Preparation And Characterization Of Tobacco Stems Based Woodceramics

A severe pollution on our environment was caused by mankind as the society advancement and economic development. The problem of disposaling and utilizing the waste materials based on effective consumption of natural resources has become the hindrance of the society advancement and economic development. Therefore, more and more attention was paid on ecomaterials with minimal impact on environment. Woodceramics is a new kind of ecomaterials being developed in recent years. As a porous carbon material, it is made from wood or woody materials impregnated with thermosetting resin such as phenolic resin in a vacuum furnace. Woodceramics was reported to have many excellent performances such as good electrical, friction and wear resistance, corrosion resistance, high strength, lightweight and porousness, electromagnetic shielding ability, and therefore, it has potential application in many industries. However, the problems of costly raw material and anisotropy of structure about woodceramics haven't solved until now, they obstructed the development of woodceamics and extending application fields of woodceramics.So, this paper reviews the fabrication methods of woodceramics based on different raw materials and different technology. And then a new technology has been developed to prepare woodceramics using the waste materials of tobacco stems and phenolic resin as raw materials. The results show that the waste materials of tobacco stems can be used to fabricate woodceramics with this technology. After the raw materials was studied by the thermogravimetry analysis, the effects of carbonization temperature, the mass fraction of phenolic resin and holding time on properties and structure of the woodceramics were investigated. And the structure of woodceramics was characterized by the techniques of X-ray diffraction (XRD), the laser Raman spectroscopy, X-ray photoelectron spectroscopy (XPS) and scanning electron microscopy (SEM).Thermogravimetry analysis results on tobacco stems, phenolic resin, and carbon derived from tobacco stems/phenolic resin composites were reported. The temperature of carbonization tobacco stems was determined by studying the pyrolytic behaviors of samples at four different heating rates of 1K/min, 5K/min, 10K/minand 20K/min. The thermogravimetric and derivative differential thermo -gravimetric were carried out to determine the rate of samples evolution, the effect of heating rates on the thermal degradation characteristics and to determine the global mass loss ratios of thermal degradation. The thermal degradation was found to occur in several distinct phases: each phase giving sample evolution in an independent parallel lump. The pyrogenation of carbon derived from tobacco stems/phenolic resin composites are different to the tobacco stems and phenolic resin, and the decomposition of every component in the composites is intricate.In the present study, the woodceramics which was made from carbon derived from tobacco stems/phenolic resin composites were developed at different conditions. And the effects of the carbonization temperature, the mass fraction of phenolic resin, and the holding time at the mass loss ratio, volume shrinkage ratio, apparent density, open porosity, volume electrical resistivity and bending strength of the woodceramics were investigated. The results show that with the increase of carbonization temperature, the mass loss ratio, volume shrinkage ratio, apparent density and bending strength were increasing, but open porosity and volume electrical resistivity were reducing. And with the increase of the mass fraction of phenolic resin, the apparent density and bending strength were increasing, others were reducing. And with the prolonging of the holding time, they were increased aside from apparent density and volume electrical resistivity.A series of woodceramics derived from carbonized tobacco stems and phenolic resin are studied by the X-ray diffraction technique. It can be found that woodceramics is a kind non-graphitic carbon materials. With increase of carbonization temperature, increase of the mass fraction of phenolic resin and the prolonging of the holding time, the interlayer spacing of graphene sheets in microcrystal of woodceramics,