Cross-Linked Primer Strategy for Pigment Encapsulation. 1. Encapsulation of Calcium Carbonate by Emulsion Polymerization

Abstract

We demonstrate a versatile method to encapsulate calcium carbonate particles with a shell of polymer by means of a conventional free radical emulsion polymerization process. Our strategy relies on the encapsulation of the pigment particles with a thin primer layer of cross-linked poly(acrylate). Starved-fed addition and emulsion polymerization of di(ethylene glycol) diacrylate and methacrylic acid allow the uniform decoration of the pigment particles with the polymer primer shell. We demonstrate efficient encapsulation of calcium carbonate, from which we produce hollow particles upon calcium carbonate etching. The thickness of the polymer shell can easily be controlled, which we demonstrate with sequential seeded polymerization of methyl methacrylate under starved-fed conditions.