Waterbone Casein/acrylic Nanoparticles

PICCHIO, MATÍAS L.; MINARI, ROQUE J.; VEGA, JORGE R.; BARANDIARAN, MARÍA J.; GUGLIOTTA, LUIS M.

Pisa

Congreso; European Polymer Congress 2013; 2013

European polymer federation

Casein had long been used as principal binder in leather finishing and paper coatings for its good stained acceptance, finishing glazed aspect and good substrate penetrability [1]. However, casein films present susceptibility to microbial attack, and poor mechanical properties. For this reason, the casein grafting aims to modify the properties of such protein on the basis of a synergetic combination with other polymeric materials. In this work the emulsion polymerization of acrylic monomers (butyl acrylate/methyl methacrylate, BuA/MMA) in the presence of casein was investigated with the objective of producing waterborne casein/acrylic nanoparticles with controlled microstructure and nanomorphology able to be applied as coatings and/or adhesives partially biodegradable and with improved properties. The redox initiation system involving tert-butyl hydroperoxide (TBHP) and amine casein [2] was adopted in this work. Polymerizations of BuA/MMA in the presence of variable amounts of casein (from 3 to 50 % weight based on monomer) were carried out in batch at 80ºC. Polymerization kinetics, molecular microestructure of the casein-acrylic nanoparticles, and film properties from the synthesized lattices are discussed. Compatibilized waterborne acrylic/casein nanocomposites with improved film properties (mechanical and adhesive, transparency and flexibility) were successfully synthesized.