtain a dispersion of maleic anhydride-α-olefin crosslinked copolymer microspheres. After centrifugation and vacuum drying at 80 °C for 24 hours, 1.03 g of white solid maleic anhydride-α-olefin crosslinked copolymer microspheres were obtained, with a yield of 49%.

[0185] Example 9

[0186] 0.66 g of maleic anhydride and 0.105 g of benzoyl peroxide were dissolved in 4.1 g of methyl tert-butyl ether solvent. The solution was sonicated until dissolved and mixed thoroughly to obtain a clear solution. Then, 1.93 g of Fischer-Tropsch stabilized heavy oil and 0.30 g of 1,4-butanediol diacrylate were added. The system was purged with nitrogen for 10 minutes and reacted at 80 °C for 8 hours to obtain a dispersion of maleic anhydride-α-olefin crosslinked copolymer microspheres. After centrifugation and vacuum drying at 80 °C for 24 hours, 0.76 g of maleic anhydride-α-olefin crosslinked copolymer microspheres as a white solid were obtained, with a yield of 36%.

[0187] Example 10

[0188] 0.16 g of maleic anhydride and 0.105 g of benzoyl peroxide were dissolved in 2.0 g of methyl tert-butyl ether solvent. The solution was sonicated until dissolved and mixed thoroughly to obtain a transparent solution. Then, 4.75 g of Fischer-Tropsch wax and 0.08 g of divinylbenzene were added. The system was purged with nitrogen for 10 minutes and reacted at 80 °C for 6 hours to obtain a dispersion of maleic anhydride-α-olefin crosslinked copolymer microspheres. After centrifugation and vacuum drying at 80 °C for 24 hours, 0.32 g of maleic anhydride-α-olefin crosslinked copolymer microspheres as a white solid were obtained, with a yield of 46%.

[0189] Example 11

[0190] 1.02 g itaconic anhydride and 0.105 g benzoyl peroxide were dissolved in 4.6 g methyl tert-butyl ether solvent. The solution was sonicated until dissolved and mixed thoroughly to obtain a clear solution. Then, 0.76 g of Fischer-Tropsch synthetic oil was added to wash naphtha, followed by 0.63 g diallyl maleate. The system was purged with nitrogen for 10 minutes and reacted at 80 °C for 8 hours to obtain a dispersion of itaconic anhydride-α-olefin crosslinked copolymer microspheres. After centrifugation and vacuum drying at 80 °C for 24 hours, 1.29 g of white solid itaconic anhydride-α-olefin crosslinked copolymer microspheres were obtained, with a yield of 61%.

[0191] Example 12

[0192] 1.02 g of maleimide and 0.105 g of benzoyl peroxide were dissolved in 4.3 g of methyl tert-butyl ether solvent. The solution was sonicated until dissolved and mixed thoroughly to obtain a clear solution. Then, 1.37 g of Fischer-Tropsch synthetic oil was added to wash naphtha, followed by 0.26 g of diallyl terephthalate. The system was purged with nitrogen for 10 minutes and reacted at 80 °C for 8 hours to obtain a dispersion of maleimide-α-olefin crosslinked copolymer microspheres. After centrifugation and vacuum drying at 80 °C for 24 hours, 1.63 g of maleimide-α-olefin crosslinked copolymer microspheres as a white solid were obtained, with a yield of 78%.

[0193] <Tests and Evaluations>

[0194] SEM analysis

[0195] Small amounts of the dried copolymer microspheres obtained in Examples 1, 3, and 5 were dispersed in appropriate amounts of the solvent used in the polymerization reaction. After being ultrasonically dispersed evenly, the dispersions were dropped onto coverslips and allowed to air dry. The morphology was observed using a field emission scanning electron microscope (JEOL, model: JSM7401). SEM images of the copolymer microspheres in Examples 1, 3, and 5 were obtained, as shown below. Figs. 1-3 As shown.

[0196] Particle size analysis

[0197] The particle size and distribution data of the copolymer microspheres obtained in Examples 1-12 were obtained by the following methods:

[0198] First, the particle size and particle size distribution of the microspheres in the scanning electron microscope image are measured using measurement and statistical software. The particle size and distribution of the measured microspheres can be obtained by formula (1)~(3).

[0199]

[0200] in

[0201]

[0202] Gel content determination

[0203] Weigh a certain mass of the copolymer, immerse the copolymer in tetrahydrofuran, and extract for more than 24 hours. Dry the insoluble matter and weigh it. The gel content of the copolymer can be calculated using formula (4).

[0204]

[0205] in

[0206]

[0207] The properties and evaluation results of the copolymer microspheres obtained in Examples 1-12 are shown in Table 4.

[0208] Table 4

[0209]

[0210] As shown in Table 4, by adding a crosslinking agent, different types of Fischer-Tropsch synthesis products can achieve precipitation polymerization in different solvents, obtaining microspheres with particle sizes ranging from 0.6 to 4.7 μm, a gel content of 10% to 96%, and high product yield. The method of this invention can achieve precipitation polymerization of Fischer-Tropsch synthetic oils or Fischer-Tropsch synthetic waxes.

