Preparation and characterization of wood-plastic composite reinforced by graphitic carbon nitride

The aim of this study was to evaluate and characterize various properties of experimental composition prepared from graphitic carbon nitride (g-C3N4), wood flour (WF) and polypropylene (PP). g-C3N4 with different concentrations (1 wt.%, 3 wt.%, 5 wt.% and 10 wt.%) were used as reinforcing filler for wood plastic compositions (WPCs). Maleic anhydride grafted polypropylene (PP-g-MA) was added as a coupling agent to increase the interaction between the components. Water absorption, morphology, physical, mechanical and thermal properties of the as-prepared composites were evaluated. The results showed that the tensile modulus of the composite was increased by 142.9% with increasing of g-C3N4 contents to 5 wt.%, reaching approximately 498 MPa compared to WPC. Moreover, the flexural and tensile strengths reached their maximum values when the concentrations of g-C3N4 were 1 wt.% and 3 wt.%, respectively. When maintaining the g-C3N4 at a low concentration, it was well dispersed in the WPC with thin plate shape. However, when more g-C3N4 (3-10 wt.%) was introduced, the enhancing effect began to diminish because of the agglomeration of g-C3N4 which caused poor interfacial adhesion. The water absorption results showed a lower value with the addition of 1 wt.% g-C3N4, and the thermal tests showed that the degradation temperature shifted to higher value clearly after the addition of g-C3N4. Besides, with the addition of g-C3N4 improved the outward color compared to the control sample.