Fire resistance and mechanical properties of nano-wollastonite/styrene-treated poplar wood

The aim of this study was to investigate the effect of poplar wood saturation with nano-wollastonite and nano-wollastonite-styrene mixture on fire resistance and mechanical properties of polymer wood. Populus deltoids with 4% nano-wollastonite and 75% methanolic solution of styrene monomer was saturated by vacuum-pressure method. Four different wood treatments with nano-wollastonite, styrene, simultaneous nano-wollastonite and styrene (one-step) by 1:1 ratio and finally, the initial wood saturation by nano-wollastonite and then styrene (two-stage treatment) were investigated. In this study, the fire resistance and mechanical properties of the specimens were investigated. The results showed that the weight loss of wood against fire in two-stage treatment (NW+St) was 61.38% and in one-stage treatment (NW/St) was 69.68% better than control. NW/St treatment flame durability was approximately equal to NW treatment and improved by 30% compared to control. The reduction of carbonized area in two-stage (NW+St) and one-stage (NW/St) treatments was 28.53% and 29.06%, respectively, which showed a significant decrease. The results of mechanical tests showed that the NW/St treatment had the highest value due to the presence of condensing material in parallel to the NW/St treatment which showed an increase of 57.41% compared to the control sample. The modulus of elasticity and disruption of NW/St treatment increased by 26.77% and 35.71%, respectively. In addition, resistance to hardness of NW/St treatment increased by 10.07% compared to control. Overall, it can be concluded that mixing nano-wollastonite with styrene, while increasing the polymer wood fire resistance, also improved the mechanical properties of the polymer wood.