Polymer microspheres, functional microspheres with isocyanate groups, and polymer-supported catalysts

Abstract

The present invention relates to a polymer microsphere, a functional microsphere with an isocyanate group, and a polymer-supported catalyst. The polymer microsphere of the present invention is obtained by polymerizing at least one monomer selected from the monomers represented by formula (1) and the monomers represented by formula (2) and an optional unsaturated dicarboxylic anhydride monomer by a self-stabilizing precipitation polymerization method. #imgabs0#In formula (1), R1 is a hydrogen atom or a methyl group, R2 and R3 each independently represent a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, or an aryl group having 6 to 12 carbon atoms, and at least one of R2 and R3 is a hydrogen atom. #imgabs1#In formula (2), R4 and R5 each independently represent a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, or an aryl group having 6 to 12 carbon atoms; with respect to the entire polymer microsphere, the ratio of the units based on at least one monomer selected from the monomers represented by formula (1) and the monomers represented by formula (2) is 20 mol% or more.

Description

Technical Field

[0001] The present invention relates to a polymer microsphere, a functional microsphere with isocyanate groups obtained from the polymer microsphere, and a polymer-supported catalyst. Background Art

[0002] With the development of science and industry, the problem of water pollution has become increasingly serious, which poses a great threat to human health and the ecosystem. The main sources of water pollution include industrial pollution sources, agricultural pollution sources, and domestic pollution sources, etc. Wastewater mainly contains inorganic substances (acids, alkalis, inorganic salts, etc.) and organic substances (dyes, pesticides, bacteria, viruses, etc.). Traditional wastewater treatment methods require complex equipment, take a long time, and consume a large amount of energy. Photocatalysis technology is a new type of wastewater treatment technology that does not produce secondary pollution and has a wide range of applications. It mainly uses semiconductor substances (such as C3N4, quantum dots, SnS2, TiO2, ZnO, SnO2, etc.) as catalysts. Under the irradiation of light sources such as ultraviolet light, the electrons of the catalyst are excited from the valence band (VB) to the conduction band (CB), thus forming electron-hole pairs. Among them, the valence band holes have strong oxidation ability, and the conduction band electrons have strong reduction ability. Most photocatalytic degradation utilizes the strong oxidation ability of the holes.

[0003] However, directly using semiconductor catalysts for wastewater treatment will cause problems such as difficult recovery and aggregation. Immobilizing the catalyst overcomes these deficiencies, not only maintaining the stability of the semiconductor catalyst but also improving the catalytic efficiency. The carriers for immobilizing the catalyst mainly include inorganic materials (such as silica, calcium silicate, etc.) and polymer organic materials (such as polyarylether nitrile, maleic anhydride copolymer, cellulose, etc.). The immobilization methods mainly include adsorption method, embedding method, crosslinking method, and covalent bonding method, etc. Among them, the covalent bonding method connects the catalyst to the surface of the carrier with reactive sites through covalent bonds. This covalent interaction is very strong and stable, and the inorganic semiconductor hardly falls off and has excellent environmental tolerance. However, some covalent connection operation processes are relatively complex, the crystal form of the semiconductor catalyst may be damaged, and there are limitations in the selection of the catalyst.

[0004] For carriers that can be used as supported catalysts, functional polymer microspheres have received extensive attention due to their advantages such as high specific surface area, monodispersity, and excellent mechanical properties. There are mainly two routes for the design of functional microspheres: one is to use functional monomers, and through the selection of appropriate polymerization methods, precisely design and synthesize functional polymers with a well-defined sequence structure, and effectively control the properties of the polymers; the other is to introduce functional groups into existing microspheres by physical or chemical means to improve their comprehensive performance. Mainly using polystyrene microspheres, poly(methyl methacrylate) microspheres, etc. as the matrix, groups such as hydroxyl, amino, carboxyl, mercapto, sulfonic acid groups, etc. are introduced onto the surface of the microspheres, thereby endowing the polymer microspheres with different functions.

[0005] However, traditionally, regardless of the preparation route, methods such as suspension polymerization, emulsion polymerization, and dispersion polymerization are usually adopted to prepare such polymer microspheres. However, it is very difficult to introduce a high density of functional groups onto the surface of the microspheres by such methods, and surfactants such as emulsifiers and dispersants will remain on the surface of the prepared polymer microspheres, and these surfactants are very difficult to be completely removed. This results in weak loading capacity of the prepared polymer microspheres when used as supported catalysts, and the catalytic effect of the prepared supported catalysts is limited. Moreover, the tunability of the composition of the polymer carriers prepared by the above methods is also limited, resulting in poor environmental adaptability of the obtained supported catalysts.

[0006] In addition, traditionally, the functional polymer microspheres obtained as above usually physically adsorb semiconductor catalysts by functional groups. This results in poor performance stability of the prepared supported catalysts.

[0007] Self-stabilized precipitation polymerization, as a heterogeneous polymerization method that can prepare monodisperse polymer microspheres without adding any stabilizers or dispersants, has received attention. However, due to its own polymerization mechanism, self-stabilized precipitation polymerization is very picky about the applicable comonomers and the ratio of comonomers. In addition, there are also differences in the stacking mode of polymer molecular chains between the polymer microspheres obtained by self-stabilized precipitation polymerization and those obtained by other traditional methods. However, there is no research in the prior art on whether the polymer microspheres obtained by self-stabilized precipitation polymerization can be used to prepare polymer carriers that can make up for the above defects.

[0008] Therefore, in the field of photocatalysis technology, there is a need for polymer microspheres prepared by self-stabilized precipitation polymerization that are suitable for forming catalyst carriers, and supported catalysts based on such polymer microspheres, which have high catalytic efficiency, high performance stability, and strong environmental adaptability. Summary of the Invention

[0009] Problems to be Solved by the Invention

[0010] Aiming at the above-mentioned defects in the art, the technical problem to be solved by the present invention is to provide a polymer microsphere, which is obtained by self-stabilized precipitation polymerization, is suitable for forming a polymer carrier for supporting a semiconductor catalyst, and the prepared supported catalyst has high catalytic efficiency, high performance stability, and strong environmental adaptability.

[0011] The technical problem to be solved by the present invention is also to provide a functional microsphere with isocyanate groups, which is suitable as a polymer carrier for a semiconductor catalyst, and the prepared supported catalyst has high catalytic efficiency, high performance stability, and strong environmental adaptability.

[0012] The technical problem to be solved by the present invention also lies in a novel supported catalyst, which has excellent catalytic effect, high performance stability and strong environmental adaptability.

[0013] Solutions for Solving the Problems

[0014] According to the intensive research of the inventors of the present invention, it is found that by implementing the following technical solutions, the above technical problems can be solved:

[0015] [1]. A polymer microsphere, wherein the polymer microsphere is obtained by polymerizing at least one monomer selected from the monomers represented by formula (1) and the monomers represented by formula (2) and an optional unsaturated dicarboxylic anhydride monomer by self-stabilizing precipitation polymerization,

[0016]

[0017] In formula (1), R1 is a hydrogen atom or a methyl group, R2 and R3 each independently represent a hydrogen atom, an alkyl group having 1 to 6 carbon atoms or an aryl group having 6 to 12 carbon atoms, and at least one of R2 and R3 is a hydrogen atom,

[0018]

[0019] In formula (2), R4 and R5 each independently represent a hydrogen atom, an alkyl group having 1 to 6 carbon atoms or an aryl group having 6 to 12 carbon atoms;

[0020] Relative to the entire polymer microsphere, the ratio of the units based on at least one monomer selected from the monomers represented by formula (1) and the monomers represented by formula (2) is 20 mol% or more.

