336 results about "Living free-radical polymerization" patented technology

The present invention is directed to the preparation of photoresist polymers via living free radical polymerization techniques. Sterically bulky ester monomers are utilized as the polymerization components. Use of chain transfer agents is included in polymerization processing conditions. Cleavage of polymer terminal end groups that include a heteroatom are described.

Disclosed are an aqueous pigment dispersion containing at least a pigment, water, a high-molecular dispersant, and an alkali. The high-molecular dispersant is a diblock polymer having a formula (1) of A-B or a triblock polymer having a formula (2) of A-B-C. The diblock or triblock polymer is a diblock or triblock polymer obtained by polymerizing addition-polymerizable monomers with a radical generator while using an organic iodide as a polymerization initiating compound and an organic phosphorus compound, organic nitrogen compound or organic oxygen compound as a catalyst. Also disclosed are a production method and use of the aqueous pigment dispersion. With the high-molecular dispersant obtained by a simple living radical polymerization process free of the problems of conventional living radical polymerization and having a precisely-controlled molecular structure, the aqueous pigment dispersion can be obtained with the pigment dispersed in it.

A radiation-sensitive resin composition comprising an acid-labile group-containing resin obtained by living radical polymerization having a specific structure which is insoluble or scarcely soluble in alkali, but becomes alkali soluble by the action of an acid, and a photoacid generator, wherein the ratio of weight average molecular weight to number average molecular weight (weight average molecular weight/number average molecular weight) of the acid-labile group-containing resin is smaller than 1.5.

Biomedical devices such as contact lenses formed from a comprising a polymerization product of a mixture comprising an ethylenically unsaturated-containing non-amphiphilic macromonomer comprising hydrophilic units or hydrophobic units derived from a living radical polymerization of one or more ethylenically unsaturated hydrophilic monomers or one or more ethylenically unsaturated hydrophobic monomers are disclosed.

The invention discloses a cellulose absorbent with a controllable structure and a preparation method of the cellulose absorbent. The preparation method comprises the following steps of grafting polymerizing cellulose by adopting cotton fibers as raw materials and iminazole ion liquid as a solvent through the polymerization of active free radicals, introducing an epoxy basic group, and aminated ringopening the cellulose grafted polymer by utilizing an amination reagent to prepare the cellulose absorbent with the controllable structure. The cellulose absorbent is faint yellow or white particles, the weight-average molecular weight is 6000 to 69000, the molecular weight distribution is 1.02 to 1.2, the content of nitrogen is 10. 16 to 23.59 percent, the molecular weight is narrow in distribution, the structure is controllable, and a good absorption effect on cation and anion pollutants can be realized.

[Problems] To provide a novel hyperbranched polymer that is optically and thermally stable, and production method thereof.

[Means for solving Problems] A hyperbranched polymer represented by Formula (1):

and having a hydrogen atom or a thiol group at a molecular terminal thereof. The hyperbranched polymer can be produced by reducing a hyperbranched polymer having a dithiocarbamate group at a molecular terminal which is produced by living radical polymerization of a dithiocarbamate compound having a vinyl group structure, or by reacting the hyperbranched polymer having a dithiocarbamate group at a molecular terminal with a thiolation converting agent.

A process for the preparation of polyvinyl chloride (PVC) with controlled molecular weight and molecular weight distribution is disclosed. The polymerization reaction can be initiated by various organic halide initiators in conjunction with a metal catalyst and an optional ligand in organic solvents or water and in the presence of an optional comonomer. The polymerization process provides PVC with a controlled molecular weight and narrow molecular weight distribution. The chlorine containing polymers compositions are useful as, among others, viscosity modifiers, impact modifiers and compatibilizers.

