Mechanical & Interfacial Properties of Bamboo Lamella-PP Composites – Effect of Lamella Treatment

This study aims at measuring the interfacial properties of natural fibers in polypropylene composites by the mean of direct methods of characterization. Bamboo lamellae (BL) and polypropylene (PP) were used to produce laminated composites with continuous and homogenous interfaces. This research also focuses on the effect of maleic anhydride-grafted PP (MAPP) on the improvement of the PP/BL composites interfacial properties, which were measured by the means of the double cantilever beam (DCB), end-notched flexure (ENF) and short beam shear (SBS) methods. Flexural properties of the different composites were also determined using the three-point bending and single cantilever modes by dynamic mechanical analysis (DMA). The retention rates (Rr) of mechanical and interfacial properties were calculated on samples aged in hot water. Results reveal that MAPP induced a significant increase in flexural properties. This is undeniably related to an enhancement of affinity between PP and BL that was confirmed by DCB, ENF and SBS tests results. It was also highlighted that MAPP tends to limit degradation of the composite interfacial properties with,for instance, a critical fracture toughness (mode I) Rr of 97 % for MAPP coated composites against 56 % for the untreated composites.