2232 results about "Emulsion polymerisation" patented technology

This invention relates to polymeric nanoparticles useful for drug delivery with target molecules bonded to the surface of the particles and having sizes of up to 1000 nm, preferably 1 nm to 400 nm, more preferably 1 nm to 200 nm, that are dispersed homogeneously in aqueous solution. The target drug/target substance is covalently bonded to the novel polymeric nanoparticles to secure them from outer intervention in vivo or cell culture in vitro until they are exposed at the target site within the cell. This invention also relates to microemulsion polymerization techniques useful for preparing the novel nanoparticles.

A method of forming carbon nanotube-filled composites using miniemulsion polymerization. The carbon nanotubes are preferably single-walled carbon nanotubes. The carbon nanotubes are highly dispersed within and associated with the polymer comprising the composite.

The invention relates to a high-sealing polyacrylic ester dispersoid and a preparation method thereof; a multi-element emulsifier system which consists of an anionic emulsifier and a compound non-ionic emulsifier is adopted for controlling the charging process and components of the emulsifier in different polymerization periods, and the room-temperature self-crosslinking high-sealing polyacrylic ester dispersoid is prepared by a semi-continuous seeding emulsion polymerization process. The dispersoid has small particle size, good electrolyte-resistance (calcium ion) stability and high tolerance to various film forming accessory ingredients (various organic solvents with high boiling point). The dispersoid is used as seal coat of water-based wood coating and has good sealing performance to various woods; harmful volatile organic compounds (VOC) such as formaldehyde, and the like sealed against escaping from plates to pollute indoor environment, and the colored compounds such as turpentine, pine oil and tannin and the like are sealed against dissolving out of the plates to pollute pure top coating and white top coating of a water-based wooden ware; and in addition, the dispersoid can be used in water-based leather finishing agents.

The invention relates to a method for preparing a high solid content latent cured polyurethane acrylic acid heterozygous latex and an application thereof. The preparation method comprises the following steps: pre-polymerizing polyester polyalcohol, hydrophilic chain extender and diisocyanate monomer to obtain the polyurethane prepolymer containing a hydrophilic group (carboxyl or sulfo group) and a terminal NCO group; then, neutralizing the polymer into salt and dispersing the salt in water to prepare the polyurethane water dispersoid; finally, using the dispersoid as macro molecular emulsifying agent and reactant to emulsify and disperse the acrylic ester monomer, initiating the polymerization by heating, dropping initiator to perform the latex polymerization, and regulating the pH of the latex by adding a latent curing agent to obtain the high solid content latent cured polyurethane acrylic acid heterozygous latex. The high solid content latent cured polyurethane acrylic acid heterozygous latex has a solid content of above 45%; the storage of the high solid content latent cured polyurethane acrylic acid heterozygous latex is stable; and high hardness film coating can be formed at the room temperature. Compared with acrylic acid latex and polyurethane latex, the high solid content latent cured polyurethane acrylic acid heterozygous latex has better film forming performance, water resistance, alcohol resistance, pollution resistance, dry/wet cleaning resistance and chemical solvent resistance, as well as high hardness.

The invention discloses a Janus particle with double properties and a preparation method thereof. By employing cross-linked polymer colloidal particles as seeds and through a seed emulsion polymerization method, Janus particles with double properties are obtained on the basis of a phase separation mechanism; inorganic, metal and metal oxide compounded Janus particles with electrical, magnetic, optical properties are obtained through functional group modification and composition of function materials and can be used for the material field. The Janus particles have an emulsifying property in organic, inorganic dispersed phases or different organic dispersed phases and meanwhile the Janus particles have a great application prospect in the aspects of self-assembly, superhydrophobicity, nanomotor and the like. The preparation method provided by the invention is easy to operate, has the feasibility of mass production and can adapt to different needs by modification and composition of function materials.

The invention provides a fluorine-silicon modified self-crosslinking acrylic ester emulsion and a preparation method thereof, belonging to the technical field of polymer synthesis. The emulsion is a product formed by organosilicon monomers, fluoride-containing acrylic monomers, (methyl) acrylic monomers and self-crosslinking monomers through core-shell emulsion polymerization. The preparation method adopts a core-shell emulsion polymerization method, thereby ensuring that the fluoride-containing acrylic monomers tend to surface polymerization, and fluorine atoms tend to polymer surface in emulsion film forming process; moreover, the monomers capable of self-crosslinking is added to a shell layer, so as to utilize the crosslinking of the monomers to fixedly limit the migration of the fluorine atoms towards the inside of latex particles, as well as the swing of chains, thereby ensuring that the performances of the fluoride-containing emulsion are completely embodied. The preparation method improves the water resistance, stain resistance, solvent resistance, weather resistance and other comprehensive performances of the emulsion. The fluorine-silicon modified self-crosslinking acrylic ester emulsion prepared through the preparation method can be widely applied to high-grade building paint, industrial paint and wooden ware varnish. Moreover, the preparation method has the characteristics of simple manufacturing process, easy reaction condition control, good emulsion stability and environment-friendly property.

