Effects of bamboo cellulose nanowhisker content on the morphology, crystallization, mechanical, and thermal properties of PLA matrix biocomposites

To improve the mechanical and thermal properties of poly (lactic acid) (PLA) composites, bamboo cellulose nanowhiskers (BCNW) were extracted and introduced into PLA composites as fillers. PLA/BCNW biofilms were fabricated by solution casting with different BCNW contents (0, 0.5, 1.0, 1.5, 2.0, 2.5, 3.0, 3.5, and 4.0 wt%). The characteristics of the biofilms were investigated by scanning electron microscopy (SEM), mechanical measurements, synchrotron radiation wide-angle X-ray scattering (WAXS) and differential scanning calorimetry (DSC). The results showed that the maximum tensile modulus and elongation at break of 427.72 +/- 19.32 MPa and 22.27 +/- 3.50% were reached at 2.5 wt% and 1.0 wt% loadings, respectively. Both homogeneity and stereocomplexed crystallites were observed, and heterogeneous nucleation effect was confirmed. With the addition of BCNW, the crystallite size of PLA/BCNW composites increased remarkably, and the largest crystallinity was 30.7 +/- 0.9% with 2.5 wt% BCNW. These results provided data support for enlarging the application of PLA. (C) 2017 Elsevier Ltd. All rights reserved.