A method of preparing a polymer dispersion comprising (i) contacting an aqueous dispersion of de-ionized acidic colloidal silica particles with a first mixture of monomers to form a combination; (ii) polymerizing such combination at an initial pH of from 2 to 5 to at least 90% in completion; and (iii) adding a second mixture of monomers at a rate substantially equal to the rate of consumption of such second mixture of monomers to continue and complete the polymerization. The present invention further provides a polymer dispersion made from the above method.

Compositions and methods for additive manufacturing applications are described herein which, in some embodiments, impart flame resistant and/or flame retardant properties to articles printed or formed from the compositions and methods. In some embodiments, a composition described herein comprises an aluminum-containing species. In some cases, the aluminum-containing species comprises Al(OH).sub.3. In some instances, the aluminum-containing species comprises a species of Formula I or Formula II described herein.

Compositions and methods for additive manufacturing applications are described herein which, in some embodiments, impart flame resistant and/or flame retardant properties to articles printed or formed from the compositions and methods. In some embodiments, a composition described herein comprises an aluminum-containing species. In some cases, the aluminum-containing species comprises Al(OH).sub.3. In some instances, the aluminum-containing species comprises a species of Formula I or Formula II described herein.