Surfactant-free hybrid latexes from enzymatically hydrolyzed starch and poly(butyl acrylate-methyl methacrylate) for paper coating.

The use of starch as renewable resource to produce eco-friendly hybrid latex has received an increasing attention in industrial application. In this work, enzymatically hydrolyzed starch-graft-poly( n -butyl acrylate- co -methyl methacrylate) (ES-g-P(BA-MMA)) latexes were synthesized by seeded surfactant-free emulsion polymerization. A complex initiation system was used to enhance the grafting efficiency. The mechanisms of initiation and graft copolymerization were discussed. The ES-g-P(BA-MMA) latexes were characterized by Fourier transform infrared spectroscopy, dynamic light scattering, transmission electronic microscopy (TEM), and differential scanning calorimetry. The effect of reaction condition on graft copolymerization was investigated. The evolution of particle morphology was revealed by the TEM. The ES-g-P(BA-MMA) latexes were used as binders for paper coating. The strength-related properties of coated paper were evaluated. The results showed that the folding resistance and picking resistance were improved. All the other properties were at least equally good as in the reference sample. The crosslinked ES-g-P(BA-MMA) latex was more effective in improving properties. The folding resistance and wet tensile strength index were enhanced significantly by 29.5% and 36.6%, respectively. This study provides an alternative choice for paper coating to develop coated paper with better properties. [ABSTRACT FROM AUTHOR]