Research On Flame-retardant Treated Pinus Sylvestris Wood Properties

Wood materials, as a kind of traditional and environmentally friendly materials, has been applied to many areas. However, the use of wood materials are limited in many environments, due to its flammability and huge losses to the people of fire caused by its flammability. It is significant to make research of Pinus sylvestris about flame retardant treatment process and flame retardancy that Pinus sylvestris is one kind of close texture and widely used wood.In the paper, the influence of the experimental conditions of solution concentration, the vacuum, the vacuum time, the pressure, the time on flame retardant treated Pinus sylvestris are researched, the Pinus sylvestris wood as the research object, preparing flame retardant FRW solution and using vacuum pressure impregnation method. And then, the best flame retardant treatment process is developed, the synergistic effect of flame retardant FRW/ammonium polyphosphate APP and guanylurea phosphate GUP/disodium octaborate tetrahydrate DOT with treatment on Pinus sylvestris were also studied by the means of limited oxgen index, vertical flame teat, thermogravimetric analysis, cone calorimetry and scanning electron microscope.It is concluded that, the best flame retardant concentration of treated Pinus sylvestris is 10%, the vacuum is 0.1 MPa, the vacuum time is 10-20min, the pressure is 0.6MPa, the pressure time is 20-30min. It is found out that the most effective flame retardant loading is 11%-12% through heat release rate HRR, total heat release THR and total smoke release TSP.The flame retardant system of FRW/APP at the mass proportion 4/1 has a good synergistic effect to Pinus sylvestris with the experiment results LOI value of 55.6%, UL94 V-0 rating. By TGA and CONE calorimeter test show that the heat release rate HRR, total heat release THR, effective heat of combustion EHC, the concentration of CO and CO2 decreased, and slightly increased char rate. the char residue of FRW/APP retardant treatment Pinus sylvestris show a closely overall network structure without flame retardant granules attached on the surface by SEM,.It is concluded that, the flame retardant system of GUP/DOT at the mass proportion of 7/3 according to the American Wood Protection Association AWPA standard "AWPA P17-98" formula design shows good flame retardant synergistic effect of Pinus sylvestris with the results of LOI reaching 44.6%, vertical flame test of V-0 and heat release rate HRR, total heat release THR, total smoke release TSP and other parameters decrease.Meanwhile, DOT could increase the solubility and dissolution rate of GUP, shorten the dissolution time of GUP and DOT.