This invention provides a chemically coated surface for the electrophoretic separation application. The surface comprises of block copolymers prepared from addition monomers selected from a group consisting of acrylates and its derivatives, metharylates and its derivatives, styrene and its derivatives, acrylamide, methacrylamide, dimethacrylamide, N-monosubstituted acrylamide, N-monosubstituted methacrylamide, N,N-bissubstituted acrylamide, N,N-bissubstituted methacrylamide, vinyl acetate, vinyl pyrolidone, vinyl ether, acrylic acid and methacrylic acid. This invention also provides a chemical process for making the chemically coated surface for the electrophoretic separation application. The process comprises:

• • (a) contacting the support surface with a coupling agent solution, then
  • (b) contacting the support surface with a first living radical polymerizing solution, and optionally
  • (c) contacting the support surface with a second living radical polymerizing solution.

A process for producing a living radical polymer characterized in that a vinyl monomer is polymerized with use of a living radical polymerization initiator represented by the formula (1) and a compound represented by the formula (2), and the living radical polymer obtained by the process

wherein R¹ is C₁-C₈ alkyl, aryl, substituted aryl or an aromatic heterocyclic group, R² and R³ are each a hydrogen atom or C₁-C₈ alkyl, and R⁴ is aryl, substituted aryl, an aromatic heterocyclic group, acyl, oxycarbonyl or cyano

(R¹Te)₂  (2)

wherein R¹ is the same as above.

The invention relates to a preparation method of a self-supporting molecularly imprinted polymer film. The preparation method comprises the following steps of: firstly, reacting divalent metal ions with a porous alumina film to obtain a porous alumina-based layered double hydroxide; secondly, carrying out further reaction to obtain an SBC (Sulpho-Benzoyl Cyanoacetic Acid) intercalated porous alumina-based layered double hydroxide; and finally, mixing the SBC intercalated porous alumina-based layered double hydroxide with a polymerizable monomer, a polymerized cross-linking agent, a molecularly imprinted template agent and an organic solvent, dispersing by using ultrasound wave, adding a free base polymerization initiator for polymerizing, washing a product obtained by reacting and then drying to obtain the self-supporting molecularly imprinted polymer film. According to the self-supporting molecularly imprinted polymer film disclosed by the invention, the advantages of high strength, corrosion resistance, high temperature resistance and great specific area of an inorganic material as well as high load information quantity and adjustable performance of an organic polymer material can be fully exerted; the active free base polymerization is assisted in controlling; and the controllable synthesis of an ultrathin nano self-supporting structure of a molecularly imprinted material can be realized by using the controllability of the growth process of an active chain.

The invention discloses an initiation system for photo-polymerization of active free radicals of methacrylate monomers. The initiation system comprises organic halide initiators, aromatic tertiary amine reducing agents and benzaldehyde photocatalysts with substituents. Visible light (such as a household 23W energy-saving lamp) can be used as a light source for the initiation system, and polymerization of the active free radicals of the methacrylate monomers can be initiated at the room temperature. The free radicals of methyl methacrylate (MMA), polyethylene glycol methacrylate (PEGMA) and methacrylic acid benzyl ester (BnMA) monomers and the like can be polymerized under preferred matching conditions. Polymers prepared by the aid of the initiation system are macromolecular initiators, chain extension reaction is successfully carried out, and accordingly block polymers can be obtained. The initiation system has the advantages that catalysts are low in toxicity, and polymerization reaction conditions are mild; the cost of polymerization reaction is lowered to a great extent owing to the usage of organic catalysts as compared with polymerization reaction catalyzed by transition metal complexes, and after-treatment working procedures can be reduced to a great extent.

The invention discloses a structurally controllable polymethylene/poly(methyl)acrylic esters block copolymer and a preparation method thereof. The preparation method comprises the following steps: using a structurally controllable polymethylene macromolecule initiator having the number average molecular weight capable of being regulated in a certain range(500-1*10<5>g/mol) and the narrow molecular weight distribution (PDI is equal to 1.01-1.49) to initiate the atom radical transfer active free radical polymerization (ATRP) of a (methyl)acrylic esters polymerization monomer; and further preparing the polymethylene/poly(methyl)acrylic esters block copolymer (Mn is equal to *10<3>-1*10<6>g/mol, PDI is equal to1.01-1.50) which enables the molecular weight regulation for both blocks and has the narrow molecular weight distribution. The two-block copolymer can be applied to the blending study of polyolefin and the preparation of a polymer porous membrane as a compatilizer.