Encapsulation of Pigments by Amphiphilic Acrylic-Polyurethane Graft Copolymers

Abstract

Amphiphilic acrylic-polyurethane graft copolymers were synthesized by grafting a blend of vinyl monomers and acid monomers to partially vinyl - endblocked polyurethanes. Carbon black and organic pigments previously dispersed in organic solvent with the aid of dispersants or in a solid hydrophobic polymer matrix, were encapsulated by these amphiphilic graft copolymers during the emulsification process which accompanied phase inversion. The emulsification process conditions and the pigment to binder ratio were investigated. Pigment encapsulation by amphiphilic acrylic - polyurethane graft copolymers containing tertiary amine functionality in the polyurethane moiety occurred without the aid of dispersants.