Preparation of low molecular mass homopolymers of N-vinylpyrrolidone
AssigneeBASF SE
InventorsStephan Kothrade, Rainer Blankenburg, Iris Peters, Axel Sanner
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Abstract
A process for preparing highly concentrated aqueous solutions of low molecular mass homopolymers of N-vinylpyrrolidone by free-radical solution polymerization in an aqueous medium with H2O2 as initiator comprises carrying out the polymerization in the presence of from 0.1 to 30% by weight, based on N-vinylpyrrolidone, of a polymerization regulator which is selected from the group consisting of C1-C6-alkanols, hydroxylamine salts and water-soluble compounds containing sulfur in bonded form.
Claims9
A process for preparing an aqueous solution of low molecular mass homopolymers of N-vinylpyrrolidone having a weight average molecular mass of from 5000 to 60,000, which has a solids content of more than 45% by weight, the process being a free-radical solution polymerization in an aqueous medium with H2O2 as initiator, which comprises carrying out the polymerization in the presence of from 0.1 to 30% by weight, based on N-vinylpyrrolidone, of a polymerization regulator which is selected from the group consisting of C1-C4-alkanols.
A process for preparing highly concentrated aqueous solutions of low molecular mass homopolymers of N-vinylpyrrolidone, which has a solids content of more than 45% by weight, the process being a free-radical solution polymerization in an aqueous medium with H2O2 as initiator, which comprises carrying out the polymerization in the presence of from 0.1 to 30% by weight, based on N-vinylpyrrolidone, of a polymerization regulator which is selected from the group consisting of ethanol, n-propanol or isopropanol.
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