Abstract: Processes suitable for purifying aromatic-containing feed streams, and processes using such purified streams are described, wherein the purification processes comprise: (a) providing a process feedstream comprising an aromatic component; and (b) bringing the process feedstream into contact with a first zeolite and a second zeolite; wherein the first zeolite has a mean pore size of 0.3 to 0.5 nm, and wherein the second zeolite has a mean pore size of 0.6 to 0.8 nm.

Abstract: Processes suitable for purifying aromatic-containing feed streams, and processes using such purified streams are described, wherein the purification processes comprise: (a) providing a process feedstream comprising an aromatic component; and (b) bringing the process feedstream into contact with a first zeolite and a second zeolite; wherein the first zeolite has a mean pore size of 0.3 to 0.5 nm, and wherein the second zeolite has a mean pore size of 0.6 to 0.8 nm.

Abstract: Copolymers of monoalkyl maleates and vinyl alkyl ethers are prepared by free radical copolymerization of maleic anhydride and a vinyl alkyl ether followed by reaction with an alkanol, by a process in which the vinyl alkyl ether component is present in excess in the reaction mixture in each phase of the polymerization, the free radical copolymerization is carried out in acetone and the acetone is removed by distillation during or after ester formation at up to 70.degree. C.

Abstract: 3-Methyl-1-vinylimidazolium chlorides are prepared by quaternizing N-vinylimidazoles in aqueous solution with methyl chloride and are used for the preparation of water-soluble homo- or copolymers.

Abstract: A terpolymer of vinylpyrolidone, tert-butyl (meth)acrylate and acrylic or methacrylic acid, its use in hair treatment agents, and hair cosmetics compositions which contain these agents.

Abstract: Water-soluble terpolymers which contain, as copolymerized units,(a) from 10 to 35% by weight of an N-vinyllactam or an N-vinyl acid amide,(b) from 5 to 20% by weight of acrylic acid or of a salt of acrylic acid and(c) from 80 to 50% by weight of a C.sub.1 -C.sub.4 -alkyl vinyl ether,and have a glass transition temperature T.sub.g below 60.degree. C. can be prepared by polymerizing the monomer mixture in an inert organic solvent in the presence of a polymerization initiator and can, where appropriate, be partially or completely neutralized with a base, so as to form a salt. The products may be used as raw materials for adhesives or, in the form of an aqueous solution, as the adhesive itself.

Abstract: Readily water-soluble, slightly hygroscopic terpolymers which consist of(a) from 10 to 40% by weight of vinylpyrrolidone,(b) from 20 to 50% by weight of vinyl acetate (VAc) or vinyl propionate and(c) from 10 to 40% by weight of hydroxyethyl acrylate, hydroxypropyl acrylate or hydroxyethyl methacrylate, which terpolymers are used as auxiliaries in the cosmetics and pharmaceuticals sectors.

Abstract: A process for the preparation of high-viscosity polyvinylpyrrolidone, wherein an aqueous polyvinylpyrrolidone solution is subjected to a heat treatment in the presence of a water-insoluble peroxide and in the absence of oxygen, and thickeners containing the polyvinylpyrrolidone thus prepared.

Abstract: Polymers which due to their physiological compatibility may be used in plasma substitutes and which essentially contain vinylpyrrolidone and .alpha.,.omega.-diisocyanato-alkanecarboxylic acid esters as structural units, their preparation, and plasma substitutes containing such polymers.

Abstract: A process for the preparation of polyvinylpyrrolidone-iodine, wherein a polyvinylpyrrolidone which has been subjected to hydrogenation is reacted with iodine in a conventional manner. The novel process is particularly suitable for use with low molecular weight polyvinylpyrrolidone, having a K value of from 10 to 20.

Abstract: A process for the preparation of high-viscosity polyvinylpyrrolidone, wherein an aqueous polyvinylpyrrolidone solution is subjected to a heat treatment in the presence of a water-insoluble peroxide and in the absence of oxygen, and thickeners containing the polyvinylpyrrolidone thus prepared.

Abstract: A process for the preparation of modified poly-N-vinylpyrrolid-2-one containing two identical reactive groups, wherein polyvinylpyrrolidone is treated with complex hydrides, with or without further reaction of the modified polyvinylpyrrolidone with a reactive bifunctional compound, to give a polymer which has a molecular weight at least 2.5 times as great as that of the starting polymer.

Abstract: High molecular weight products based on N-vinylpyrrolidone, in which blocks of vinylpyrrolidone polymers or vinylpyrrolidone copolymers are linked by connecting units carrying ester, amide, urethane or urea groups, as a result of which these high molecular weight products are biodegradable and may be used as plasma substitutes, and the plasma substitutes thus obtained.

Abstract: A process for the preparation of modified poly-N-vinylpyrrolid-2-one containing two identical reactive groups, wherein polyvinylpyrrolidone is treated with complex hydrides, with or without further reaction of the modified polyvinylpyrrolidone with a reactive bifunctional compound, to give a polymer which has a molecular weight at least 2.5 times as great as that of the starting polymer.

Abstract: A process for reducing the residual monomer content of a copolymer prepared by copolymerizing vinyl esters and N-vinyl-lactams in a solvent in the presence of a free radical polymerization initiator. Following the main polymerization, from 0.05 to 0.5% by weight, based on the monomers employed, of di-tert.-butyl peroxide, di-tert.-amyl peroxide, dicumyl peroxide, 2,5-dimethyl-2,5-bis-(tert.-butylperoxy)-hexane, 2,2-bis-(tert.-butylperoxy)-butane, 1,1-bis-(tert.-butylperoxy)-3,3,5-trimethylcyclohexane, 4,4-di-(tert.-butylperoxy)-butyl valerate, or a mixture of these, is added to the reaction mixture and the after-polymerization is carried out at a higher temperature than the main polymerization.