[0211] Industrial availability

[0212] The precipitation polymerization method of the Fischer-Tropsch synthesis products of the present invention can be widely used in industry to prepare various functional copolymer microspheres using Fischer-Tropsch synthesis products.

Claims

1. A precipitation polymerization method, characterized in that, Includes the following steps: Precipitation polymerization is carried out on a reaction system containing Fischer-Tropsch synthesis products, electron-accepting monomers, crosslinking agents, initiators, and solvents; The crosslinking group of the crosslinking agent is a group having a carbon-carbon double bond; The Fischer-Tropsch synthesis product contains electron-donating monomers.

2. The precipitation polymerization method according to claim 1, characterized in that, The electron-accepting monomer is selected from one or more of maleic anhydride, maleimide, itaconic anhydride and their derivatives; The Fischer-Tropsch synthetic products are Fischer-Tropsch synthetic oils and / or Fischer-Tropsch synthetic waxes; The crosslinking agent has 2 to 6 crosslinking groups, each crosslinking group being independently selected from alkenyl, (meth)acryloyl, and maleimide groups; The initiator is one or more selected from azo compound initiators and peroxide initiators; The solvent is an organic solvent.

3. The precipitation polymerization method according to claim 2, characterized in that, The electron-accepting monomer is selected from one or more of maleic anhydride, itaconic anhydride, maleimide, N-phenylmaleimide, N-methylmaleimide, N-ethylmaleimide, and N-(1-naphthyl)maleimide; The Fischer-Tropsch synthetic oil is Fischer-Tropsch synthetic oil washed naphtha and / or Fischer-Tropsch synthetic stabilized heavy oil; the content of electron-donating monomers in the Fischer-Tropsch synthetic product is 1-70% by mass; the electron-donating monomers are preferably one or more combinations of olefins with 4-40 carbon atoms, preferably α-olefins; The crosslinking agent has 2 to 4 crosslinking groups; each crosslinking group is independently selected from vinyl, vinylidene (-CH=CH-), allyl, conjugated dienyl, (meth)acrylate, (meth)acrylamide, and maleimide groups; The solvent is selected from one or more of hydrocarbon solvents, ketone solvents, carboxylic acid ester solvents, and ether solvents; The azo compound initiator is azobisisobutyronitrile (AIBN) or azobisisoheptanenitrile (AIHH)nitrile. The peroxide initiator is benzoyl peroxide, dicumyl peroxide, ditert-butyl peroxide, dodecyl peroxide, tert-butyl peroxide, diisopropyl peroxide, or dicyclohexyl peroxide.

4. The precipitation polymerization method according to any one of claims 1 to 3, characterized in that, The crosslinking agent is selected from one or more of polyolefins, alkenyl ethers, polyfunctional (meth)acrylates, polyfunctional (meth)acrylamides, bismaleimide, (meth)acrylate alkenyl esters, and polyfunctional allyl esters.

5. The precipitation polymerization method according to any one of claims 1 to 3, characterized in that, In the reaction system, the total concentration of electron-donating and electron-accepting monomers is 5-75% by mass; Based on the total mass of electron-donating monomers, electron-accepting monomers and crosslinking agents as 100%, the mass fraction of the crosslinking agent is 0.1 to 45% by mass, preferably 0.5 to 42% by mass, and more preferably 1 to 38% by mass; The mass ratio of the electron-accepting monomer to the Fischer-Tropsch synthesis product is 1:30 to 5:

1. The amount of initiator is 0.05 to 10% by mass, based on the total mass of the electron-accepting monomer, electron-donating monomer, and crosslinking agent as 100%.

6. The precipitation polymerization method according to any one of claims 1 to 3, characterized in that, The electron-accepting monomer and the initiator are respectively added to the solvent and mixed. Then, the Fischer-Tropsch synthesis product and the crosslinking agent are added. Then, an inert gas is introduced into the system, and the reaction system is heated to the polymerization reaction temperature to carry out precipitation polymerization.

7. The precipitation polymerization method according to any one of claims 1 to 3, characterized in that, The precipitation polymerization is carried out in an inert gas at a polymerization temperature of 50-120 °C for 1-24 hours.

8. The precipitation polymerization method according to any one of claims 1 to 3, characterized in that, It also includes a post-treatment step for the reaction system after precipitation polymerization, wherein the post-treatment preferably includes one or more of solid-liquid separation, washing or drying.

9. A copolymer obtained by the precipitation polymerization method according to any one of claims 1 to 8.

10. The copolymer according to claim 9, characterized in that, The copolymer is a copolymer microsphere with a number-average particle size of 0.1~10 μm, a particle size distribution coefficient of 1.005~1.500, and a gel content of 5~100% by mass.

Images