Study On Preparation And Properties Of Nano Enhancement Wood-plastic Composites

Wood-plastic composites (WPC) combined the advantages of both wood and plastics. They have relatively high strength and stiffness, and are biodegradable and renewable. Moreover, they can also be used widely with other materials to improve various properties.In this paper, nano-enchanced wood-plastic composites were prepared by montmorillonite (MMT) and nano-SiO2. Two different methods introduced MMT into WPC. The first method called one step, consisted of a direct addition of MMT into the composite. The second method called masterbatch, involved preparation of the masterbatch contained MMT and PE, which was then used as a material in the manufacture of WPC. Via the advanced characterization techniques, such as scanning electron microscopy (SEM), transmission electron microscopy (TEM), fourier transform infrared spectroscopic (FTIR), the properties of composites were tested and analyzed. The effects on structure and properties lead by introduction of nano-SiO2and MMT were studied.The experimental results indicated that, wood powder treated by coupling agent showed a good interfacial combination with resin matrix, decreased the roughness of fractured surface of the composite and increased the flexural strength. The interealation composite was prepared by one step and masterbatch. With the increasing of MMT content, flexural strength and impact strength of the composite first increased then decreased. The composite loaded with1%MMT exhibited the optimal mechanical properties. The dispersion of MMT in the composite prepared by masterbatch was better, so the composite prepared by masterbatch had better mechanical properties. The incorporation of nano-SiO2to the composites enhanced the flexural strength significantly, but the improvement of impact strength was not as good as MMT. The water absorption of composites increased with immersion time, but it could be restrained by incorporating nano-SiO2and MMT. Nano-SiO2absorbed the UV radiation and MMT had a screening effect. So nano-SiO2and MMT could increase the UV resistance of the composites. The addition of MMT and nano-SiO2to the composites improved thermal stability, and nano-SiO2had better effect. When the content of nano-SiO2and MMT were low, they were well dispersed in the composite. With increasing nano-SiO2and MMT, the dispersion became worse and this might have enhanced the tendency for agglomeration. To sum up, the dispersibility of nano-SiO2and MMT played a decisive role in the properties of the composite. The WPC loaded with1%nano-SiO2and1%MMT exhibited the optimal allover properties.