Chemical-mechanical effects of sawdust on elastic deflection of polymer-composites using FTIR and bending measurement

This study investigated the effect of the two types of polymer matrixes and different reinforcement materials and their percentage on the bending properties of wood-plastic composites in the elastic range of the force-deflection bending diagram, as well as FTIR spectroscopy. This work provides new insights into the early-stage deformation mechanisms of sawdust-reinforced polymer composites by isolating and quantifying the elastic-zone behavior, whereas the majority of studies concentrate on MOE and MOR from the whole diagram of three-point bending tests. The results demonstrated that mechanical properties in the elastic zone were significantly affected not only by reinforcement content and ratio but also by the polymer matrix. The mechanical properties showed a negative response to increased amounts of sawdust particles from 40 to 60%. According to the obtained results, the superior mechanical properties were achieved by using 50% sawdust in biodegradable polymer and 40% sawdust-rPET composites, respectively. Further effects of different types and ratios of reinforcements and polymer on the chemical composition of composites were studied via the ATR-FTIR method. Utilizing waste PET (rPET) and wood residual (sawdust) to produce high-performance reinforced composites may open new opportunities toward the production of added-value composites using 100% recycled and waste raw materials.