Preparation of nano-encapsulated polyethylene wax particles for color toner by in situ emulsion polymerization

Polystyrene-acrylate resin coated polyethylene (PE) wax composite particles used for color toner were prepared by in situ emulsion polymerization. The laser particle analyzer and transmission electron microscope (TEM) were applied to show the size and morphology of composite particles, and thermogravimetric analysis (TGA) was used to characterize the thermal properties of the nanoparticles. With the increase of emulsifier triton x-100 (TX-100), the size of composite particles decreased at first and then increased and the shell thickness increased gradually. When the mass ratio of TX-100 to monomers was 1:10, the core-shell structure of the latex particles was the clearest. The homopolymer of styrene (St) and copolymer of styrene-butyl acrylate (St-BA) showed few differences on the size of the composite particles, but a significant difference on the thermal performance. The FTIR spectra and dissolution experiments of PE wax/P(St-BA) composite particles provided supporting evidence for encapsulation. With the increasing percentage of polyethylene wax, the particles size got larger and emulsion shelf stability became worse. The size and the shelf stability got optimized when the reaction temperature was 80 degrees C. The average size of the particles initiated by 2,2-azobisisobutyronitrile (AIBN) was smaller and the size distribution was narrower than those of initiated by potassium persulfate (KPS). (C) 2016 Wiley Periodicals, Inc.