[0021] [2]. The polymer microsphere according to [1], wherein the polymer microsphere is obtained by copolymerizing at least one monomer selected from the monomers represented by formula (1) and the monomers represented by formula (2) without using an unsaturated dicarboxylic anhydride monomer,

[0022] Relative to the entire polymer microsphere, the ratio of the units based on at least one monomer selected from the monomers represented by formula (1) and the monomers represented by formula (2) is 45 mol% or more.

[0023] [3]. The polymer microsphere according to [2], wherein the polymer microsphere is obtained only by polymerizing at least one monomer selected from the monomers represented by formula (1) and the monomers represented by formula (2), or

[0024] the polymer microsphere is obtained only by polymerizing at least one monomer selected from the monomers represented by formula (1) and the monomers represented by formula (2) and a monomer having two or more carbon-carbon double bonds.

[0025] [4]. The polymer microspheres according to [1], wherein the polymer microspheres are obtained by polymerizing at least one monomer selected from the monomers represented by formula (1) and the monomers represented by formula (2) and an unsaturated dicarboxylic anhydride monomer,

[0026] With respect to the entire polymer microspheres, the ratio of the units based on at least one monomer selected from the monomers represented by formula (1) and the monomers represented by formula (2) is 20 mol% or more and 90 mol% or less.

[0027] [5]. The polymer microspheres according to [4], wherein in the polymer microspheres, the molar ratio of the units based on at least one monomer selected from the monomers represented by formula (1) and the monomers represented by formula (2) to the units based on the unsaturated dicarboxylic anhydride monomer is 1 / 5 to 5 / 1.

[0028] [6]. The polymer microspheres according to [4], wherein the polymer microspheres are obtained by polymerizing only at least one monomer selected from the monomers represented by formula (1) and the monomers represented by formula (2) and an unsaturated dicarboxylic anhydride monomer, or

[0029] The polymer microspheres are obtained by polymerizing only at least one monomer selected from the monomers represented by formula (1) and the monomers represented by formula (2), an unsaturated dicarboxylic anhydride monomer and a monomer having two or more carbon-carbon double bonds.

[0030] [7]. The polymer microspheres according to any one of [1] to [6], wherein the average particle diameter of the polymer microspheres is 0.1 μm to 2 μm.

[0031] [8]. A functional microsphere with an isocyanate group, wherein the functional microsphere is obtained by reacting the active hydrogen atoms on the surface of the polymer microspheres according to any one of [1] to [7] with a diisocyanate compound.

[0032] [9]. The functional microsphere with an isocyanate group according to [8], wherein the active hydrogen atoms are derived from the units based on at least one monomer selected from the monomers represented by formula (1) and the monomers represented by formula (2) on the surface of the polymer microspheres; 20 mol% or more of all of the units based on at least one monomer selected from the monomers represented by formula (1) and the monomers represented by formula (2) on the surface of the polymer microspheres react with the diisocyanate compound.

[0033]

[10] . A polymer-supported catalyst, wherein the polymer-supported catalyst is obtained by reacting the isocyanate group on the surface of the functional microsphere with an isocyanate group according to [8] or [9] with a semiconductor catalyst.

[0034]

[11] . The polymer-supported catalyst according to

[10] , wherein the semiconductor catalyst is at least one selected from single-metal semiconductor catalysts and composite semiconductor catalysts containing two or more metals.

[0035] The single-metal semiconductor catalyst is at least one selected from ZnO, NiO, Cr2O3, MnO2, MoO3, V2O5, Fe3O4, TiO2, C3N4, BiOBr, CdS, ZnS, and the composite semiconductor catalyst is at least one selected from copper-based semiconductor catalysts, silver-based semiconductor catalysts, tungsten-based semiconductor catalysts, bismuth-based semiconductor catalysts, tin-based semiconductor catalysts, and indium-based semiconductor catalysts.

[0036]

[12] . The polymer-supported catalyst according to

[10] or

[11] , wherein the surface of the polymer-supported catalyst further has carboxylic acid groups and / or carboxylate groups.

[0037] Effects of the Invention

[0038] By implementing the above technical solutions, the present invention can achieve the following technical effects:

[0039] (1) The polymer microspheres with a specific composition obtained by the self-stabilizing precipitation polymerization method of the present invention itself have a microsphere structure suitable for forming a polymer carrier. Moreover, not only does it have a suitable catalyst loading capacity, but its molecular structure (including: the proportion of active hydrogen on the surface, whether it has units based on unsaturated dicarboxylic acid monomers, etc.) can also be adjusted within a wide range. Therefore, the supported catalyst based on the polymer microspheres has strong environmental adaptability. In addition, there is no surfactant residue on the surface of the polymer microspheres of the present invention, and there is a sufficient amount of active hydrogen (for example, N-H groups). Therefore, the supported catalyst prepared based on the polymer microspheres has high catalytic efficiency and high performance stability.

[0040] (2) The functional microspheres with isocyanate groups of the present invention are obtained based on the above polymer microspheres of the present invention. Therefore, the functional microspheres can be connected to the semiconductor catalyst through covalent bonds and are suitable as polymer carriers for semiconductor catalysts. Therefore, the prepared supported catalyst has high catalytic efficiency, high performance stability, and strong environmental adaptability.

[0041] (3) The supported catalyst of the present invention is obtained based on the above polymer microspheres of the present invention. Therefore, it has excellent catalytic effects, high performance stability, and strong environmental adaptability, and provides a new technical path in the field of supported catalysts. Further, the supported catalyst of the present invention can also have better water dispersibility and higher adsorption performance.

[0042] In addition, the supported catalyst of the present invention can be widely applied to the catalytic treatment of water-based pollutants (sewage) or oil-based pollutants, and is particularly suitable for the catalytic treatment of sewage. Description of the Drawings

[0043] Figure 1 It is a scanning electron microscope photograph of the polymer microspheres obtained in Example 1.

[0044] Figure 2 It is a scanning electron microscope photograph of the supported catalyst loaded with TiO2 obtained in Example 1.

[0045] Figure 3 It is the infrared spectra of the polymer microspheres, functional microspheres and supported catalyst loaded with TiO2 obtained in Example 1, respectively.

[0046] Figure 4 It is the ultraviolet spectrum of the supported catalyst loaded with TiO2 obtained in Example 1 for degrading methylene blue solution at different times. Detailed Description of the Invention

[0047] Various exemplary embodiments, features and aspects of the present invention will be described in detail below. The special term "exemplary" used here means "serving as an example, embodiment or illustration". Any embodiment described as "exemplary" here does not have to be construed as superior to or better than other embodiments.

[0048] In addition, in order to better illustrate the present invention, numerous specific details are given in the following detailed description. Those skilled in the art should understand that the present invention can also be implemented without some specific details. In other instances, methods, means, equipment and steps well-known to those skilled in the art are not described in detail in order to highlight the gist of the present invention.

[0049] Unless otherwise stated, the units used in this specification are all international standard units, and the numerical values and numerical ranges appearing in the present invention should be understood to include the systematic errors inevitable in industrial production.

[0050] In this specification, the numerical range expressed by "numerical value A to numerical value B" means a range including the end point numerical values A and B.

[0051] In this specification, the numerical ranges expressed by "above" and "below" mean ranges including the end point numerical values.

[0052] In this specification, the numerical ranges expressed by "greater than" and "less than" mean ranges not including the end point numerical values.

[0053] In this specification, if not otherwise specified, "%" all represents weight percentage.

[0054] In this specification, the meaning expressed by "may" includes both the meaning of performing a certain treatment and not performing a certain treatment, or includes both the meaning of having a certain component and not having a certain component.

[0055] In this specification, "optional" or "optionally" means that the events or circumstances described next may or may not occur, and this description includes the case where the event occurs and the case where the event does not occur.

