Thermally expandable cellulose-based microspheres

A process for preparing thermally expandable microspheres, comprising mixing an aqueous phase that optionally comprises an emulsifier with an organic phase that comprises an organic solvent, a blowing agent and a carboxylate-functionalised cellulose having a Tg of at least 141° C., to form a dispersion of microspheres having a polymeric shell surrounding a hollow core, in which the polymeric shell comprises the carboxylate-functionalised cellulose, and the hollow core comprises the blowing agent and wherein the microspheres have an expanded density of from about 8.3 to about 260 g/cm3.

Thermally expandable microspheres comprising a polymeric shell surrounding a hollow core, wherein the hollow core comprises a blowing agent that is isooctane and the polymeric shell comprises a carboxylate-functionalised cellulose having a glass transition temperature (Tg) of from 141° C. to about 192° C. and selected from the group consisting of cellulose acetates, cellulose acetate propionates, cellulose acetate butyrates, and combinations thereof, and wherein the microspheres have an expanded density of from about 8.3 to about 125 g/cm3.