36 results about "N-vinylimidazole" patented technology

A grafted polyolefin containing one or more of N-vinylimidazole, 4-vinylpyridine, or other ethylenically-unsaturated nitrogen-containing or oxygen-containing graftable monomers grafted to a polyolefin copolymer is disclosed. The grafted polyolefin preferably has a weight average molecular weight of from about 20,000 to about 500,000, a polydispersity of less than about 10, and an ADT value of at least about 8. The grafted polyolefin can be defined as containing more than about 1.2% by weight of grafted monomer on a polyolefin, or as containing at least about 13 moles of graftable monomers per mole of polyolefin, or as having an asphaltene dispersancy test (ADT) value of at least about 8. Also described is a lubricating oil comprising a lubricant base oil and a grafted polyolefin as described above. Also described is a method of making a dispersant viscosity index improver. N-vinyl-imidazole or other ethylenically unsaturated nitrogen-containing and / or oxygen-containing graftable monomers and a graftable polyolefin are reacted with enough of an initiator to graft the monomer to the polyolefin. The initiator and / or graftable monomer is added to the other ingredients, maintained at the reaction temperature, over a period of time. The reaction temperature is maintained at a level high enough to give acceptable reaction times. The N-vinylimidazole and the initiator each can be added at a uniform, relatively slow rate during the reaction.

The present invention relates to the use of cationic polymers obtainable by free-radical copolymerization of a) 60 to 99 mol % of at least one 1-vinylimidazole monomer, b) 1 to 40 mol % of at least one free-radically polymerizable quaternizable monomer b1) or methacrylic acid b2) and c) 0 to 30 mol % of at least one further free-radically copolymerizable monomer different from a) and b) in hair cosmetic preparations.

The invention discloses a metallic ion-polyvinyl imidazole complex catalyst, which is a complex of a metallic ion and a polyvinyl imidazole ligand, wherein the molar ratio of imidazole groups to the metallic ion is 0.5 to 300; the metallic ion is a copper ion or manganese ion; and the polyvinyl imidazole ligand is a homopolymer of a N-vinyl imidazole monomer or copolymer of the N-vinyl imidazole monomer and another one or various water-soluble monomers and has a weight average molecular weight of 10<3> to 10<7>. The polyvinyl imidazole ligand has a large number of imidazole groups and can significantly increase the local concentration of the catalyst in a reaction medium after the complexation with the metallic ion, so the catalyst has greatly improved catalytic efficiency, achieves high PPO yield with a very small dosage when used in the preparation of PPO in a water medium, and solves the problem of the low catalytic efficiency of the prior polyphenylether catalyst prepared in the water medium.

The invention discloses a magnetic supported catalyst, which is a complex of a nano magnetic particle surface grafted polyvinyl imidazol ligand and metal ions. A molar ratio of imidazol groups to the metal ions in the complex is (0.5-300):1; and the polyvinyl imidazol ligand is homopolymer of N-polyvinyl imidazol monomers or copolymer of N-polyvinyl imidazol monomers and one or more types of water-soluble monomers. The catalyst has high catalytic efficiency, and can be separated from a reaction medium by applying a magnetic field, so that the catalyst is recycled, and solves the problem that the conventional catalyst has low catalytic efficiency of preparing polyphenyleneoxide (PPO) in a reaction medium, particularly in an aqueous medium, and is difficult to recycle. The invention also discloses a preparation method and application of the magnetic supported catalyst. The preparation method is easy to operate and control, and is suitable for industrial production.

The invention discloses a method for preparing a high-efficiency liquid-phase chromatogram filler, in particular to a method for preparing a polyvinyl imidazole type silica gel filler by an atom transfer free radical polymerization technique. The method comprises the following steps of: bromizing full porous spherical silica gel modified by an aminopropyl silanization reagent to prepare bromized silica gel; and performing atom transfer free radical polymerization on the bromized silica gel and N-vinylimidazole to generate polyN-vinylimidazole grafted silica gel. The filler has the advantages of uniform thickness of a polymerized layer, controllability, multiple action mechanism, capacity of separating many kinds of substances under the same chromatographic mode, separation under inverse phase, normal phase and ion chromatography modes, high selectivity and stability, symmetrical peak shape, high column efficiency, large column capacity, good application potential and the like.