289 results about "Graft polymer" patented technology

The invention relates to the field of civil engineering waterproof materials, in particular to a nano bentonite-polymer composite material with high salt tolerance and a preparation method thereof, and the nano bentonite-polymer composite material is especially suitable for a sodium-based bentonite waterproof blanket in a saline soil area or a marine environment, and the preparation method comprises the following steps: (1) preparing nano bentonite lamellar colloidal dispersion liquid; (2) introducing and mixing an electrostatic screening agent and a polymerizable monomer; (3) carrying out in-situ free radical polymerization reaction; and (4) post-treatment and finished product preparation. By constructing a three-dimensional interpenetrating hierarchical structure composed of a covalent grafted polymer network, a physically anchored electrostatic screening agent and a stripped bentonite nanosheet layer, effective protection of a bentonite core anti-seepage unit is realized, so that the adaptability and long-term stability of the material under a complex water quality condition are remarkably improved.

The invention provides a modified chitosan flocculant for slime water treatment. The modified chitosan flocculant is prepared from the following raw materials: chitosan, dimethyl diallyl ammonium chloride, acrylamide, acetic acid and potassium persulfate. The invention also provides a preparation method of the modified chitosan flocculant for slime water treatment. The preparation method comprises the following steps: dissolving chitosan in a dilute acetic acid solution with the mass concentration of 60%, and stirring; adding acrylamide and dimethyl propyl chloride cyclic amine into the mixed solution, uniformly stirring, adding a potassium persulfate solution with the mass concentration of 4%, and introducing nitrogen for 20 minutes; then carrying out microwave reaction, and cooling to room temperature after the reaction is completed; adding absolute ethyl alcohol, centrifuging for 10 minutes, taking out, and continuously soaking in absolute ethyl alcohol for 12 hours, so as to obtain a final insoluble substance which is a graft polymer CS-g-ADM; and drying the polymer in a drying box at 105 DEG C until no weight loss occurs, and then grinding and storing. The flocculating agent disclosed by the invention has relatively good flocculability.

The invention provides an automotive bacteriostatic polypropylene-based wood-plastic composite material and a preparation method thereof, the automotive bacteriostatic wood-plastic composite material comprises the following raw materials by mass: 90 parts of a polypropylene matrix, 20-40 parts of modified plant fiber, 5-20 parts of an inorganic filler, 1-3 parts of a lubricant, and 0.1-2 parts of an antioxidant; the modified plant fiber comprises plant fiber grafted with a graft polymer and loaded with a pyridine antibacterial agent, and the graft polymer comprises a polyunsaturated carboxylic acid chain segment and a polypropylene chain segment. The modified plant fiber has good compatibility with a polypropylene matrix and can be used for preparing a wood-plastic composite material, so that the mechanical property, the interface stability and the long-term antibacterial property of the composite material are remarkably improved.

The invention discloses an insulating heat-conducting glass fiber reinforced polyphenylene sulfide composite material and a preparation method thereof. The composite material comprises the following raw material components: 30-50 parts by mass of polyphenylene sulfide, 10-20 parts by mass of glass fiber, 30-50 parts by mass of a heat-conducting filler, 5-10 parts by mass of a compatilizer and 0.3-1 part by mass of a coupling agent, and the heat-conducting filler is selected from one or more of graphite, silicon carbide, aluminum oxide, magnesium oxide, aluminum nitride and hexagonal boron nitride; the compatilizer is selected from a glycidyl methacrylate graft polymer. The polyphenylene sulfide composite material prepared by the preparation method disclosed by the invention has high insulativity, high thermal conductivity and good mechanical properties.

