Determination of oxygen index levels and thermal analysis of Scots pine (Pinus sylvestris L.) impregnated with melamine formaldehyde-boron combinations

Melamine formaldehyde (MF) resin was impregnated into Scots pine (Pinus sylvestris L.) specimens with aqueous solutions of 5, 10 and 20% concentrations. Boric acid(BA) and borax(BX) was added to MF resin at the concentration levels of 0.25, 1.00 and 4.70% to each level of resin concentrations. A boric acid and BX mixture was prepared at the 5: 1 (w/w) ratio in order to obtain a nearly neutral pH of the solution and better fire resistance. Untreated and treated wood with all combinations were subjected to oxygen index test according to ASTM D 2863-91 and thermal analysis. Results were evaluated in terms of the improvement of fire retarding performances of wood by sole or combination treatments.