Enhancement mechanism of the organic nano-montmorillonite and its effect on the properties of wood fiber/HDPE composite

摘要

Y Wood-plastic-composite (WPC) is a green environmentally friendly material, however, its relative low mechanical strength and weak thermal stability prohibited its wide application. In this study, the nanomontmorillonite (MMT) modified with silane and reinforced the HDPE/wood fiber (Populus tometosa Carr., 40-100 mesh) composite were prepared by injection molding technique for the performance enhancing of the WPC. The mechanism of the silane surface grafting, nano-OMMT intercalation, and its effects on the physical and mechanical properties of the WPC were investigated using X-ray diffraction, scanning electron microscope, thermogravimetric analysis, and mechanical tests, respectively. The results show that during the melting process, the nano-OMMT was completely stratified and dispersed in the plastic matrix, silane formed an effective chemical bond with wood fiber and established a chemical connection with the OMMT surface, which significantly improved their interfacial compatibility. With the increase of the nano-OMMT, the mechanical properties of the composite first increased and then decreased with the amount of the added nano-OMMT, while the properties of flame retardant, thermal stability, mechanics, and hydrophobicity all increased significantly with the increase of the nano-OMMT content. Specifically, the optimal value for the impact, tensile, and flexural strength properties (38.1 MPa, 21.4 KJ.m(-2), and 60.8 MPa) are achieved at the nano-OMMT amount of 10 %, the HRR and MLR of the prepared composite decreased by 17.7 % and 12.19 %, respectively. This study can contribute to the wide application of the high-performance WPC.