[0056] In this specification, "(meth)acrylate" covers both "methacrylate" and "acrylate", and "(meth)acrylamide" covers both "methacrylamide" and "acrylamide".

[0057] In this specification, "alkyl" or "alkylene" means a straight-chain, branched-chain or cyclic unsubstituted "alkyl" or "alkylene", and "aryl" or "arylene" means a group having an aromatic group and no non-hydrocarbon substituents.

[0058] In this specification, the repeating units directly formed by monomer polymerization, and the units formed by chemically converting part or all of the substituents of the repeating units formed by monomer polymerization into other substituents are collectively referred to as "units based on...".

[0059] In this specification, unless otherwise specified, the "particle size" refers to the "average particle size", which can be measured by a commercial particle size analyzer or an electron scanning microscope.

[0060] In this specification, when "normal temperature" or "room temperature" is used, the temperature can be 10 - 40 °C.

[0061] In this specification, the "some specific / preferred embodiments", "other specific / preferred embodiments", "embodiments", etc. mentioned refer to the specific elements (e.g., features, structures, properties and / or characteristics) related to the embodiment, which are included in at least one of the embodiments described herein, and may or may not exist in other embodiments. Additionally, it should be understood that the elements can be combined in various embodiments in any suitable manner.

[0062] <<Polymer microspheres>>

[0063] The polymer microspheres of the present invention are obtained by polymerizing at least one monomer selected from the monomers represented by formula (1) and the monomers represented by formula (2) and an optional unsaturated dicarboxylic anhydride monomer using a self-stabilizing precipitation polymerization method.

[0064]

[0065] In formula (1), R1 is a hydrogen atom or a methyl group; R2 and R3 each independently represent a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, or an aryl group having 6 to 12 carbon atoms, and at least one of R2 and R3 is a hydrogen atom.

[0066]

[0067] In formula (2), R4 and R5 each independently represent a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, or an aryl group having 6 to 12 carbon atoms.

[0068] The ratio of the unit based on at least one monomer selected from the monomer represented by formula (1) and the monomer represented by formula (2) is 20 mol% or more relative to the entire polymer microspheres.

[0069] Through intensive research by the inventors, it has been found that the polymer microspheres obtained by polymerizing at least one monomer selected from the monomer represented by formula (1) and the monomer represented by formula (2) and an optional unsaturated dicarboxylic anhydride monomer by self-stabilizing precipitation polymerization have a molecular chain-packed microsphere structure suitable for a semiconductor catalyst carrier, not only retain a suitable catalyst loading capacity, but also the molecular structure can be adjusted within a wide range. In addition, no surfactant remains on its surface and it has an appropriate amount of active hydrogen (for example, N-H groups). Therefore, the polymer microspheres of the present invention are suitable for forming a polymer carrier loaded with a semiconductor catalyst, and the prepared supported catalyst has high catalytic efficiency, high performance stability, and strong environmental adaptability.

[0070] In some preferred embodiments, from the viewpoint of suppressing sedimentation or floating when the obtained polymer-supported catalyst catalyzes in a liquid system (especially a water-based system), the average particle diameter of the polymer microspheres is preferably 0.1 μm to 2 μm, more preferably 0.5 μm to 1.5 μm, and further preferably 0.8 μm to 1.2 μm.

[0071] Details of various monomers used to form the polymer microspheres are described in detail below.

[0072] <At least one monomer selected from the monomer represented by formula (1) and the monomer represented by formula (2)>

[0073] The monomer represented by formula (1) that can be used to form the polymer microspheres of the present invention is as described below.

[0074]

[0075] In formula (1), R1 is a hydrogen atom or a methyl group; R2 and R3 each independently represent a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, or an aryl group having 6 to 12 carbon atoms, and at least one of R2 and R3 is a hydrogen atom.

[0076] In some preferred embodiments, from the perspective of more easily achieving the technical effects of the present invention, R2 and R3 each independently preferably represent a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or an aryl group having 6 to 10 carbon atoms, and more preferably represent a hydrogen atom or an alkyl group having 1 to 4 carbon atoms.

[0077] For example, examples of the monomer represented by formula (1) include, but are not limited to, (meth)acrylamide, N-methyl(meth)acrylamide, N-ethyl(meth)acrylamide, N-isopropyl(meth)acrylamide, and the like.

[0078] The monomer represented by formula (2) that can be used to form the polymer microspheres of the present invention is as described below.

[0079]

[0080] In formula (2), R4 and R5 each independently represent a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, or an aryl group having 6 to 12 carbon atoms.

[0081] In some preferred embodiments, from the perspective of more easily achieving the technical effects of the present invention, R4 and R5 each independently preferably represent a hydrogen atom, an alkyl group having 1 to 3 carbon atoms, or an aryl group having 6 to 10 carbon atoms, and more preferably represent a hydrogen atom or an alkyl group having 1 to 2 carbon atoms.

[0082] For example, examples of the monomer represented by formula (2) include, but are not limited to, maleimide.

[0083] In some more preferred embodiments, at least one monomer selected from the monomer represented by formula (1) and the monomer represented by formula (2) is more preferably the monomer represented by formula (2).

[0084] To ensure the achievement of the technical effects of the present invention, the ratio of the unit based on at least one monomer selected from the monomer represented by formula (1) and the monomer represented by formula (2) is 20 mol% or more, for example, 25 mol% or more, 30 mol% or more, 50 mol% or more, 80 mol% or more, 90 mol% or more, etc., and can be adjusted according to different technical solutions.

[0085] <Unsaturated dicarboxylic anhydride monomer>

[0086] There is no particular limitation on the unsaturated dicarboxylic anhydride monomer that can be used to form the polymer microspheres of the present invention, and it can be appropriately selected according to actual needs.

[0087] In some preferred embodiments, from the perspective of being more easily involved in polymerization and thus more easily adjusting the surface properties of the polymer microspheres, the unsaturated dicarboxylic anhydride monomer is preferably at least one monomer selected from maleic anhydride, citraconic anhydride, and itaconic anhydride.

[0088] In some specific embodiments, with respect to the entire polymer microspheres, the ratio of the unit based on the unsaturated dicarboxylic anhydride monomer is preferably 80 mol% or less, for example, 60 mol% or less, 50 mol% or less, 20 mol% or less, 10 mol% or less, etc., and can be adjusted according to different technical solutions.

[0089] In some preferred embodiments, when using the unsaturated dicarboxylic anhydride monomer, in order to further improve the morphology of the polymer microspheres and improve the size uniformity of the polymer microspheres, the molar ratio of the unit based on at least one monomer selected from the monomer represented by formula (1) and the monomer represented by formula (2) to the unit based on the unsaturated dicarboxylic anhydride monomer (unit based on at least one monomer selected from the monomer represented by formula (1) and the monomer represented by formula (2) / unit based on the unsaturated dicarboxylic anhydride monomer) is preferably 1 / 5 to 5 / 1, more preferably 1 / 3 to 3 / 1, and further preferably 1 / 2 to 2 / 1.

[0090] In addition, in some preferred embodiments, when using the unsaturated dicarboxylic anhydride monomer, in order to balance the adsorption performance and catalytic performance of the supported catalyst, the molar ratio of the active hydrogen groups (H connected to N) on the surface of the polymer microspheres to the anhydride groups is preferably 5 / 1 to 1 / 3, more preferably 3 / 1 to 1 / 1, and further preferably 2 / 1 to 1 / 1.

[0091] <Monomer having two or more carbon-carbon double bonds>

[0092] In addition to at least one monomer selected from the monomer represented by formula (1) and the monomer represented by formula (2), and the unsaturated dicarboxylic anhydride monomer, the monomer that can be used to form the polymer microspheres of the present invention may optionally include a monomer having two or more carbon-carbon double bonds (hereinafter sometimes simply referred to as a crosslinking agent).

