Polymerization Processes of Emulsifier-free Pickering Emulsion Stabilized by Nanocrystalline Cellulose

Abstract

Styrene was used as the monomer, ammonium persulfate as the initiator, and the nano-cellulose (NCC) obtained by hydrolyzing microcrystalline cellulose with sulfuric acid was used as the stabilizer for solid particles. Then the Pickering emulsion, which can be stable for a certain time, was prepared by emulsifier-free emulsion polymerization by ultrasonic homogenization. The solid content and conversion and emulsion rates were calculated. The material was examined by infrared spectroscopy and scanning electron microscopy. Its stability and other characteristics were described. The average NCC particle size was 187.2 nm, and the particle size distribution coefficient of PDI was 0.394. The styrene Pickering emulsion was stable for 20 d, and the emulsion rate was stable at approximately 0.7. The conversion rate of the polymerization emulsion was approximately 80%. When the content of NCC was approximately 3% to 4%, the maximum degree of sizing was approximately 42 s, and the water resistance was better than Pickering emulsion with other NCC additions.