An aqueous pretreatment liquid for inkjet printing comprises resin particles having an average diameter of 1 [mu] m or less and comprising a first polymer and a second polymer, and a fixing agent, the first polymer is a polymer selected from the group consisting of polyureas, polyurethanes, polyamides, polyesters, polycarbonates, polysulfonamides, polyamides, polysulfonamides, melamine-based polymers, silica-based sol-gel polymers, and combinations thereof, and the second polymer is a polyoxyalkylene graft polymer obtained by polycondensation or addition polymerization, the polyoxyalkylene graft has a number average chain length of 20 or more oxyalkylene units. The pre-treatment liquid is useful for inkjet printing on packaging materials such as cardboard or corrugated cardboard.

The invention discloses a hydrogen energy fuel cell catalyst carrier based on a graphene graft polymer, which is characterized in that two-dimensional graphene is used as a substrate, the surface of the two-dimensional graphene is modified with an oxygen-containing functional group, and a functional polymer branch chain containing nitrogen, sulfur or phosphorus heteroatoms is covalently grafted to form a local three-dimensional network winding structure; the carrier is loaded with platinum, palladium, ruthenium and other metal or alloy nanoparticles, the particle size is 2-8 nm, the loading capacity is 10%-40%, and the particles are anchored to polymer functional sites or reduced in situ to a graphene defect area through coordination. A polymer branch chain has pH responsiveness and can adjust the local proton transmission efficiency; the grafting density is 3-15 grafting points per 100 carbon atoms, so that high dispersion and stable anchoring of metal particles are effectively realized; the specific surface area of the carrier is 400-800m < 2 > / g, the electrochemical active area is not less than 80m < 2 > / g, and the activity retention rate is greater than 80% after 5000 circles of accelerated durability tests. The activity, the stability and the proton conduction performance of the catalyst are remarkably improved, and the catalyst is suitable for high-performance fuel cells.

The invention provides a soap-free high-molecular agglomerant as well as a preparation method and application thereof. The soap-free high-molecular agglomerant contains an oligomer, the molecular structure of the oligomer contains a hydrophilic group and an oleophylic group; the weight-average molecular weight of the oligomer is 300 to 5000; the hydrophilic group comprises an amide group and / or carboxyl. According to the invention, the soap-free high-molecular agglomerant has a good agglomeration effect, large-particle-size polybutadiene latex can be obtained through agglomeration, and the high-molecular agglomerant does not contain an emulsifier, so that the introduction of excessive emulsifier in the preparation process of an ABS graft polymer is avoided; the ABS latex coagulation efficiency is improved, the impact resistance of the ABS resin is improved, and the yellow index of the ABS resin is reduced.

The present invention relates to an agrochemical composition comprising an agrochemical active ingredient and a cleaning composition comprising a cleaning additive, each further comprising at least one novel graft polymer comprising a polymer main chain (A) as a graft matrix having grafted polymer side chains (B) thereon. The polymer side chain (B) is obtainable by polymerization of at least one vinyl ester monomer (B1) and optionally a further monomer. The polymer backbone (A) comprises a polyalkylene oxide-derived moiety and a moiety derived from a lactone and / or a hydroxy acid, which moieties are mixed such that the polymer backbone contains ester functional groups within the polymer chain. The graft polymers of the compositions of the invention have been found to be suitable as dispersants for pesticidal agents in agrochemical compositions, and also suitable in cleaning compositions for improving cleaning properties. In addition, the graft polymer typically exhibits a suitably high degree of biodegradability and thus allows for a more environmentally friendly formulation. The graft polymer itself and its production are also claimed.

The invention belongs to the technical field of environment-friendly materials, and particularly relates to a bamboo-based composite material and a preparation method thereof.The bamboo-based composite material is composed of a biodegradable resin matrix, multi-scale bamboo fiber filler and the like, and the core of the bamboo-based composite material is that micron, submicron and nanometer three-level bamboo fibers are adopted to construct a multi-scale reinforced network, and a nanometer carbon reinforced phase material is adopted for assistance; through a reaction type interface modifier system containing a maleic anhydride grafted polymer and the like, strong chemical bonding of fibers and a resin matrix is achieved, interface compatibility is remarkably improved, the material selects PBS, PBAT, PLA and other matrixes, a plasticizer and a functional auxiliary are combined, excellent biodegradability is kept, meanwhile, high mechanical strength and good processing performance are achieved, and the material is suitable for industrial production. The composite material is an ideal green and environment-friendly material, the material still keeps excellent mechanical properties when the total amount of the bamboo fibers reaches 60 parts through the synergistic effect of the three-scale fibers, and the tensile strength can reach 50 MPa to 65 MPa and is improved by 180% or above under the same filling amount compared with the prior art.

