复合硅改性热处理杨木的制备及性能

目的]针对木材树脂改性剂释放甲醛不环保,无机改性材吸湿性高等问题,将廉价易得的硅石粉溶液化,再有机杂化,制得高渗透、环保、防火的水溶性木材复合硅改性剂,通过真空加压浸渍处理和热处理联合改性,可以有效提高木材的物理力学和阻燃等性能.方法]分别制备硅油复合硅改性剂(SC2)和偶联剂杂化硅改性剂(HS2),对人工林杨木进...

Preparation and properties of heat-treated poplar wood modified with composite silicon modifier

Objective]Considering the problems such as formaldehyde emission from wood resin modifier and high hygroscopicity of inorganic material modified wood,the easily available silica powder was used as the main raw material to prepare composite silicon wood modifier,which was water-soluble,high permeable,environmental friendly and fireproof.Through vacuum pressure impregnation and heattreatment,the physical,mechanical and fire retardant properties of woods were effectively improved.Method]Silicone oil composite silicon modifier(SC2)and coupling agent hybrid silicon modifier(HS2) were prepared respectively. Plantation poplar wood was impregnated, then the impregnated wood was heattreatedat a high temperature. The physical, mechanical and fire retardant properties of composite siliconmodified wood and its heat-treated wood were finally tested and analyzed. Result] After heat-treatment,the mass and oven-dry density of all samples decreased, and the oven-dry density loss rate and mass loss rateof heat-treated silicone oil composite silica modified wood (TW-SC2) were the largest. Compared withsilicone oil composite silicon modified wood (W-SC2), the moisture absorption rate of TW-SC2 increased.The moisture absorption rate of the heat-treated coupling agent hybrid silica modified wood (TW-HS2) wassignificantly lower than that of the coupling agent hybrid silicon modified wood (W-HS2), and the moistureabsorption resistance was significantly improved. Compared with the untreated wood (W), the mechanicalproperties of all the modified wood apparently improved, and were better than TW-SC2. The ignition time ofW-HS2 was 8 s later than that of W, its fire performance index increased from 0.043 to 0.140 m2s/kW. Theignition time of TW-HS2 was 9 s later than that of W, and its fire performance index increased by 64.3%compared with W-HS2. Compared with W, the total heat release of TW-HS2 reduced by 29.4%, the peakheat release rate decreased, and the peak time of the second heat release rate was delayed. The total smokerelease of W-HS2 or TW-HS2 was larger than that of W, the HS2 impregnation modification combined withheat-treatment can further promote the flame retardancy of wood. The thermal degradation rate of themodified wood was significantly lower than that of W, and the thermal stability was improved, indicatingthat the HS2 modifier had a significant effect on promoting char formation. Conclusion] Taking silica asraw material, the coupling agent hybrid silicon modifier HS2, which was environmentally friendly and highlyefficient, was prepared through organic hybridization. The combined modification process of vacuumpressure impregnation and heat-treatment can effectively improve the mechanical and fire-retardantproperties of plantation poplar wood, realize green modification with broad application prospects.