“Nanosized latexes for textile printing applications obtained by miniemulsion polymerization”

We report the synthesis and design of aqueous monodisperse copolymer latexes by miniemulsion polymerization and their application as binders in pigment printing and ink-jet printing of cotton fabrics. For that purpose, miniemulsion radical polymerization was carried out with a high content of the soft butyl acrylate (BA) and a low content of the hard methyl methacrylate (MMA) in the presence of hexadecane as osmotic costabilizer. The addition of small amounts of functional monomers such as methacrylic acid MAA and N-methylol acrylamide NMA to some miniemulsion recipes allowed to impart cross-linking sites and functionality to the copolymer chains. Dynamic light scattering (DLS), small angle neutron scattering (SANS), and transmission electron microscopy (TEM) showed that the particle size diameter and size distributions could be controlled in the range of 50 to 400 nm by the amount of SDS surfactant, while the presence of a costabilizer such as hexadecane determines the particle size and, to a lesser extent, the polydispersity of the obtained miniemulsion latex dispersions. The glass transition temperature of the different miniemulsion latexes ranged between −14 and −33 °C, depending on the monomer composition. Selected samples of these nanolatexes were then employed in textile printing. The miniemulsion binders with their uniform shape and smaller size have technological advantages over conventional processes for the pigment and ink-jet printing and yielded better printing properties in terms of softness, fastness, and color strength of the printed fabric. Accordingly, by optimized use of the miniemulsion method, one is not only able to control the particle size but also to improve the properties of these latexes for textile applications.