The invention relates to preparation of hydrolyzed keratin capable of maintaining hair and application of the hydrolyzed keratin in shampoo. The shampoo capable of maintaining the hair and the keratin is prepared by compounding a surfactant, a modified silicone oil graft polymer, the hydrolyzed keratin and polydimethylsiloxane. According to the modified silicone oil graft polymer, hydrophilic sodium acrylate and hydrophobic N-vinyl pyrrolidone and acrylic ester are introduced into vinyl silicone oil, and N-vinyl pyrrolidone and acrylic ester can be adsorbed on the inner side of the hair surface; sodium acrylate with hydrophilicity is located on the outer side of the surface of the hair due to electrostatic repulsion between the negatively-charged hair and generates hydration with water molecules on the surface of the hair to form a water shell protection layer, so that the sodium acrylate can be more uniformly distributed on the hair to form an effective protection film, and during washing, the water washing property is greatly enhanced by the hydrophilic part of the sodium acrylate; non-specific deposition and residues in a scalp area are remarkably reduced, and the washed hair can be moisturized and lubricated.

The invention relates to the field of 3D printing, and particularly discloses high-toughness and high-tack polyester for 3D printing and a preparation method thereof.The polyester is prepared from, by mass, 0.2-3% of antioxidant, 0.1-3% of dispersing agent and the balance matrix resin; the matrix resin comprises the following raw materials: binary acid, dihydric alcohol, a graft polymer, a catalyst and a protective agent. According to the polyester, a graft polymer containing active groups such as hydroxyl is introduced into matrix resin, so that the melt uniformity of a whole blending system is improved, the interface energy is reduced, a polyester molecular chain is easier to cross an interlayer interface to move and entangle, stronger physical connection is formed, layers are easier to bond and do not crack during 3D printing, and the 3D printing performance is improved. The adhesive has excellent interlayer adhesive force, meets the application requirement of high additional value in the field of industrial-grade 3D printing, and can be used in the fields of outdoor artware, construction industry, aerospace, medical instruments and the like.

The invention discloses a graft polymer and a preparation method and application thereof.The graft polymer comprises a structural unit I from graphene oxide, a structural unit II from a monomer A and a structural unit III from a monomer B. The value of the carbon element and the oxygen element of the graphene oxide is not larger than 2.5; the monomer A is a monomer containing a sulfonic acid group; the monomer B is a propenyl monomer containing a rigid group; the viscosity average molecular weight of the graft polymer is 75,000 to 120,000. The graft polymer disclosed by the invention can be used as an ultrahigh-temperature salt-resistant shear strength improving agent for water-based drilling fluid, the temperature resistance can reach 240 DEG C or above, the salt resistance can reach saturation, and the influence on the plastic viscosity of the drilling fluid is less while the shearing force of the drilling fluid is increased.

The invention relates to the technical field of immunochromatography, in particular to time-resolved fluorescent microspheres, a preparation method and application of the time-resolved fluorescent microspheres in PSP / CRP / MxA quantitative detection immunochromatography test strip, and the preparation method of the time-resolved fluorescent microspheres comprises the following steps: 1) preparing surface aminated polystyrene microspheres; (2) carrying out glutaraldehyde crosslinking and 1, 10-phenanthroline-5-amino combination; 3) grafting a rare earth fluorescent dye on the surface; and 4) coating a polymer shell layer and modifying carboxyl. According to the invention, through a dual fixation strategy of surface grafting and polymer coating, the time-resolved fluorescent dye is confined to a functional region between the surface of the microsphere and a polymer shell layer, diffusion and leakage of dye molecules to the external environment are blocked, and the problem of dye shedding of traditional fluorescent microspheres is solved; the polymer shell layer can effectively isolate external ultraviolet light, oxygen and other corrosive factors, reduce photooxidative degradation and non-radiative transition loss of fluorescent molecules, and improve the light stability and fluorescent lifetime of the fluorescent molecules.

