Surface modification of cellulose nanofibrils for poly(lactic acid) composite application

3-Methacryloxypropyltrimethoxysilane (MEMO) was used to modify the surface of cellulose nanofibrils (CNF) to improve the interfacial adhesion between the hydrophilic CNF and the hydrophobic poly(lactic acid) (PLA). MEMO modified CNF (M-CNF) were characterized by means of Fourier transform infrared spectroscopy (FTIR), thermo gravimetric analysis (TGA), and atomic force microscope (AFM). Testing thin films with good transparency were obtained by casting the DMAC solutions of the composites onto glass plates and evaporating the solvent at 80 degrees C. PLA/M-CNF composites were tested by tensile testing, scanning electron microscope (SEM), and AFM. The effect of MEMO and CNF on performance of PLA was investigated. The FTIR analysis successfully showed that coupling reaction has been successfully occurred and the hydroxyl groups of MEMO are strongly hydrogen bonded to that of CNF. The thermal stability of M-CNF was little decreased. The M-CNF kept their morphological integrity. The highest tensile strength of composites was obtained for PLA with 1.0% v/v MEMO and 1.0 wt % CNF. M-CNF disperse well and cross with each other in the PLA matrix. (C) 2012 Wiley Periodicals, Inc. J Appl Polym Sci, 2012