Improvement in fire retardancy with double-step chemical modification on Pinus radiata D. Don using dimethyl methylphosphonate with propylene oxide and maleic anhydride

ABSTRACT Wood is prone to fire attack making its application restricted as building material. The current study aims to evaluate the effect of double step chemical modification on Pinus radiata using Dimethyl Methyl phosphonate with Propylene oxide and Maleic anhydride. Wood samples were modified by single step using Propylene oxide (PO) or Maleic anhydride (MA) and the double-step modification comprised firstly of pressure treatment with Dimethyl Methyl phosphonate (DMMP) followed by chemical modification using Propylene oxide (PD) or Maleic anhydride (MD). Thermal property was studied using Thermo Gravimetric Analysis (TGA) and Derivative Thermogravimetric (DTG). The chemical modification resulted in better thermal stability of wood than control wood. Among treatments PD showed best fire retardancy property with maximum weight loss at 367°C with 18.2% residual mass. The preliminary study indicates that double step modification improved the thermal property increasing the temperature for maximum weight loss and residual mass comprising of char.