The invention belongs to an insulating material, relates to a polypropylene-based insulating material, and in particular relates to a high-temperature-resistant intrinsic self-recovery polypropylene insulating material as well as a preparation method and application thereof. The material is formed by blending a polypropylene grafting material and an ethylene-tetrafluoroethylene copolymer grafting material according to a mass ratio of 6.0: 4.0-9.5: 0.5, wherein the PP graft material comprises a PP graft polymer and an antioxidant, and the PP graft polymer is a graft polymer formed by grafting 4-propenyloxy-2-hydroxybenzophenone to polypropylene; the ETFE graft material comprises an ETFE graft polymer and an antioxidant, and the ETFE graft polymer is a graft polymer of glycerol grafted ethylene-tetrafluoroethylene copolymer. On the basis of keeping the original excellent performance of polypropylene, the polypropylene has higher heat resistance and self-recovery capability through a grafting modification technical means.

The invention discloses a graphene oxide grafting modification method and a product thereof, and relates to the technical field of material modification. According to the method disclosed by the invention, the principle that a grafting reaction can be carried out between hydroxyl and carboxyl contained in graphene oxide and an ester group contained in a polyester polymer is utilized, so that the graphene oxide can be subjected to an efficient grafting reaction with the polyester polymer under a relatively mild condition; therefore, the polyester polymer can be directly grafted onto the graphene oxide, and the compatibility between the graphene oxide and the polyester polymer is remarkably improved; the method is simple in reaction step, controllable in process, mild in condition and high in grafting rate, no by-product is generated in the reaction process, impurity removal treatment does not need to be carried out on the reaction product, and regulation and control on the performance of the polyester polymer can be realized by directly regulating and controlling the variety and the structure of the grafted polymer according to the variety of a polyester polymer material needing to be enhanced; the method is suitable for large-scale application in graphene oxide reinforced modified polyester polymers.

The invention belongs to the technical field of lithium battery negative electrode interface modification, and discloses a multifunctional two-dimensional hybrid polymer artificial SEI membrane and a preparation method and application thereof. Comprising a compound as shown in a formula I, a polymer brush is grafted on the surface of brominated graphene oxide through atom transfer radical polymerization (ATRP), monomers of the polymer brush are carboxyl-containing monomers and fluorine-containing monomers, and the artificial SEI membrane is constructed through spin coating and membrane forming. The multifunctional artificial SEI film provided by the invention has the structural and functional characteristics of two-dimensional graphene oxide and in-situ reaction type macromolecules, the mechanical property of the film can be remarkably improved by an accumulated two-dimensional skeleton, the Young modulus can reach 3.7 GPa, the growth of lithium dendrites is inhibited, and the performance of the film is improved. Functional groups (carboxyl and fluoro) in the hybrid polymer brush and lithium metal are subjected to in-situ chemical reaction, so that the electrode interface stability and the lithium deposition uniformity are improved, and the hybrid polymer brush has wide application prospects in the field of lithium batteries.