A process for synthesizing the phase-change energy-accumulating microcapsules by emulsion polymerizing method features that the liposoluble organic phase-change material, vinyl or bivinyl monomers, water, non-ionic or anionic surfactant and the persulfate, percarbonate, perborate, hydrogen peroxide, or their redox pair take part is core-shell polymerizing reaction in emulsion to obtain said microcapsules.

A silicone resin-containing emulsion composition is prepared by emulsion polymerizing a solution containing a water-insoluble silanol group-bearing silicone resin and a radical polymerizable vinyl monomer and substantially free of an organic solvent. The emulsion may further contain a film-forming assistant having a boiling point of at least 100 DEG C. and soluble or uniformly dispersible in water. The emulsion can be coated and cured into a film having mar resistance, weather resistance, and chemical resistance.

The invention discloses a preparation method of a polyaniline and molybdenum disulfide intercalated composite material. The preparation method comprises the steps of preparing suspension of graphene molybdenum disulfide from molybdenum disulfide powder through a chemical intercalation process, adding an aniline monomer, an oxidizing agent and organic acid dopants, and implementing in-situ emulsion polymerization to prepare the polyaniline/molybdenum disulfide intercalated composite material. The preparation method is simple and convenient, controllable and environment-friendly; the material is in emulsion or solid powder, and can be formed by coating, deposition, or pressing powder thereof, and other methods; the material is uniform in texture, stable in performance, and excellent in both photoelectrical performance and thermal stability; and the composite material is applicable to the fields of photoelectronic devices such as a secondary battery, a super-capacitor, an electromagnetic shielding device, an antistatic device, a field effect transistor, a sensor, an organic electroluminescence device and the like.

The invention belongs to the technical field of seed emulsion polymerization, relates to a preparation of a high polymer material, and especially relates to a small-particle-size carboxylic styrene-butadiene latex and its preparation method. Technical problems comprising unadjustable particle size, bad mechanical stability, bad chemical stability and the like of latexes in the prior art are solved in the invention. The preparation method which adopts a seed emulsion polymerization technology and adopts butadiene and styrene as monomers comprises the following steps: adding soft water, a seed latex, an electrolyte, a chelating agent and a pH buffering agent; heating; adding functional monomers, unsaturated carboxylic acid, a molecular weight adjustment agent, a composite emulsifier and an initiator; degassing when the conversion rate reaches above 98%; cooling; and synthesizing the carboxylic styrene-butadiene latex. Compared with the prior art, the preparation method of the small-particle-size carboxylic styrene-butadiene latex has the advantages of realization of the adjustment of the particle size of the latex, and simple operation; and compared with present carboxylic styrene-butadiene latexes, the carboxylic styrene-butadiene latex prepared in the invention has the advantages of narrow monodispersion, good fluidity, excellent mechanical stability and excellent chemical stability.

The present invention discloses one kind of nanometer composite silica/acrylate emulsion and its preparation process. The present invention is superior to available technology, and the composite emulsion has dispersed nanometer inorganic silica phase in 0.1-5 % of the total weight of monomers for the acrylate copolymer emulsion. The preparation process includes the surface treatment of nanometer inorganic silica phase, and synthesizing nanometer inorganic phase/polymer emulsion in molecular level compounding through in-situ polymerization process or seed emulsion polymerization process. The composite emulsion of the present invention can form film with doubled tensile strength and breaking elongation. Adding nanometer silica in 0.2 % results in tensile strength of 5.25 MPa and breaking elongation of 1300 %.

An organic siloxane modifier nano-class styrene-acrylate emulsion used for paint or adhesive is prepared from the functional silane monomer with multifunctional vinylalkoxy groups and the monmers of styrene, alkyl methylacrylate, hydroxyalkyl methylacrylate, alkyl acrylate and (methyl) acrylic acid through copolymerization in the manner that under the action of organic silaxane as hydrolysis inhibitor the emulsion polymerizing is inhibited. Its advantages are low content of emulsifier, high content of solid component and storage stability (more than one year), high resistance to weather, dirt, water, chemical solvent and alkali, and high adhesion and tension strength.

