Comparison of mechanical reinforcement effects of cellulose nanocrystal, cellulose nanofiber, and microfibrillated cellulose in starch composites

In this work, cellulose nanocrystal (CNC), cellulose nanofiber (CNF), and microfibrillated cellulose (MFC) are used to reinforce starch to obtain high-performance starch nanocomposites by film casting. The results show that MFC is a highly efficient filler to reinforce starch compared with CNC and CNF. Largely enhanced tensile strength and modulus have been achieved (3.1 MPa, 146.7 MPa for pure starch, 10.6 MPa, 757.4 MPa for starch/MFC composite). Moreover, starch/nanocellulose nanocomposites prepared in this work exhibit excellent transparency and thermostability. Most importantly, the results of sizing performances of the nanocomposites reveal that adding of 3 wt% MFC in starch has obviously enhanced the adhesiveness of sizes to fibers. Our work may help lay a foundation for preparation of high-performance starch/MFC sizing agents, and contribute to largely expanding the industrial application of CNFs. POLYM. COMPOS., 40:E365-E372, 2019. (c) 2017 Society of Plastics Engineers