[0093] There is no particular limitation on the type of the crosslinking agent, and it can be appropriately selected as needed.

[0094] Examples of crosslinking agents include, but are not limited to: benzene-based monomers such as divinylbenzene; diene-based monomers such as butadiene, pentadiene, hexadiene, 1,9-decadiene, dicyclopentadiene; bismaleimide-based monomers such as 4,4'-bismaleimidodiphenylmethane; phthalate-based monomers such as diallyl phthalate; poly(meth)acrylate-based monomers such as ethylene glycol di(meth)acrylate, propylene glycol di(meth)acrylate, glycerol tri(meth)acrylate, pentaerythritol tetra(meth)acrylate, etc. These crosslinking agents can be used alone or in combination of two or more.

[0095] In some specific embodiments, the ratio of the unit based on the crosslinking agent is preferably 50 mol% or less, more preferably 30 mol% or less, relative to the entire polymer microspheres.

[0096] <Electron-rich monomer having one carbon-carbon double bond>

[0097] In addition to at least one monomer selected from the monomers represented by formula (1) and the monomers represented by formula (2), and unsaturated dicarboxylic anhydride monomers, the monomers that can be used to form the polymer microspheres of the present invention may optionally include electron-rich monomers having one carbon-carbon double bond (hereinafter sometimes simply referred to as electron-rich monomers).

[0098] Examples of electron-rich monomers include, but are not limited to: styrene-based monomers such as styrene, α-methylstyrene, p-methylstyrene, p-methoxystyrene, ethylstyrene, 3,4-dimethylstyrene, tert-butylstyrene; indene-based monomers such as indene, coumarone; vinyl carboxylates such as vinyl acetate, vinyl propionate, vinyl butyrate; α-olefins such as propylene, 1-butene, 1-pentene, 1-hexene, 1-heptene; allyl ether-based monomers such as methyl allyl ether, ethyl allyl ether, phenyl allyl ether, butyl allyl ether; vinyl ether monomers such as methyl vinyl ether, ethyl vinyl ether, phenyl vinyl ether, butyl vinyl ether. These electron-rich monomers can be used alone or in combination of two or more.

[0099] In some specific embodiments, the ratio of the unit based on the electron-rich monomer is preferably 80 mol% or less, more preferably 60 mol% or less, relative to the entire polymer microspheres.

[0100] <Other monomers>

[0101] Within the scope not impairing the technical effects of the present invention, in addition to the above four monomers, the monomers that can be used to form the polymer microspheres of the present invention may optionally include other monomers. Here, the other monomers can be various monomers known in the art that can participate in free radical polymerization, such as other electron-deficient monomers except at least one monomer selected from the monomers represented by formula (1) and the monomers represented by formula (2).

[0102] <Scheme 1 without unsaturated dicarboxylic anhydride monomer>

[0103] In the present invention, as described above, the monomers used to form the polymer microspheres of the present invention may not contain unsaturated dicarboxylic anhydride monomers (Scheme 1).

[0104] In some preferred embodiments, the polymer microspheres of the present invention are obtained by polymerizing at least one monomer selected from the monomers represented by formula (1) and the monomers represented by formula (2) without using unsaturated dicarboxylic anhydride monomers, and the ratio of the units based on at least one monomer selected from the monomers represented by formula (1) and the monomers represented by formula (2) is 45 mol% or more with respect to the entire polymer microspheres.

[0105] In this case, the catalyst loading amount of the polymer support formed from the polymer microspheres can be adjusted within a wide range, and the heat resistance of the polymer microspheres is further improved, and further the heat resistance of the supported catalyst is improved.

[0106] In some more preferred embodiments, with respect to the entire polymer microspheres, the ratio of the units based on at least one monomer selected from the monomers represented by formula (1) and the monomers represented by formula (2) is more preferably 48 mol% or more, 50 mol% or more, or 85 mol% or more, 90 mol% or more, 100 mol%.

[0107] In this Scheme 1, in addition to at least one monomer selected from the monomers represented by formula (1) and the monomers represented by formula (2), the monomers used to form the polymer microspheres of the present invention may optionally contain the above crosslinking agent, may optionally contain the above electron-rich monomer, and may optionally contain the above other monomers. Here, the details of the types and amounts of the various monomers are as described above.

[0108] In some more preferred embodiments, from the viewpoint of stably obtaining polymer microspheres, the polymer microspheres are obtained by polymerizing at least one monomer selected from the monomers represented by formula (1) and the monomers represented by formula (2), an optional monomer having two or more carbon-carbon double bonds, and an optional electron-rich monomer having one carbon-carbon double bond.

[0109] In some particularly preferred embodiments, from the viewpoint of being more suitable for the preparation of polymer-supported catalysts, the polymer microspheres are obtained by polymerizing at least one monomer selected from the monomers represented by formula (1) and the monomers represented by formula (2).

[0110] In still other particularly preferred embodiments, from the viewpoint of being more suitable for the preparation of polymer-supported catalysts, the polymer microspheres are obtained by polymerizing at least one monomer selected from the monomers represented by formula (1) and the monomers represented by formula (2) and a monomer having two or more carbon-carbon double bonds. In this case, relative to the entire polymer microspheres, the ratio of the units based on at least one monomer selected from the monomers represented by formula (1) and the monomers represented by formula (2) is more preferably 45 mol% or more and less than 100 mol%.

[0111] This is because, when studying the polymer-supported catalysts, even though the mechanism is not yet clear, the inventors have unexpectedly found that the polymer-supported catalysts prepared from polymer microspheres obtained using electron-rich monomers having one carbon-carbon double bond, although effective, are not as effective as the above-mentioned particularly preferred embodiments (the same is true for the following Scheme 2 except for this scheme).

[0112] In addition, it is generally considered that electron-rich monomers having one carbon-carbon double bond, such as styrene, vinyl acetate, various olefins, etc., are monomers that must be used for the successful implementation of the self-stabilizing polymerization method.

[0113] <Scheme 2 including unsaturated dicarboxylic anhydride monomers>

[0114] In the present invention, as described above, the monomers used to form the polymer microspheres of the present invention may include unsaturated dicarboxylic anhydride monomers (Scheme 2).

[0115] In some preferred embodiments, the polymer microspheres of the present invention are obtained by polymerizing at least one monomer selected from the monomers represented by formula (1) and the monomers represented by formula (2) and an unsaturated dicarboxylic anhydride monomer, and relative to the entire polymer microspheres, the ratio of the units based on at least one monomer selected from the monomers represented by formula (1) and the monomers represented by formula (2) is 20 mol% or more and 90 mol% or less.

[0116] In this case, while ensuring the catalyst loading amount of the polymer support formed from the polymer microspheres and ensuring the heat resistance of the polymer microspheres, the hydrophilicity of the polymer microspheres is also improved, and the polymer microspheres are also given potential functionalizability (the resulting supported catalyst can also be further functionalized. For example, by hydrolysis or ammonolysis, the anhydride groups on the surface of the supported catalyst can be converted into hydrophilic carboxylic acid or carboxylate groups, giving it excellent water dispersibility and adsorption).

[0117] In the second embodiment, in addition to at least one monomer selected from the monomers represented by the formula (1) and the monomers represented by the formula (2) and the unsaturated dicarboxylic anhydride monomer, the monomers used to form the polymer microspheres of the present invention may optionally contain the above crosslinking agent, may optionally contain the above electron-rich monomer, and may optionally contain the above other monomers. Here, the details of the types and amounts of the various monomers are as described above.

