Effects of fiber-surface modification on the properties of bamboo flour/polypropylene composites and their interfacial compatibility

Abstract This work aimed to study the effects of different surface treatments on the morphologies and thermo-mechanical properties of the bamboo flour/polypropylene (BF/PP) composites, which were prepared by melt blending with 15 wt% of filler load. The BF was first pretreated with 10 wt% sodium hydroxide (NaOH) solutions for 4 h, after which the pre-treated BF was modified by stearic acid and silane. The chemical structure of the treated BF fibers was characterized through Fourier transform infrared spectroscopy (FTIR), and the results showed that alkali treatment efficiently removed hemicellulose, lignin, and pectin. Moreover, stearic acid and silane were successfully introduced to the BF surface through chemical bonding. The changes in heat stability of BF investigated by thermogravimetric analysis (TGA) revealed that the presence of treatment contributes to a better thermal stability for BF fibers. In addition, the scanning electron microscopy (SEM) observation of BF/PP composites displayed not only better dispersion of treated-BF in the polypropylene (PP) matrix, but also improved fiber-matrix interfacial compatibility, especially when silane treatment was used. Accordingly, the mechanical properties improved significantly in the presence of treated-BF.