Recycled Cardboard Containers as a Low Energy Source for Cellulose Nanofibrils and Their Use in Poly(<scp>l</scp>-lactide) Nanocomposites
Katie Copenhaver, Kai Li, Meghan E. Lamm, Colleen C. Walker, Donna Johnson, Yousoo Han, Lu Wang, Xianhui Zhao, Yunqiao Pu, Holly Hinton, Halil Tekinalp, Samarthya Bhagia, Arthur J. Ragauskas, Douglas J. Gardner, Soydan Ozcan
Abstract
Cellulose nanomaterials have attracted a great deal of interest as sustainable alternatives to nonrenewable or fossil fuel-derived materials, particularly in composite applications. Cellulose nanofibrils (CNF) are most often derived from wood sources through energy-intensive and costly mechanical fibrillation processes. In this study, recycled cardboard, referred to as old corrugated cardboard (OCC), was investigated as an alternate CNF source. OCC is a recycled material that can be obtained at one-tenth the cost of the commonly used bleached softwood Kraft pulp and can be refined to similar levels with nearly one-half of the energy consumption. Additionally, the distinct composition and morphology of OCC-derived CNF provides a more favorable fiber–matrix interface and better reinforcement capabilities of the cellulose nanofibrils in polymer matrices, displaying an over 70% increase in tensile modulus at a loading of 40 wt % with no decrease in tensile strength. When paired with biobased poly(l-lactide) (PLLA), OCC-derived CNF is proven to be an attractive low-cost and low-energy reinforcing agent for sustainable, high performance nanocomposites.