Effects of sintering conditions on microstructure changes of wood-ceramics impregnated with low-molecular-weight phenol-formaldehyde resin.

摘要

The microstructure of a new type of wood-ceramics made from poplar fiber impregnated with low-molecular-weight phenol-formaldehyde (PF) resin under atmospheric pressure was studied under changing sintering conditions. X-ray diffraction analysis indicated that the d002 value was reduced with increasing sintering temperature. The wood-ceramic structure also became more uniform and orderly, but still was nongraphitic carbon. Scanning electron microscopy showed that the pore structure partially retained the microstructural characteristics of wood fiber, and a graphitic phase was formed with increased sintering temperature and longer holding time. All analyses showed PF resin molecular weight had little impact on phase composition and graphitization. The apparent specific gravity of woodceramics increased as sintering temperature increased to 1200°C but decreased as temperature rose further. Specific surface area and apparent porosity were increased with higher sintering temperature, greater sintering rates, and longer holding times. In addition, specific surface area was also affected by the molecular weight of PF resin and the impregnation method, in which low-molecular-weight resin increased the specific surface area.