Microemulsion Polymerization of Microlatex in Sublimation Ink for Cotton Fabric Ink Jet Printing

A novel microlatex of styrene/2-ethylhexylacrylate (2-EHA)/2-hydroxyethyl methacrylate (2-HEMA)/N-(isobutoxy methyl) acrylamide (IBMA) copolymer was synthesized and mixed in sublimation inks to be inkjet printed on the cotton fabric to provide soft hand feel and good color fastness after heat-press. In the optimized microemulsion composition with highest monomer mixture amount, polymerizable maleate surfactants with moderate EO value attained smaller microemulsion droplet size in mono distribution and lower dosage than conventional POE surfactants in combination with anionic surfactants. With adopted semicontinuous process in microemulsion copolymerization at 65 degrees C, the polymerizable surfactants stabilized the growth of microlatex particle size within 70 nm in 240 min and attained 100% of monomer conversion rate with two initiator systems, 2-2-azobis(2-methlypropionamidine dihydrochloride (AAPH) and tert-butylhydroperoxide (TBHP)/sodium formaldehyde sulfoxylate (SFS). The microlatex particle size of two surfactant systems increased with higher conversion rate and reaction temperature, which synchronized with initiator concentration. High polymer solid content was contributed mainly by IBMA monomer ratio requiring higher amounts of anionic surfactants and 2-HEMA as a cosurfactant in particle stabilization. Although the optimum ink containing high IBMA microemulsion exhibited small variation in viscosity, pH value and surface tension, disperse dyes in four colors had different interaction with the microlatex to demonstrate distinct printing durability and color performance. The resulted cotton fabric attained high K/S value for color strength, great AATCC grade for color fastness, and nearly zero color difference for negative dye particle diffusion or migration. (C) 2011 Wiley Periodicals, Inc. J Appl Polym Sci 122: 1872-1881, 2011