Flame retardation of fast-growing poplar wood modified with low molecular weight boracic acid compounding phenol-formaldehyde resin.
The thermal properties of low molecular weight boracic acid compounding phenol-formaldehyde resin(B-PF)were characterized with TGA and DSC, respectively. The B-PF’s effect on the fire retardancy of fast-growing poplar wood was studied. The results showed that the synthesized B-PF at the mole ratio of 1:1.9:0.3:0.3 (phenol: formaldehyde: boric acid: caustic soda) showed the characteristics of pH 7.90, solid content of 49.3%, curing temperature of 129.5°C, storage period >90 days, and light color, which can make the appearance of the B-PF treated fast-growing poplar wood being similar to the untreated. The residue weight percentage of B-PF was 73.0% at 700 , which was 25.86% higher than that of PF. When the solid content of B °C -PF was above 20%, the flame retardancy reached to nonflammable compared with the inflammable level of the untreated. The oxygen index of the B-BF treated fast-growing wood was 43.4% that is 1.28 times higher than that of the untreated.