Pyrolysis of wood-based polymer compounds

Due to increasing costs of synthetic polymers or plastics, which are directly correlated with the oil and gas prices, natural polymers with similar properties are becoming more and more interesting. One such product is a commercially available wood-based compound Arboform® composed largely of lignin and cellulose. From these two materials, lignin is largely a byproduct of the paper industry, and normally used as a fuel. This material has the property of being able to be injection moulded into complex structures. Additions of carbon fibres to this mixture increase the form stability and the electrical conductivity. The pyrolysis of this material can form conducting materials. Thus, this material can also be used as a low-cost alternative to complex, conducting and non-oxidising components. A chemical and structural analysis with surface sensitive methods (XPS, EELS, and SEM) was performed to understand the pre- and post-pyrolysed material. Results show that pyrolysis increases the graphitic content and conductivity of the wood-based polymer compound. Furthermore, an anisotropic conductivity dependent on carbon fibre alignment in the compound was also observed.