混晶TiO2制备木结构防火涂料及阻燃机理

以KOH和Na₂SiO₃改性硅灰为基料，通过溶胶-凝胶法制备水性木结构阻燃涂料。制作三聚氰胺饰面中密度纤维板试件，测量试件的氧指数，分析试样及原料的晶相变化及表观形貌，研究板钛矿/锐钛矿混晶TiO₂对其阻燃性能及微观结构的影响。结果表明，适量的TiO₂可提高其阻燃性能，当TiO₂掺量为2%时其阻燃性能最佳，可使纤维板的LOI达到31.4%，炭化体积(小室法）仅为8.2 cm³，较不添加TiO₂的样品减小了56%。混晶TiO₂在燃烧处理过程中结构稳定，有助于硅灰基水性木结构阻燃涂料在燃烧过程中发展成连续、均匀、密实的片层状结构，致使失重温度升高，热流量减小，进而提高阻燃性能。

Preparation and flame retardant mechanisms on wood coatings with hybrid TiO2

Waterborne wood flame-retardant coating were investigated with KOH/Na2SiO3 modified silica fume as binder through sol-gels method.Melamine faced MDF test pieces were made and the oxygen index of the test piece was measured.Analysis of crystal phase change and apparent morphology of samples and raw materials were carried out to research the effects of brookite/anatase TiO2 on flame retardant properties and microstructure.The results showed that the amount of TiO2 could improve the flame retardant performances,it displayed the optimum flame retardant performance for the specimen with 2%mass fraction of TiO2,the LOI of fiberboard reached 31.4%,the burning volume(Small chamber method)was only 8.2 cm^3,it decreased by 56%in comparison with the specimen without TiO2.The brookite/anatase TiO2 holds a stable structure during the combustion process,which is benefit for silica fume-based waterborne wood coatings to develop complete,uniform,denser layer structures,leading to an increase in the weight loss temperature and a decrease in heat flow,therefore it improves the flame retardant performance.