Effect of silica dioxide on natural resistance and morphological study of wood plastic composite against of white rot fungi (Trametes Versicolor)

The objective of this study was evaluation of silica particles on natural resistance and morphological study of wood plastic composite against of white rot fungi (Trametes Versicolor). Wood flour to weight ratio of 60% with polypropylene along with 2 per hundred compound (phc) MAPP was mixed. Nano and micro silica to weight ratios 0, 1, 3 and 5 (phc) as filler were used too. The mixing process in internal mixer (HAAKE) was done and test specimens using the device injections were made. The test specimens for 8, 12 and 16 weeks in the vicinity Trametes Versicolor fungi with 25 oC and 75% humidity according to BS 838:1961 were placed. Then the mass loss, long-term water absorption and humidity coefficient diffusion on the samples were done. For ensure to the formation of hydrogen bonds between silica and wood flour form Fourier transform infrared (FTIR) spectroscopy tests and for morphological study of composite from scanning electron microscopy (SEM) was used. The result showed that with increasing period of contact samples in fungi place, the mass loss, long-term water absorption and humidity coefficient diffusion in wood plastic composite increased. But with increasing of silica, rot samples were decreased. The effect of silica nanoparticles on natural resistance of wood plastic composite was higher than from effect of silica micro particles. The effect of infrared spectroscopy showed a hydrogen bonds between wood flour and silica. The result of scanning electron microscopy showed that with increasing of contact samples with fungi, small and large cracks in composite were created but with increasing of silica this cracks were decreased.