Structure and mechanical properties of new biomass-based nanocomposite: Castor oil-based polyurethane reinforced with acetylated cellulose nanocrystal

Abstract

New nanocomposites consisting of a castor oil-based polyurethane matrix filled with acetylated cellulose nanocrystals (ACNs) were developed. The ACN exhibited improved dispersion in tetrahydrofuran as a blending medium, and reduced polarity as compared with unmodified cellulose nanocrystals, resulting in a high loading level of 25wt% in the nanocomposite. As the ACN loading-level increased from 0% to 25%, the tensile strength and Young's modulus of the nanocomposites increased from 2.79MPa to 10.41MPa and from 0.98MPa to 42.61MPa, respectively. When the ACN loading-level was 10wt%, the breaking elongation of the nanocomposites reached the maximum value of more than twice that of the polyurethane. The enhanced mechanical performance was primarily attributed to the formation of a three-dimensional ACN network and strong interfacial interactions between filler and matrix. This work produced new polyurethane-based nanocomposites containing modified cellulose nanocrystal with a high biomass content. Its high performance could contribute to potential applications.