CHEMICALLY JOINED, PHASE SEPARATED GRAFT COPOLYMERS HAVING DIBLOCK POLYMERIC SIDECHAINS

摘要

1496931 Hydrophilic copolymers CPC INTERNATIONAL Inc 10 Jan 1975 [11 Jan 1974] 1196/75 Heading C3P Hydrophilic, water - insoluble copolymers having a structure analogous to graft polymers in the form of a hydrogel are formed by copolymerizing a hydrophobic macromolecular monomer and a hydrophilic comonomer or a comonomer giving a polymer which can be made hydrophilic wherein (1) the macromolecular monomer has a molecular weight of at least 2,000 and a Mw/Mn ratio not above 1À1 and has only one terminal polymerizable group per molecule and (2) the comonomer is chosen so that by reason of the reactivity ratios the hydrophobic monomer units are separated by at least 20 comonomer units in the polymer, if necessary converting the polymer to a hydrophilic form, and forming a hydrogel containing 10-95% by wt. of an aqueous liquid. The macromolecular monomers are anionically polymerized dienes and/or vinyl aromatics terminated with a single polymerizable, usually ethylenically unsaturated group, as described in Specifications 1,392,612, 1,432,782 and 1,432,783. In examples they are polymerized with acrylic acid, vinyl acetate which is saponified to vinyl alcohol after polymerization, ethyl acrylate hydrolysed to acrylic acid, hydroxyethyl methacrylate, N,N- dimethyl acrylamide, optionally with butyl acrylate, or maleic half ester of methoxy polyethylene oxide.