The invention discloses a room-temperature self-crosslinking water-soluble polyurethane acrylic resin and a preparation method and an application thereof. The preparation method adopts an in-situ emulsion polymerization method and improves the prior preparation method, introduces tetramethyl benzene dimethylene diisocyanate or 2, 4 methyl cyclohexyl diisocyanate, and dipropylene glycol or neopentyl glycol functioning as chain extendor in raw materials, thereby lowering the viscosity of polyurethane prepolymer, and achieving the purpose of performing the synthetic reaction without organic solvent; oil-soluble evocating agent and water-soluble evocating agent are adopted to together evocate radical copolymerization so that oil-soluble monomer and water-soluble monomer can more effectively perform the radical copolymerization, thereby improving the reaction conversion rate. In addition, the combination of the two evocating agents also leads emulsion in the reaction to keep stable without easily jellifying and layering. The resin can be used for preparing plastics, aluminum foil package compound gel, paper-plastics compound gel, water color ink, water oil polish, water wooden ware paint or water plastic paint.

Preparation of chitosan magnetic microsphere and preparation of immobilized yeast for magnetic microsphere. The invention adopts suspended emulsion polymerization to prepare chitosan magnetic microsphere. The invention immobilize yeast cell to magnetic microsphere by swelling absorption. The inventive chitosan magnetic microsphere has characteristics of both magnetic particle and macromolecular material. Immobilized yeast cell is not discharged out of the system with fermentation broth, so that consumption is avoided, concentration of yeast cell in the fermentor is kept, rate of alcoholic fermentation is enhanced, fermentation time is shorten, resource consumption is reduced, while reducing discharge of waste water, and hardness to process the waste water.

The invention discloses a preparation method and application of internal-external dual cross-linked core-shell structured acrylic acid emulsion. The method employs a multi-step pre-emulsification and polymerization process for seed emulsion to prepare the acrylic acid emulsion and mainly comprises a first step of preparation of seed monomers, a second step of seed emulsion polymerization, a third step of core emulsion polymerization and a fourth step of shell emulsion polymerization; after polymerization is finished, the pH value of the emulsion is adjusted, and adipic dihydrazide is added so as to obtain the internal-external dual cross-linked core-shell structured acrylic acid emulsion. According to the invention, polymerization stability and minimum film-forming temperature of the core-shell structured acrylic acid emulsion prepared in the invention are greatly improved; the acrylic acid emulsion is applied in the field of water-borne wood paints and can improve the cross-linking degree, density and hardness of a paint film and reduce water absorption and a glass transition temperature of the paint film.

The invention provides a cation surface sizing agent and preparation method thereof. Raw materials are as follows by weight percent: 8-17% of styrene, 5-15% of butyl acrylate, 0.5-5% of acrylamide, 0.5-5% of N-hydroxymethyl acrylamide, 1-5% of methyl acryloyl ethyl trimethylammonium chloride, 2-8% of starch, 0.001-0.003% of amylase, 0.2-0.7% of organic acid, 0.2-0.8% of emulsifier, 1-5% of 27% hydrogen peroxide, 0.01-0.05% of iron dichloride, the balance water. The cation surface sizing agent is prepared by starch pasting, monomer pre-emulsion and emulsion polymerization. The invention is usedfor surface sizing of paper and achieves the aim of improving physical performances of paper such as water-resistance, ring crush compression resistance, surface strength and the like.

The invention relates to a preparation method and application of an acrylate wood-plastic composite compatibilization modifier. According to the method and the application, alkene monomers of polyacrylate, vinyl acetate, maleic anhydride or the like are subjected to free radical polymerization under the action of a persulfate or azoamidine initiator by using an emulsion polymerization method so as to obtain an acrylate copolymer emulsion, an organosilane coupling agent, a titanate coupling agent, a lubricant, an anti-aging agent and the like are compounded in the emulsion so as to obtain the wood-plastic composite compatibilization modifier, and a wood-plastic composite material is prepared through uniformly mixing the emulsion with wood flour or plant stalk powder, drying a mixture after full infiltration, mixing the mixture with plastics, such as polyethylene, polypropylene, polyvinyl chloride or polystyrene, and carrying out blending and extruding or compression molding. The usage amount of the composite compatibilization modifier is small, the infiltration with the wood flour is uniform, and the matrix compatibility is high; the prepared composite material is smooth and beautiful in surface and strong in internal interface interphase toughness; and the prepared wood-plastic composite material has the advantages of low cost, high aging resistance and high impact resistance and tensile strength.

A method is provided for forming high-appearance multi-layer coating films by sequentially providing an undercoating film with a water-based intermediate coat and a topcoat while controlling the imbibing or inversion at each interface between the respective coating films. The method comprises forming an intermediate coat using a water-based intermediate coating, a metallic base coat using a water-based metallic base coating and a clear coat using a clear coating in that order on a substrate provided with an electrodeposited coat wherein the water-based intermediate coating contains an aqueous dispersion of amide group-containing acrylic resin particles having a particle diameter of 0.01 to 1.0 mum as obtained by emulsion polymerization of an amide group-containing, ethylenically unsaturated monomer with another ethylenically unsaturated monomer or monomers or monomers.