[0118] In some more preferred embodiments, from the viewpoint of stably obtaining polymer microspheres, the polymer microspheres are obtained by polymerizing at least one monomer selected from the monomers represented by the formula (1) and the monomers represented by the formula (2), an unsaturated dicarboxylic anhydride monomer, an optional monomer having two or more carbon-carbon double bonds, and an optional electron-rich monomer having one carbon-carbon double bond.

[0119] In some particularly preferred embodiments, the polymer microspheres are obtained by polymerizing at least one monomer selected from the monomers represented by the formula (1) and the monomers represented by the formula (2) and an unsaturated dicarboxylic anhydride monomer. In this case, with respect to the entire polymer microspheres, the ratio of the units based on at least one monomer selected from the monomers represented by the formula (1) and the monomers represented by the formula (2) is more preferably 20 mol% or more and 90 mol% or less, and further preferably 30 mol% or more and 60 mol% or less.

[0120] In some other particularly preferred embodiments, the polymer microspheres are obtained by polymerizing at least one monomer selected from the monomers represented by the formula (1) and the monomers represented by the formula (2), an unsaturated dicarboxylic anhydride monomer, and a crosslinking agent. In this case, with respect to the entire polymer microspheres, the ratio of the units based on at least one monomer selected from the monomers represented by the formula (1) and the monomers represented by the formula (2) is more preferably 20 mol% or more and 60 mol% or less, the ratio of the units based on the unsaturated dicarboxylic anhydride monomer is more preferably 50 mol% or less, and the ratio of the units based on the crosslinking agent is more preferably 40 mol% or less.

[0121] <Method for manufacturing polymer microspheres>

[0122] As described above, the polymer microspheres of the present invention are prepared by self-stabilized precipitation polymerization.

[0123] As a non-limiting example, a specific manufacturing method may be as follows: Dissolve various monomers (at least one monomer selected from the monomers represented by formula (1) and the monomers represented by formula (2), an optional unsaturated dicarboxylic anhydride monomer, an optional crosslinking agent, and an optional electron-rich monomer), a radical initiator in a solvent so that the mass percentage concentration of all monomers is set to 2-40%, and from the viewpoint of improving the size, particle size distribution, and morphology of the polymer microspheres, more preferably 5-40%, and further preferably 10-30% (when there is a crosslinking agent, the crosslinking agent concentration is set to 2.5%-40%); the initiator concentration is set to 0.05%-5%, and from the viewpoint of improving the size, particle size distribution, and morphology of the polymer microspheres, more preferably 0.5%-3%, and further preferably 1%-2.5%. Then, heat to carry out a polymerization reaction (since the half-lives of different types of initiators vary at different temperatures, the reaction temperature and time need to be specifically adjusted according to the selected initiator, and there is no particular limitation. For example, the reaction temperature is 50-120°C, and the reaction time is 1-10 hours). After the polymerization is completed, the obtained polymer microspheres are separated by centrifugation and / or filtration, washed (for example, the washing solvent can be petroleum ether; non-polar alkane solvents, such as n-pentane, n-hexane, cyclohexane, n-heptane, n-octane, isooctane, n-nonane, n-decane, undecane, dodecane; methyl tert-butyl ether; alcohol solvents, such as methanol, ethanol, isopropanol. The number of washing times is not limited), and dried (using various drying methods known in the art) to obtain the polymer microspheres of the present invention.

[0124] During the polymerization reaction, the polymer that cannot be dissolved in the solvent forms polymer microspheres. Therefore, as the reaction proceeds, the polymer precipitates from the solvent. In addition, no surfactant is added during the polymerization reaction.

[0125] The radical initiator is a conventional radical initiator, which can be an azo initiator or a peroxide radical initiator. Azo initiators include: azobisisobutyronitrile, azobisisoheptonitrile, azobisisobutylamidine hydrochloride, azobisisobutimidazoline hydrochloride, azodicyanovaleric acid, azodiisopropylimidazoline, etc.; peroxide initiators include: benzoyl peroxide, bis(2,4-dichlorobenzoyl) peroxide, di-tert-butyl peroxide, lauroyl peroxide, tert-butyl peroxyneodecanoate, tert-butyl peroxypivalate, tert-butyl peroxyneodecanoate, tert-amyl peroxyneodecanoate, tert-butyl peroxybenzoate, di-sec-butyl peroxydicarbonate, bis(hexadecyl) peroxydicarbonate, diisopropyl peroxydicarbonate, dicyclohexyl peroxydicarbonate, cumene peroxide, di-tert-butyl peroxide, and di-tert-amyl peroxide, etc. These initiators can be used alone or in combination of two or more. The initiator is preferably azobisisoheptonitrile, azobisisobutyronitrile, and benzoyl peroxide, and further preferably azobisisobutyronitrile.

[0126] The solvent used in the self-stabilizing precipitation polymerization can be a single solvent or a mixed solvent.

[0127] In some preferred embodiments, the single solvent is preferably an organic acid ester solvent.

[0128] In some other preferred embodiments, the mixed solvent is preferably a combination of at least one selected from organic acid ester solvents, aromatic hydrocarbon solvents, ketone solvents and an alkane solvent. In some preferred embodiments, in the mixed solvent, the volume ratio of the organic acid ester solvent, at least one selected from organic acid ester solvents, aromatic hydrocarbon solvents, ketone solvents to the alkane solvent is preferably 1:3 to 3:1, more preferably 1.5:1 to 1:1.5.

[0129] Examples of the organic acid ester solvents include but are not limited to: ethyl formate, amyl formate, ethyl acetate, butyl acetate, benzyl acetate, isoamyl acetate, phenyl acetate, methyl propionate, ethyl propionate, propyl propionate, butyl propionate, methyl butyrate, ethyl butyrate, propyl butyrate, butyl butyrate, ethyl benzoate, butyl benzoate, ethyl phenylacetate, butyl phenylacetate, etc.

[0130] Examples of the aromatic hydrocarbon solvents include but are not limited to: toluene, ethylbenzene, xylene, etc.

[0131] Examples of the ketone solvents include but are not limited to: acetone, butanone, methyl acetone, 2-pentanone, 3-pentanone, 3-methyl-2-butanone, 2-hexanone, 3-hexanone, 2-methyl-3-pentanone, 3,3-dimethyl-2-butanone, 4-methyl-2-pentanone, 2-heptanone, 3-heptanone, 4-heptanone, 2,4-dimethyl-3-pentanone, 2-octanone, 2,6-dimethyl-4-heptanone, cyclopentanone, cyclohexanone, cycloheptanone, etc.

[0132] The alkane solvent can be an alkane having 4 to 12 carbon atoms, including but not limited to: n-pentane, n-hexane, cyclohexane, n-heptane, n-octane, isooctane, n-nonane, n-decane, undecane, dodecane, etc.

[0133] In some more preferred embodiments, the mixed solvent is preferably isoamyl acetate and n-heptane, isoamyl acetate and n-hexane, butanone and n-heptane, butanone and n-hexane, ethyl acetate and n-heptane, ethyl benzoate and n-heptane.

[0134] <<Functional microspheres with isocyanate groups>>

[0135] The functional microspheres with isocyanate groups of the present invention are obtained by reacting the active hydrogen atoms on the surface of the above polymer microspheres of the present application with a diisocyanate compound.

[0136] In the present invention, there is no particular limitation on the source of the active hydrogen atoms on the surface of the polymer microspheres. In some preferred embodiments, the active hydrogen atoms are derived from units based on at least one monomer selected from the monomers represented by formula (1) and the monomers represented by formula (2) on the surface of the polymer microspheres, that is, the active hydrogen atoms are H connected to N (which can be represented as N-H).

[0137] In addition, in order to further improve the catalytic effect of the obtained supported catalyst, more than 20 mol%, more preferably more than 60 mol%, and still more preferably more than 80 mol% of all the units based on at least one monomer selected from the monomers represented by formula (1) and the monomers represented by formula (2) on the surface of the polymer microspheres react with the diisocyanate compounds.