The invention discloses anti-aging modified asphalt and a preparation method thereof, and relates to the technical field of building materials, the anti-aging modified asphalt comprises the following specific components: base petroleum asphalt, a thermoplastic elastomer, an anti-stripping agent, an ultraviolet absorbent, an antioxidant and a softening agent; the additive comprises a nano montmorillonite modifier, a phosphate type flame-retardant anti-aging agent, a bio-based polyphenol antioxidant, a siloxane graft polymer and a carbon quantum dot light stabilizer; the preparation is performed based on the components. On the basis of a traditional modification system, multiple additives are cooperatively introduced, and a composite system with multiple shielding, free radical scavenging, weather-proof protection and macromolecule enhancement functions is constructed. According to the modification system, the high-temperature stability, the low-temperature flexibility and the water resistance of the asphalt material are remarkably improved on the macroscopic level, and meanwhile the aging process of the material is greatly delayed through the nanoscale barrier effect, the long-acting anti-oxidation mechanism and the light stabilization mechanism on the microscopic level.

To provide a toner that achieves both low-temperature fixation and storage stability in high-temperature environments. [Solution] A toner containing a graft polymer resin including a polyolefin resin and a styrene-based resin, a polyester resin, and a release agent, wherein when the toner heated to 50°C is measured by FTIR-ATR (total internal reflection absorption infrared spectroscopy), the peak intensity derived from the release agent is set to Wk-50 and the peak intensity derived from the polyester resin is set to RK-50; when the toner heated to 70°C is measured by FTIR-ATR, the peak intensity derived from the release agent is set to Wk-70 and the peak intensity derived from the polyester resin is set to RK-70; and when the toner heated to 90°C is measured by FTIR-ATR, the peak intensity derived from the release agent is set to Wk-90 and the peak intensity derived from the polyester resin is set to RK-90, the toner satisfies the following formulas (1) and (2). (Wk-70 / RK-70) / (Wk-50 / RK-50)≦1.1···(1) 1.5≦(Wk-90 / RK-90) / (Wk-50 / RK-50) (2)

The present invention relates to novel graft polymers comprising a polymer main chain (A) as a graft matrix having grafted polymer side chains (B) thereon. The polymer side chains (B) are obtainable by polymerization of at least one vinyl ester monomer (B1), optionally at least one nitrogen-containing monomer (B2), optionally a further monomer (B3). The polymer backbone (A) comprises a polyalkylene oxide-derived moiety and a moiety derived from a lactone and / or a hydroxy acid, which moieties are mixed such that the polymer backbone contains ester functional groups within the polymer chain. The invention further relates to a method for obtaining such a graft polymer, preferably by free-radical polymerization. The invention also relates to the use of such graft polymers, for example in fabrics and home care products. Also claimed are compositions and products containing such graft polymers, such as fabrics and home care products.

The present invention relates to a thermoplastic resin composition including: a base resin including a diene-based graft polymer and a vinyl-based non-grafted polymer including an aromatic vinyl-based monomer unit and a vinyl cyanide-based monomer unit; and an additive including an olefin-based non-grafted polymer including an olefin-based monomer unit, a (meth)acrylate-based monomer unit, and a maleic acid-based monomer unit.

A resin composition includes a coloring material, a resin, and a solvent. The resin includes a graft polymer which has a main chain including a molecular chain having a structure derived from a compound having an ethylenically unsaturated bond-containing group and a graft chain, and the graft chain includes a repeating unit p1 having an oxetane group. The resin composition may be employed in a film formed of the resin composition; an optical filter; a solid-state imaging element; and an image display device.

The invention belongs to the technical field of sewage treatment, and particularly discloses a sludge deep dehydration conditioner based on a tannic acid graft polymer as well as a synthesis method and industrial application of the sludge deep dehydration conditioner. The conditioner is a novel derivative formed by grafting tannic acid to a main chain of a synthetic polymer or a natural polymer in a chemical bonding mode, the molecular structure of the conditioner comprises high-density cation active sites and three-dimensional net-shaped chelating groups, and the conditioner has the strong current neutralizing capacity and the multi-level adsorption characteristic. The derivative is realized through an oriented synthesis technology for the first time, is innovatively applied to the field of sludge dewatering, can efficiently destroy a sludge extracellular polymer structure, and remarkably improves the bound water release efficiency. According to the conditioner disclosed by the invention, through accurate design of a molecular structure, the sludge dewatering rate is increased by 20% or above while the dosage of a medicament is reduced, and the grafting rate and charge density parameters form core protection characteristics, so that the technical bottleneck of a traditional flocculating agent in deep sludge dewatering is broken through.

