In Situ Semibatch Emulsion Polymerization of 2-Ethyl Hexyl Acrylate/n-Butyl Acrylate/Methyl Methacrylate/Cellulose Nanocrystal Nanocomposites for Adhesive Applications

Abstract

Cellulose nanocrystals (CNCs) are safe, “green,” hydrophilic nanoparticles. CNCs are added in situ during a semibatch 2-ethyl hexyl acrylate (EHA)/n-butyl acrylate (BA)/methyl methacrylate (MMA) emulsion polymerization. As EHA is a more hydrophobic monomer, manipulation of the monomer feed composition allows for the evaluation of the effect of hydrophobicity on CNC distribution in the nanocomposite and ultimately on adhesive properties. The adhesive properties (loop tack, peel strength, and shear strength) of three different EHA/BA/MMA latex formulations are shown to simultaneously improve with increasing CNC loading. However, the hydrophobicity of the EHA leads to a nonuniform distribution of CNCs in the latex films. Comparison of the in situ polymerized nanocomposites to their blended counterparts is also made.