[0138] In the present invention, there is no particular limitation on the specific type of the diisocyanate compounds. However, from the viewpoint of more easily loading the semiconductor catalyst, the diisocyanate compounds are preferably at least one selected from isophorone diisocyanate, hexamethylene diisocyanate, toluene diisocyanate, diphenylmethane diisocyanate, trimethylhexamethylene diisocyanate, dicyclohexylmethane diisocyanate or xylylene diisocyanate.

[0139] In the present invention, there is no particular limitation on the manufacturing method for reacting the active hydrogen atoms on the surface of the above polymer microspheres of the present invention with the diisocyanate compounds, and various methods known in the art can be adopted.

[0140] As a non-limiting example, the specific manufacturing method can be as follows, for example:

[0141] First, disperse the above polymer microspheres of the present invention in a suitable solvent, add the diisocyanate and a catalyst, and mix them evenly. Further, react the isocyanate groups with the active hydrogen on the surface of the polymer microspheres, and introduce the isocyanate groups onto the microsphere surface through urethane bonds to obtain functional microspheres with isocyanate groups. After the reaction is completed, separate, wash, and dry the reaction product.

[0142] As the feeding amount, in some specific embodiments, the molar ratio of the diisocyanate to the units based on at least one monomer selected from the monomers represented by formula (1) and the monomers represented by formula (2) on the surface of the polymer microspheres is preferably 0.2:1 to 1.2:1, more preferably 0.5:1 to 1.1:1. In some other specific embodiments, the feeding amount of the catalyst is 0.5% by mass to 5% by mass of the mass of the polymer microspheres.

[0143] Examples of the catalyst include, but are not limited to, dioctyltin diacetate, dibutyltin dilaurate, dimethyltin dilaurate, dioctyltin dilaurate, dibutyltin dioleate, dioctyltin dioleate, dimethyltin dioleate, dibutyltin bis(isooctyl thioglycolate), dimethyltin bis(isooctyl thioglycolate), dioctyltin bis(isooctyl thioglycolate), dibutyltin dioctyl dodecanoate, dimethyltin dioctyl dodecanoate, dioctyltin dioctyl dodecanoate, dibutyltin diacetate, dimethyltin diacetate, dioctyltin diacetate, dibutyltin bis(acetylacetonate), dibutyltin bis(dodecyl mercaptan), dimethyltin bis(dodecyl mercaptan), dioctyltin bis(dodecyl mercaptan), dimethyltin oxide, dioctyltin oxide, stannous octoate, dibutyltin maleate, dimethyltin maleate, dioctyltin maleate, monobutyltin oxide, stannous oxalate.

[0144] Examples of the solvent for dispersing the polymer microspheres include, but are not limited to: ketone solvents such as acetone, methyl ethyl ketone, methyl propyl ketone, 2-pentanone, 3-pentanone, 3-methyl-2-butanone, 2-hexanone, 3-hexanone, 2-methyl-3-pentanone, 3,3-dimethyl-2-butanone, 4-methyl-2-pentanone, 2-heptanone, 3-heptanone, 4-heptanone, 2,4-dimethyl-3-pentanone, 2-octanone, 2,6-dimethyl-4-heptanone, cyclopentanone, cyclohexanone, cycloheptanone, etc.; cyclic ether solvents such as tetrahydrofuran, dioxane, etc.; amide solvents such as N,N-dimethylformamide, N,N-dimethylacetamide; sulfoxide solvents such as dimethyl sulfoxide; pyrrolidone solvents such as N-methylpyrrolidone.

[0145] <<Polymer-supported catalyst>>

[0146] The polymer-supported catalyst of the present invention is obtained by reacting the isocyanate groups on the surface of the above-mentioned functional microspheres with isocyanate groups in the semiconductor catalyst of the present invention.

[0147] In this case, the supported catalyst of the present invention is covalently bonded to the above-mentioned polymer carrier of the present invention, and thus has excellent catalytic effects, high performance stability, and strong environmental adaptability. Further, it may also have better water dispersibility and higher adsorption performance.

[0148] In the present invention, there is no particular limitation on the specific type of the semiconductor catalyst. However, from the perspective of better achieving the technical effects of the present invention, the semiconductor catalyst is preferably at least one selected from single-metal semiconductor catalysts and composite semiconductor catalysts containing two or more metals.

[0149] Among them, the single-metal semiconductor catalyst is more preferably at least one selected from ZnO, NiO, Cr2O3, MnO2, MoO3, V2O5, Fe3O4, TiO2, C3N4, BiOBr, CdS, ZnS; the composite semiconductor catalyst is more preferably at least one selected from copper-based semiconductor catalysts, silver-based semiconductor catalysts, tungsten-based semiconductor catalysts, bismuth-based semiconductor catalysts, tin-based semiconductor catalysts, indium-based semiconductor catalysts.

[0150] In some preferred embodiments, more than 80 mol%, preferably more than 90 mol% of the isocyanate groups on the surface of the functional microspheres react with the semiconductor catalyst to be connected with the semiconductor catalyst.

[0151] In addition, in some specific embodiments, when using polymer microspheres containing unsaturated dicarboxylic anhydride monomers to obtain polymer-supported catalysts, from the perspective of obtaining better water dispersibility and higher adsorption performance, the surface of the polymer-supported catalysts also has carboxylic acid groups and / or carboxylate groups.

[0152] In the present invention, there is no particular limitation on the manufacturing method for reacting the isocyanate groups on the surface of the above-mentioned functional microspheres with isocyanate groups of the present invention with the semiconductor catalyst, and various methods known in the art can be used.

[0153] As a non-limiting example, the specific manufacturing method can be as follows:

[0154] Disperse the above-mentioned functional microspheres with isocyanate groups of the present invention in a suitable solvent, add diisocyanate and a catalyst, and mix evenly. Further, add the semiconductor catalyst and carry out the reaction, so that the semiconductor catalyst is fixed to the surface of the functional microspheres through covalent bonds. For example, as the feeding amount, the mass ratio of the functional microspheres to the semiconductor catalyst is 20:1 to 1:1.

[0155] In addition, in some specific embodiments, after the semiconductor catalyst is fixed to the surface of the functional microspheres and the product is dried, the obtained product is further subjected to hydrolysis and / or alkaline hydrolysis (such as ammonolysis) to convert the anhydride groups on the microsphere surface into hydrophilic carboxylic acid and / or carboxylate groups.

[0156] Examples of the solvents used for the dispersed functional microspheres include, but are not limited to: ketone solvents such as acetone, methyl ethyl ketone, methyl acetone, 2-pentanone, 3-pentanone, 3-methyl-2-butanone, 2-hexanone, 3-hexanone, 2-methyl-3-pentanone, 3,3-dimethyl-2-butanone, 4-methyl-2-pentanone, 2-heptanone, 3-heptanone, 4-heptanone, 2,4-dimethyl-3-pentanone, 2-octanone, 2,6-dimethyl-4-heptanone, cyclopentanone, cyclohexanone, cycloheptanone, etc.; cyclic ether solvents such as tetrahydrofuran, dioxane, etc.; amide solvents such as N,N-dimethylformamide, N,N-dimethylacetamide; sulfoxide solvents such as dimethyl sulfoxide; pyrrolidone solvents such as N-methylpyrrolidone.

[0157] <<Example>>

[0158] The embodiments of the present invention will be described in detail below in conjunction with the examples. However, those skilled in the art will understand that the following examples are only used to illustrate the present invention and should not be construed as limiting the scope of the present invention. For those not specified in the examples, the operations are carried out under conventional conditions or conditions recommended by the manufacturer. All reagents or instruments not specified by the manufacturer can be obtained as conventional products through commercial purchase.

