Abstract: Thermally expandable microspheres include a polymeric shell surrounding a hollow core, wherein the hollow core comprises a blowing agent, and the polymeric shell comprises an acetate-functionalised cellulose having a glass transition temperature of from about 150 to about 250° C. and a hydrogen bond donor chosen from alcohols, urea, and carboxylic acids. The microspheres are formed using a process including the step of mixing an acetate-functionalised cellulose, an organic solvent, a blowing agent and a hydrogen bond donor to form a mixture and then spraying the mixture into drying equipment to produce the thermally expandable microspheres.

Abstract: The invention relates to a process for the manufacture of thermally expandable thermoplastic microspheres. The process comprises, providing a mixture of monomeric materials suitable for polymerisation to form a thermoplastic polymer and at least one blowing agent, providing to the mixture a colloidal silica that is surface-modified with at least hydrophobic organosilane groups and forming an emulsion. A polymerisation is performed to form the thermally expandable thermoplastic microspheres. The invention further relates to thermally expandable thermoplastic micro spheres, expanded micro spheres and their use in the manufacture of products.

Abstract: The present disclosure relates to thermally expandable microspheres comprising a polymeric shell surrounding a hollow core, wherein the hollow core comprises a blowing agent, and the polymeric shell comprises a carboxylate-functionalised cellulose, wherein the thermally expandable microspheres have a temperature at which expansion starts, TStart, of from 80° C. to less than 135° C. The present disclosure further relates to a process for preparing expandable microspheres as well as to thermally expandable microspheres obtained by such process, the process comprising mixing a carboxylate-functionalised cellulose, an organic solvent, a blowing agent and, optionally, a polymer shell enhancer and then spraying the thus obtained mixture into a drying equipment to produce the thermally expandable 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.

Abstract: The invention relates to a process for the manufacture of thermally expandable thermoplastic microspheres. The process comprises, providing a mixture of monomeric materials suitable for polymerisation to form a thermoplastic polymer and at least one blowing agent, providing to the mixture a colloidal silica that is surface-modified with at least hydrophobic organosilane groups and forming an emulsion. A polymerisation is performed to form the thermally expandable thermoplastic microspheres. The invention further relates to thermally expandable thermoplastic micro spheres, expanded micro spheres and their use in the manufacture of products.

Abstract: The invention concerns an aqueous slurry comprising a thickener and thermally expandable microspheres comprising a thermoplastic polymer shell and a propellant entrapped therein, said slurry having a pH of at least about 2.5 and comprising a buffer having a pKa within about ±1 pH-unit of the actual pH. The invention further concerns a process for its preparations, use thereof for the production of paper or non-woven, and a process for the production of paper or non-woven.