Properties of Na-Montmorillonite and Cellulose Nanocrystal Reinforced Poly(butyl acrylate-co-methyl methacrylate) Nanocomposites

Poly(butyl acrylate-co-methyl methacrylate) (BA-co-MMA) nanocomposite latexes were synthesized in the presence of sodium montmorillonite (Na-MMT) and cellulose nanocrystal (CNC) as fillers. Nanocomposite preparation with 3 wt% Na-MMT based upon the total monomer amount was conducted by semi-batch emulsion polymerization. Furthermore, direct blending of neat copolymer latex with Na-MMT was performed for comparison. CNC/BA-co-MMA nanocomposites were obtained via blending process with varying CNC content (1, 2, and 3 wt %). Good dispersion of both Na-MMT and CNC within the copolymer matrix was achieved as demonstrated by X-ray diffraction and transmission electron microscope. Particle size of the nanocomposite latexes was around 120 nm. Thermal, mechanical, and barrier properties of the copolymer showed great improvement with the addition of both Na-MMT and CNC. CNC nanocomposites displayed enhanced properties with increasing CNC level. Tensile strength of copolymer latex with 3 wt% CNC reached 262.5% of the pristine latex, while tensile strength of Na-MMT nanocomposite at the same content was 187.5% of the pristine latex. (C) 2015 Society of Plastics Engineers