Synthesis of poly(isobutyl acrylate/n-butyl acrylate/methyl methacrylate)/CNC nanocomposites for adhesive applications via in situ semi-batch emulsion polymerization

Pressure sensitive adhesive (PSA) films were prepared from in situ semi-batch emulsion polymerizations using isobutyl acrylate, n-butyl acrylate, and methyl methacrylate in the presence of cellulose nanocrystals (CNCs). The CNCs at loadings of up to 1 wt% with respect to monomer resulted in significant and simultaneous improvement in tack, peel strength and shear strength for the PSA films. While most latex properties were unchanged, the CNCs also led to increased latex viscosity. A range of compositions were used to test the limits of the application. Microscopy was used to demonstrate that the CNCs were dispersed throughout the latex but outside of the polymer particles. Comparison to latex/CNC blends showed that the in situ technique provided higher shear strength PSA films. POLYM. COMPOS., 40:1365-1377, 2019. (c) 2018 Society of Plastics Engineers