Fabrication and the barrier characterization of the cellulose nanofibers/organic montmorillonite/poly lactic acid nanocomposites

The hydrophobic modification of cellulose nanofibers (CNF) was carried out via free radical polymerization using methyl methacrylate (MMA) as the monomer to improve the compatibility between CNF and poly lactic acid (PLA). Followed by the preparation of the novel nanocomposites in combination of the organic montmorillonite and the substrate. The resulting nanocomposites were then coated on paper surface using a cast-coating process in an attempt to improve the barrier properties towards water vapor and oxygen. In addition, the composite films are prepared via a solution casting method. The water vapor transmission rate (WVTR), water vapor permeability (WVP), oxygen transmission rate (OTR), and tensile strength of the as-prepared films were systematically measured. The corresponding results demonstrated that the WVTR, WVP and OTR decreased with the addition of a certain content of MCNF in coatings. 0.2 wt% MCNF is the optimum content, showing the best gas resistance and tensile performance. The lowest value of WVTR and WVP are 10.30 g/(m(2)MIDLINE HORIZONTAL ELLIPSIS24 h) and 3306.58 gMIDLINE HORIZONTAL ELLIPSIS mu m/(m(2)MIDLINE HORIZONTAL ELLIPSIS24 h) for films with 0.2 wt% MCNF added, which is 88.23% and 26.05% lower than that of PLA composite film without NFC.