[0159] <Example 1>

[0160] (1) Preparation of polymer microspheres

[0161] First, 0.582 g of maleimide (6 mmol), 0.24 g of maleic anhydride (2.4 mmol), 0.47 g (3.6 mmol) of divinylbenzene, and 0.015 g of azobisisobutyronitrile were dissolved in 24 ml of methyl ethyl ketone, and then 16 ml of n-heptane was added. After ultrasonic dissolution to form a uniform reaction system, nitrogen was introduced to remove oxygen for 10 min. Then it was placed in an oil bath at 75 °C and reacted at a constant temperature for 6 hours to obtain a milky white and uniform solid-liquid dispersion system. After separation, washing, and drying, maleimide / maleic anhydride / divinylbenzene copolymer cross-linked microspheres (polymer microspheres) were obtained (the proportion of maleimide units was 50 mol%, the proportion of maleic anhydride units was 20 mol%, and the proportion of divinylbenzene units was 30 mol%). The yield was 98%. The morphology of the prepared microspheres was observed by a Hitachi S7800 scanning electron microscope as Figure 1 shown.

[0162] (2) Preparation of functional microspheres with isocyanate groups on the surface

[0163] Disperse 0.2 g of the polymer microspheres prepared in step (1) into 30 ml of N,N-dimethylformamide, add 0.16 g of hexamethylene diisocyanate and 2.94 μL (1.5%) of tin octoate catalyst, and react at 75 °C under stirring conditions for 3 h. After separation, washing, and drying, functional cross-linked microspheres with isocyanate groups on the surface are obtained.

[0164] (3) Preparation of TiO2-supported catalyst

[0165] Disperse 0.1 g of the functional microspheres with isocyanate groups on the surface prepared in step (2) into 20 ml of N,N-dimethylformamide, place it in an oil bath at a constant temperature of 75 °C. Disperse 0.04 g of TiO2 nanoparticles into 20 ml of N,N-dimethylformamide, and ultrasonicate for 2 hours to disperse the TiO2 nanoparticles evenly in the solvent. Add 20 ml of the TiO2 nanoparticle dispersion to the functional microsphere dispersion dropwise, and react under stirring conditions for 3 h. After separation, washing, and drying, a TiO2-supported catalyst is obtained, and the loading rate is 95% (i.e., 95 mol% of the isocyanate groups on the surface of the functional microspheres are connected with semiconductor catalysts).

[0166] Furthermore, disperse the TiO2-supported catalyst into a 0.5% sodium carbonate solution, stir at room temperature for one hour, then separate and dry to obtain a TiO2-supported catalyst with carboxylate groups formed on the surface anhydride groups as sodium carboxylate.

[0167] In addition, characterize the chemical structures of the polymer microspheres, functional microspheres, and TiO2-supported catalyst by a Nicolet Nexus 670 Fourier transform infrared spectrometer as Figure 2 shown.

[0168] (4) Taking the catalytic degradation of dye wastewater containing methylene blue as an example, test the degradation efficiency of the TiO2-supported catalyst.

[0169] Disperse 6 mg of the supported catalyst prepared in step (3) into 30 ml of a methylene blue solution with a concentration of 30 mg / L, place the dispersion in a dark room and stir for 30 minutes to reach adsorption equilibrium, then place it in a 25 w ultraviolet lamp box, take samples every 10 minutes, and irradiate for a total of 90 min. Separate the catalyst from the water by centrifugation, and test the content of the remaining dye in the water by a HITACHI U-3900 / 3900H ultraviolet spectrophotometer. The results show that the dye degradation rate is 100% after 90 minutes of ultraviolet light irradiation.

[0170] Figure 4 To obtain the ultraviolet spectrum of the TiO2-supported catalyst degrading the methylene blue solution at different times.

[0171] <Example 2>

[0172] Except for using maleimide, maleic anhydride, divinylbenzene, and styrene (the proportion of maleimide units is 50 mol%, the proportion of maleic anhydride units is 20 mol%, the proportion of divinylbenzene units is 15 mol%, and the proportion of styrene units is 15 mol%) to prepare polymer microspheres, polymer microspheres, functional microspheres, and supported catalysts were prepared in the same manner as in Example 1, and the performance of the supported catalyst was evaluated in the same manner as in Example 1.

[0173] The results were as follows: The yield of the prepared maleimide / maleic anhydride / divinylbenzene / styrene copolymer cross-linked microspheres (polymer microspheres) was 95%, and the loading rate was 89% because TiO2 was slightly agglomerated. When catalytically degrading dye wastewater containing methylene blue, the dye degradation rate after 90 minutes of ultraviolet light irradiation was 96%.

[0174] <Example 3>

[0175] Except for using maleimide, maleic anhydride, and styrene (the proportion of maleimide units is 50 mol%, the proportion of maleic anhydride units is 20 mol%, and the proportion of styrene units is 30 mol%) to prepare polymer microspheres, polymer microspheres, functional microspheres, and supported catalysts were prepared in the same manner as in Example 1, and the performance of the supported catalyst was evaluated in the same manner as in Example 1.

[0176] The results were as follows: The yield of the prepared maleimide / maleic anhydride / styrene terpolymer cross-linked microspheres was 95%, and the loading rate was 85% because TiO2 was slightly agglomerated. When catalytically degrading dye wastewater containing methylene blue, the dye degradation rate after 90 minutes of ultraviolet light irradiation was 94%.

[0177] <Example 3>

[0178] Except for using only maleimide and divinylbenzene as monomers to prepare polymer microspheres (the proportion of maleimide units is 50 mol%, and the proportion of divinylbenzene units is 50 mol%) and using ethyl acetate as the solvent when preparing polymer microspheres, polymer microspheres, functional microspheres, and supported catalysts were prepared in the same manner as in Example 1, and the performance of the supported catalyst was evaluated in the same manner as in Example 1.

[0179] The results were as follows: The yield of the prepared maleimide cross-linked microspheres (polymer microspheres) was 96%, and the TiO2 loading rate was 95%. When catalytically degrading dye wastewater containing methylene blue, the dye degradation rate after 90 minutes of ultraviolet light irradiation was 89%.

[0180] It should be noted that since wastewater is used as the detection object, the degradation rate in Example 3 is lower than that in Example 1.

[0181] <Example 4>

[0182] Except for using only maleimide as the monomer to prepare polymer microspheres, using ethyl acetate as the solvent for preparing polymer microspheres, and using methyl ethyl ketone as the dispersion medium for preparing functional microspheres and supported catalysts, polymer microspheres, functional microspheres and supported catalysts are prepared in the same manner as in Example 1, and the performance of the supported catalyst is evaluated in the same manner as in Example 1.

[0183] The results are as follows: the yield of the prepared maleimide polymer microspheres (polymer microspheres) is 89%, the TiO2 loading rate is 85%, and when catalytically degrading dye wastewater containing methylene blue, the dye degradation rate after 90 minutes of ultraviolet light irradiation is 92%.

[0184] <Example 5>

[0185] Except for using maleimide and styrene to prepare polymer microspheres (the proportion of maleimide units is 50 mol%, and the proportion of styrene units is 50 mol%), polymer microspheres, functional microspheres and supported catalysts are prepared in the same manner as in Example 1, and the performance of the supported catalyst is evaluated in the same manner as in Example 1.

[0186] The results are as follows: the yield of the prepared maleimide / styrene copolymer microspheres (polymer microspheres) is 95%, the TiO2 loading rate is 78%, and when catalytically degrading dye wastewater containing methylene blue, the dye degradation rate after 90 minutes of ultraviolet light irradiation is 80%.