The application provides a carbon nanotube grafted polymer nano plugging agent, a preparation method thereof and a prepared drilling fluid, and the preparation method comprises the following steps: S1, reacting acrylic acid and amino functionalized multi-walled carbon nanotubes in a mass ratio of 1:0.1-0.2 to generate acrylic acid modified carbon nanotubes; and S2, performing a copolymerization reaction on acrylamide, the acrylic acid modified carbon nanotubes and octadecyl dimethyl allyl ammonium chloride in a mass ratio of 25:0.2-0.8:1.2-2.0 to obtain the carbon nanotube grafted polymer nano plugging agent. The carbon nanotube grafted polymer nano plugging agent comprises an amide group, a quaternary ammonium salt structure and an amino group, enhances the micro-nano plugging capacity of the plugging agent, enhances the inhibition capacity of the plugging agent to the hydration expansion and dispersion of formation mud shale, and has good temperature resistance, salt resistance and dispersion stability.

To provide an electrophotographic photoreceptor, process cartridge, and image forming apparatus that offer excellent wear resistance and can suppress image blurring. [Solution] The electrophotographic photoreceptor comprises a conductive substrate, a photosensitive layer, and a protective layer. The photosensitive layer is provided on the conductive substrate. The protective layer is provided on the photosensitive layer. The protective layer has a substrate made of a graft polymer having the composition of a UV (ultraviolet) curable polyfunctional monomer, a photopolymerization initiator, and a photoreactive group-containing substance, n-type conductive fine particles dispersed in the substrate, and metal oxide fine particles dispersed in the substrate, and has a Martens hardness of 400 N / mm². 2 The above and the volume resistivity is 1.0 × 10⁻⁶ 10 It is greater than or equal to Ω·cm.

The invention belongs to the technical field of heavy oil sewage biochemical treatment, and discloses a heavy activated sludge process anaerobe nutritional agent and application thereof, the nutritional agent comprises a component A and a component B, the component A is citric acid monohydrate, the content of the component A is 114-125g / L; the component B is ammonium phosphate with the content of 57-69g / L; the component C is glycerol with the content of 185 to 196g / L; the component D is 35 to 42g / L of starch-acrylamide graft polymer; the component V is a mixture of alpha-transglucosidase and alpha-amylase; the content is 1.3-1.5 g / L, the component is coal powder granular active carbon, and the solvent is water. The components of the preparation are non-toxic components, the organic components are degradable components, the preparation belongs to an environment-friendly product, the main components are stabilized in the form of comprehensive technologies such as net crosslinking and activated carbon adsorption, the effects of the main components are not affected, production is convenient and fast, the preparation is stable, reproduction of exopolysaccharide producing bacteria is facilitated, and meanwhile the efficiency of various microorganisms can be improved in a targeted mode.

This invention relates to edge adhesive for positive electrode sheets, coating compositions, positive electrode sheets, and batteries, belonging to the field of lithium-ion battery technology. The technical problem solved by this invention is to provide an edge adhesive for positive electrode sheets. This edge adhesive comprises an oil-soluble polymer with a flexible polymer as the main chain and a polar polymer as the branch chain. The edge adhesive of this invention has good adhesion to metal foils and a hot-pressing bonding effect on olefin separators. Without changing existing processes and equipment, the edge adhesive composition is simultaneously applied to the edge of the positive electrode sheet during coating, completely avoiding burrs and powder shedding. In the subsequent hot-pressing and shaping of the battery cell, this coating composition can firmly bond the electrode sheet and separator together, maintaining the flatness of the electrode assembly and preventing electrode misalignment during battery vibration, which can reduce the risk of short circuits in the battery cell and improve the overall safety and electrochemical performance of the battery.

