The Research On Interfacial Compatibility Of Bamboo Powder/HDPE Composites

Bamboo powder/HDPE composites is a new green material, which has combined the advantages of the plastics and bamboo. It has low production costs, excellent performance and can be recycled, greatly improving the comprehensive utilization of waste resources and has a very clear role in promoting the comprehensive management of the environment. The quality of interface compatibility directly affects the thickness of the interface between different materials, the shape of the material, the material structure and dispersion uniformity and final decision on the merits of composites. How to improve the interface between the polarity of the reinforcement and non-polar matrix compatibility is the key to the preparation excellent bamboo plastic composite materials.This paper was focused on the two aspects to improve the mechanical performance and interfacial compatibility of bamboo powder/HDPE composites, one is adding compatible agent, such as EVA and POE; the other is reducing the fiber material’s polarity——se maleic anhydride modification of the surface of the bamboo powder, discussed the preparation process of the composite material and analyzed the influence of bamboo powder mesh on the composite property. To investigate the composite bonding mechanism, samples were made to conduct mechanical properties tests, Melt flow rate tests, Thermal gravimetric(TG) analysis, Fourier infrared spectral(FTIR) analysis, Scanning electron microscopy(SEM).The results are concluded as follows:(1) Bamboo powder particle size is one of the factors impact of bamboo and plastic composites. In40mesh to200mesh bamboo powder particle size range, with bamboo powder mesh increases the tensile strength and notched impact strength was a downward trend; composite melt flow rate showed an upward trend after the first decreases. Composite cross-section SEM images show that the composite cross-section is not flat, part of the fibers are pumped to pull out, many voids exist between the two phases, exist the bamboo powder gathered phenomenon, combination between the fiber and the matrix are poor. The Cross-section pore of40mesh bamboo powder is deeper than200mesh bamboo powder. Bamboo powder deeper interface diffusion and mechanical interlocking formed at the interface helps to improve the mechanical properties of composites. Compared with100mesh bamboo powder,200mesh bamboo powder has smaller particle size, more uniform, better dispersion in the matrix,and therefore have a better performance.(2) EVA molecular chains has the polar monomers vinyl acetate, can form chemical bonds with the hydroxyl in the bamboo powder, reduce the bamboo powder polarity, thus improving the compatibility between the bamboo powder and HDPE. Join the EVA can greatly improve the notched impact strength of composites, and has an upward trend in the composite melt flow rate within a certain range of add, but add too much EVA will affect the tensile strength of the composites. Add9%of the EVA Capacity bamboo powder/HDPE composites SEM analysis showed that the surface of the bamboo powder was coated by the matrix resin, reducing the polarity of the bamboo powder, improved bamboo powder and resin matrix interface compatibility.(3) POE molecules octene soft chain coil structure and crystallization of the ethylene chain as physical crosslinking points, making it has both excellent toughness, and have good workability. POE adding can greatly improve the elongation at break and notched impact strength of composites, the composite melt flow rate on an upward trend within a certain range of add, while the tensile strength of composite materials with the POE content is increase downward trend. Joining the15POE composite cross-section SEM shows that many brushed phenomenon between the resin matrix, and the distribution of many "tough nest", the mobility of the resin matrix improved, making bamboo powder in a resin matrix dispersion of relatively uniform. These microscopic phenomena further proof that the POE joined improved the performance of composite materials and the compatibility between the bamboo powder and resin matrix.(4) Use maleic anhydride (MAH) for interface modifier, choose polyethylene wax for the bamboo powder surface modification is an effective treatment method to improve the performance of the composite interface.Through orthogonal test choose the best bamboo powder processing method, eventually obtained the tensile strength of the composites is24.52MPa, the notched Izod impact strength is4.94KJ/m, the melt flow rate is3.85g/10min.Compared with untreated bamboo powder/HDPE composite, the samples performance were increased by43%,11%,66.7%.By Fourier transform infrared spectroscopy confirmed that the Polyethylene wax grafted with maleic anhydride to the bamboo powder, the treatment agent and bamboo powder in a chemical reaction. MAH processing bamboo powder/HDPE composite TGA curves showed that the maleic anhydride processing contributee to the improvement of the thermal stability of the composite. Scanning electron microscopy showed that after processing by maleic anhydride, the surface of the bamboo powder coated by polyethylene wax makes the bamboo powder more easily dispersed in the matrix, agglomeration is greatly reduced, the interfacial bonding between the bamboo powder and matrix is closer than before.