Polymer dispersion in org. medium - for prepn. of aq. solns of polymer by phase inversion

摘要

The dispersion comprises (a) a continuous org. phase which is partly miscible with water, (b) a finely divided high m.wt. polymer dissolved in or swollen by water and (c) a w/o emulsifier sol. in the org. phase and formed by polymsn. of (a) 10-50% (a) 10-50% (wt) monomers with basic N atoms (b) 90-50% monomers with =6C alkyl side chain or a mixt. of such monomers with a smaller amt. of other water insol. vinyl monomers, and opt. other surfactants, the HLB value of the emulsifying system being 6 for a pH value 4, and 8 when the pH is adjusted to 2. The dispersion is used for prepn. of aqs. soln. of any polymer g.g. polyacrylamide polyvinylpyrrolidone, PVA, polyhydroxyalkyl(meth) acrylate by adding the dispersion to an aqs. phase and acidifying to convert the emulsifier to the o/w type and cause phase inversion; the polymer then passes into soln. in the aqs. phase. The process makes use of moderate amts. of auxiliaries chemicals and reduces pollution hazard.