Effects of surface modification on the physical, mechanical, and thermal properties of bamboo-polypropylene composites

To fabricate homogeneous bamboo fiber reinforced thermoplastic composites, polypropylene (PP) fiber and 3-aminpropyltriethoxysilane (APTES) modified bamboo fibers were first formed into mats by non-woven air paving technology, and then the composites were created by hot-pressing the mats. The modification of BFs was characterized by XPS and FTIR analyses, and the results confirmed that APTES had been grafted onto the surfaces of BFs. The effects of concentrations of APTES on the mechanical, physical, morphological, and thermal properties of the bamboo-polypropylene composites were examined by tests of bending strength, scanning electron microscopy (SEM), differential scanning calorimetry (DSC), and water absorption. The analysis of physical and mechanical properties revealed improved mechanical properties and water resistance (3 wt% of APTES). SEM images were used to assess the influence of modification treatment on the properties of the composites. The results confirmed that the modification of APTES improved the interfacial adhesion between BFs and PP matrix. DSC results indicated the melting point of composites decreased with an increase in concentration of APTES up to 3 wt%, while the melting point of composites increased when the concentration of APTES was higher than 3 wt%.