The invention provides a composition for treating diabetes as well as a preparation method and application thereof, and belongs to the technical field of medicines. The preparation method comprises the following steps: loading berberine on a milk exosome to prepare a berberine-loaded exosome, loading liraglutide on phycobiliprotein to prepare liraglutide-loaded phycobiliprotein, preparing PEG-COOH, reacting with chitosan to prepare a chitosan-polyethylene glycol graft polymer, embedding the berberine-loaded exosome and the liraglutide-loaded phycobiliprotein, and cross-linking to prepare microspheres. And centrifuging, washing and drying to obtain the composition for treating diabetes. According to the prepared composition for treating diabetes, the loading capacity of the medicine is greatly improved, the carrier also has a very good protection effect on islet cells, so that islet cell injury is repaired, normal insulin secretion of islet cells is promoted, the prepared composition can be orally taken, the medicine effect is greatly improved, the compliance of patients is improved, and the preparation method is suitable for clinical application. The bioavailability is high, and safety and non-toxicity are realized.

Embodiments relate to a multilayer structure including an adhesive layer and, in direct contact therewith, a layer forming a support film, in which the adhesive layer includes a polyolefin A and a functionalized polyolefin and has a melting temperature of between 80° C. and 120° C., and in which the support film includes a polyamide graft polymer and has a flow temperature of greater than 160° C. Embodiments also relate to a process for manufacturing same, to the use of such a multilayer structure for manufacturing photovoltaic modules and to a process for manufacturing such modules, and also to these photovoltaic modules per se.

The present invention relates to a thermoplastic resin composition comprising: a base resin comprising a recycled resin, a neodiene-based graft polymer, and a neovinyl-based non-graft polymer; and an additive comprising a special pigment and an inorganic oxide in a weight ratio of 1: 1.10 to 10.00.

The present invention provides a novel graft polymer composition which contains a graft polymer of cellulose acetate and a lactone and which achieves both excellent thermoplasticity and suppression of bleed out.　Provided is a polymer composition which contains a graft polymer of cellulose acetate and a lactone, wherein the proportion of a methanol-soluble material of the polymer composition as measured via the method below is in the range of 13-33 mass%. (Method for measuring proportion of methanol-soluble material) Under atmospheric pressure, in a 20°C environment, acetone is dissolved in 144 ml with respect to 24 g of the polymer composition, 1.5 L of methanol is added, and stirring is carried out for 12 hours. A mixture thus obtained is filtered with a PTFE membrane filter having a pore diameter of 1 μm, and a filter residue is collected. The obtained filter residue is put into 0.5 L of methanol again, and stirring is carried out for 1 hour. A mixture thus obtained is filtered with a PTFE membrane filter having a pore diameter of 1 μm, and a filter residue and a filtrate are collected. The obtained filter residue is put into 0.5 L of methanol again, and stirring is carried out for 1 hour. A mixture thus obtained is filtered with a PTFE membrane filter having a pore diameter of 1 μm, and a filter residue and a filtrate are collected. After the pH of the filtrate is confirmed to be 7, the filter residue is added to 1 L of methanol, and stirring is carried out for 12 hours. A mixture thus obtained is filtered with a PTFE membrane filter having a pore diameter of 1μm, and a filter residue is collected. The obtained filter residue is dried at 40°C for 12 hours in a vacuum, and a dry mass is thus obtained. From the dry mass of the polymer composition before purification and the dry mass of the polymer composition after the purification, the proportion of the methanol-soluble material contained in the polymer composition is calculated. Methanol-soluble component of polymer composition = dry mass of polymer composition before purification - dry mass of polymer composition after purification Proportion of methanol-soluble material contained in polymer composition = (mass of methanol-soluble component of polymer composition) / dry mass of polymer composition after purification × 100 (mass%)