Procedure controlled radical polymerization of acrylic acid and salts thereof, polymers obtained polydispersity weak, and its applications.

摘要

Method for the homopolymerisation of acrylic acid and its salts or copolymerization of acrylic acid with one or more water-soluble monomers, in solution, for obtaining non-crosslinked polymer, characterized by using as the agent (or agents) transfer products selected from those defined by the general formula: X ------ ------ R C (S) ------ S ------ R 'in which: X = O or S, R It represents a group that allows for the function R - X by a covalent bond type C - X. R '' represents a group so that the link R '' - S is a link type C - S, and the reaction parameters and the choice of transfer agents are adapted so that possible get simultaneously the criteria indicated below a) very weak molar masses IP Mn greater than 1000, i.e. one IPexp 2 without physical or physico-chemical separation and determined according to the method known as IP, b) absence of gel polymerization even at high conversion rates well, that is above 90%. c) very high conversion rate ( 90%) in a reasonable reaction time for industry, is after 4 hours at 100 ° C mean, preferably after 2 hours at 90 ° C and atmospheric pressure. d) using a quantity of agent (s) ranging from 0.001% transfer 20% (molar) and 0.01% to 50% (mass), more particularly between 0.01% and 10 % and even more particularly between 0.01% and 5%.