[0187] <Comparative Example 1>

[0188] Except for changing the feed ratio of the monomers so that the proportion of maleimide units in the obtained polymer microspheres is 10 mol%, the proportion of maleic anhydride units is 60 mol%, and the proportion of divinylbenzene units is 30 mol%, polymer microspheres, functional microspheres and supported catalysts are prepared in the same manner as in Example 1, and the performance of the supported catalyst is evaluated in the same manner as in Example 1.

[0189] The results are as follows: the yield of the prepared maleimide / maleic anhydride / divinylbenzene crosslinked microspheres (polymer microspheres) is 95%. Unexpectedly, a large amount of TiO2 agglomerates, the loading rate is 48%, and when catalytically degrading dye wastewater containing methylene blue, the dye degradation rate after 90 minutes of ultraviolet light irradiation is 49%.

[0190] It should be noted that although the technical solutions of the present invention are introduced by specific examples, those skilled in the art can understand that the present invention should not be limited thereto.

[0191] The embodiments of the present invention have been described above. The above description is exemplary, not exhaustive, and is not limited to the disclosed embodiments. Many modifications and variations are obvious to those of ordinary skill in the art without departing from the scope and spirit of the described embodiments. The choice of terms used herein is intended to best explain the principles of the embodiments, practical applications, or improvements to technologies in the market, or to enable other ordinary skilled persons in the art to understand the embodiments disclosed herein.

Claims

1. A polymer microsphere, characterized in that, The polymer microspheres are obtained by polymerizing only the monomer represented by formula (2), an optional unsaturated dicarboxylic anhydride monomer, and an optional monomer having two or more carbon-carbon double bonds by self-stabilizing precipitation polymerization method. In formula (2), R4 and R5 each independently represent a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, or an aryl group having 6 to 12 carbon atoms. With respect to the entire polymer microspheres, the ratio of the unit based on the monomer represented by formula (2) is 20 mol% or more.

2. The polymer microspheres according to claim 1, characterized in that, The polymer microspheres are obtained by polymerizing only the monomer represented by formula (2) and an optional monomer having two or more carbon-carbon double bonds. With respect to the entire polymer microspheres, the ratio of the unit based on the monomer represented by formula (2) is 45 mol% or more.

3. The polymer microspheres according to claim 1, characterized in that, The polymer microspheres are obtained by polymerizing only the monomer represented by formula (2), an unsaturated dicarboxylic anhydride monomer, and an optional monomer having two or more carbon-carbon double bonds. With respect to the entire polymer microspheres, the ratio of the unit based on the monomer represented by formula (2) is 20 mol% or more and 90 mol% or less.

4. The polymer microspheres according to claim 3, characterized in that, In the polymer microspheres, the molar ratio of the unit based on the monomer represented by formula (2) to the unit based on the unsaturated dicarboxylic anhydride monomer is 1 / 5 to 5 / 1.

5. The polymer microspheres according to any one of claims 1 to 4, characterized in that, The average particle diameter of the polymer microspheres is 0.1 μm to 2 μm.

6. A functional microsphere with an isocyanate group, characterized in that, The functional microspheres are obtained by reacting the active hydrogen atoms on the surface of the polymer microspheres with a diisocyanate compound. The polymer microspheres are obtained by polymerizing at least one monomer selected from the monomer represented by formula (1) and the monomer represented by formula (2), an optional unsaturated dicarboxylic anhydride monomer, and an optional monomer having two or more carbon-carbon double bonds by self-stabilizing precipitation polymerization method. In formula (1), R1 is a hydrogen atom or a methyl group, R2 and R3 each independently represent a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, or an aryl group having 6 to 12 carbon atoms, and at least one of R2 and R3 is a hydrogen atom. In formula (2), R4 and R5 each independently represent a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, or an aryl group having 6 to 12 carbon atoms. With respect to the entire polymer microspheres, the ratio of the unit based on at least one monomer selected from the monomer represented by formula (1) and the monomer represented by formula (2) is 20 mol% or more.

7. The functional microspheres with isocyanate groups according to claim 6, characterized in that, The polymer microspheres are obtained by polymerizing at least one monomer selected from the monomer represented by formula (1) and the monomer represented by formula (2) and an optional monomer having two or more carbon-carbon double bonds, without using an unsaturated dicarboxylic anhydride monomer. With respect to the entire polymer microspheres, the ratio of the unit based on at least one monomer selected from the monomer represented by formula (1) and the monomer represented by formula (2) is 45 mol% or more.

8. The functional microspheres with isocyanate groups according to claim 7, characterized in that, The polymer microspheres are obtained by polymerizing only at least one monomer selected from the monomer represented by formula (1) and the monomer represented by formula (2), or The polymer microspheres are obtained by polymerizing only at least one monomer selected from the monomer represented by formula (1) and the monomer represented by formula (2) and a monomer having two or more carbon-carbon double bonds.

9. The functional microspheres with isocyanate groups according to claim 6, characterized in that, The polymer microspheres are obtained by polymerizing at least one monomer selected from the monomers represented by formula (1) and the monomers represented by formula (2), an unsaturated dicarboxylic anhydride monomer, and optionally a monomer having two or more carbon-carbon double bonds. Relative to the entire polymer microspheres, the ratio of the units based on at least one monomer selected from the monomers represented by formula (1) and the monomers represented by formula (2) is 20 mol% or more and 90 mol% or less.

10. The functional microspheres with isocyanate groups according to claim 9, characterized in that, In the polymer microspheres, the molar ratio of the units based on at least one monomer selected from the monomers represented by formula (1) and the monomers represented by formula (2) to the units based on the unsaturated dicarboxylic anhydride monomer is 1 / 5 to 5 / 1.

11. The functional microspheres with isocyanate groups according to claim 9, characterized in that, The polymer microspheres are obtained by polymerizing only at least one monomer selected from the monomers represented by formula (1) and the monomers represented by formula (2) and an unsaturated dicarboxylic anhydride monomer, or The polymer microspheres are obtained by polymerizing only at least one monomer selected from the monomers represented by formula (1) and the monomers represented by formula (2), an unsaturated dicarboxylic anhydride monomer, and a monomer having two or more carbon-carbon double bonds.

12. The functional microspheres with isocyanate groups according to claim 6, characterized in that, The average particle size of the polymer microspheres is 0.1 μm to 2 μm.

13. The functional microspheres with isocyanate groups according to claim 6, characterized in that, The active hydrogen atoms are derived from the units based on at least one monomer selected from the monomers represented by formula (1) and the monomers represented by formula (2) on the surface of the polymer microspheres; 20 mol% or more of all of the units based on at least one monomer selected from the monomers represented by formula (1) and the monomers represented by formula (2) on the surface of the polymer microspheres react with the diisocyanate compound.

14. A polymer-supported catalyst, characterized in that, The polymer-supported catalyst is obtained by reacting the isocyanate groups on the surface of the functional microspheres with isocyanate groups according to any one of claims 6 to 13 with a semiconductor catalyst.

15. The polymer-supported catalyst according to claim 14, wherein, The semiconductor catalyst is at least one selected from a single-metal semiconductor catalyst and a composite semiconductor catalyst containing two or more metals. The single-metal semiconductor catalyst is at least one selected from ZnO, NiO, Cr2O3, MnO2, MoO3, V2O5, Fe3O4, TiO2, C3N4, BiOBr, CdS, ZnS; the composite semiconductor catalyst is at least one selected from a copper-based semiconductor catalyst, a silver-based semiconductor catalyst, a tungsten-based semiconductor catalyst, a bismuth-based semiconductor catalyst, a tin-based semiconductor catalyst, an indium-based semiconductor catalyst.

16. The polymer-supported catalyst according to claim 14 or 15, characterized in that, The surface of the polymer-supported catalyst further has a carboxylic acid group and / or a carboxylate group.

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