硅烷-二氧化硅气凝胶颗粒不同复配比例浸渍处理对增强杨木阻燃性能的影响

Effects of Different Compounding Ratios of Silane-Silica Aerogel Particles by Immersion Treatment on the Enhancement of Flame Retardant Properties of Populus adenopoda

以γ-缩水甘油基氧基丙基三甲氧基硅烷水解液(GPS)、二氧化硅气凝胶(SA)为改性剂原料,在质量分数为30%的GPS水解液中,加入占GPS质量2%、4%、6%、8%、10%的SA颗粒,制备复合改性的浸渍液;以杨木(Populus adenopoda)木材为试材,采用对木材试件进行真空加压浸渍处理方法,使用不同配比的复合改性的浸渍液浸渍处理木材试件制备5种复合改性浸渍液的改性木材、使用GPS水解液浸渍处理木材试件制备GPS改性木材、使用占GPS质量6%的SA水溶液浸渍处理木材试件制备SA改性木材;按照相关标准和试验方案,测定改性材的质量增加率、浸渍液流失率、微观形貌、隔热性能、表面接触角、硅元素化学组分构成、热稳定性、燃烧性能,分析硅烷-二氧化硅气凝胶颗粒不同复配比例浸渍处理杨木对增强杨木阻燃性能的影响。结果表明,GPS-SA复合改性有效改善了木材的疏水性,与单纯使用SA颗粒处理木材相比较,GPS-SA复合改性组水洗10 d后浸渍液流失率最高可降低了42%。扫描电镜分析结果表明,GPS主要在木材细胞腔中自聚形成大分子聚合物,而SA颗粒则主要附着于木材的导管上,且随着SA颗粒质量比例提高,SA颗粒团聚现象增加。GPS-SA复合改性后,木材的密度比未处理木材提高38%,而密度变大会导致热导率升高,但“GPS+占GPS质量6%的SA”组的热导率仍比未处理木材降低6%,且面积热容比未处理木材提高59%。热质量分析结果表明,GPS-SA处理,提高了木材的热解温度和剩余物质量。锥形量热仪分析结果表明,“GPS+占GPS质量6%的SA”处理木材比未处理木材的点燃时间滞后28s、热释放速率峰值下降44.5%、热释放总量下降47.8%、烟释放速率峰值降低29.4%、烟释放总量减少39.1%,处理材的CO、CO_(2)产量也明显比未处理材少。综合研究结果,GPS-SA复合处理能有效改善木材阻燃性能,并且制备方法简洁环保。

Using γ⁃glycidoxypropyltrimethoxysilane(GPS)hydrolyzate and silica aerogel(SA)as modification materials,a composite modified impregnating solution was prepared by adding 2%,4%,6%,8%,and 10%by mass of SA particles to 30%mass fraction GPS hydrolyzate.Populus adenopoda wood was used as the test material.It was treated with a vacuum pressure impregnation method using different ratios of composite modified impregnating solutions to prepare five types of mod⁃ified wood.Prepare GPS-modified wood by treating wood specimens with GPS hydrolyzate,and SA-modified wood by trea⁃ting wood specimens with 6%mass SA aqueous solution.According to relevant standards and test methods,the mass gain rate,impregnating solution loss rate,microstructure,thermal insulation performance,surface contact angle,silicon element chemical composition,thermal stability and combustion performance of the modified materials were determined.The impact of different compounding ratios of the silane⁃silica aerogel particle impregnation on the enhancement of flame retardant proper⁃ties of P.adenopoda was analyzed.The results showed that the GPS-SA composite modification effectively improved the hy⁃drophobicity of wood.The composite modification resulted in a reduction in impregnating solution loss rate after 10 days of water washing,compared to the use of SA alone,with the highest reduction being 42%for the GPS-SA composite modifica⁃tion.Scanning electron microscopy analysis indicated that GPS mainly self⁃polymerizes to form large polymer molecules in the wood cell lumen,while SA particles mainly adhere to the wood vessels.With increasing mass ratio of SA particles,aggrega⁃tion of SA particles also increased.After GPS-SA composite modification,the density of wood increased by 38%compared to untreated wood.While an increase in density leads to higher thermal conductivity,the thermal conductivity of the“GPS+6%mass SA”group was still 6%lower than that of untreated wood.In addition,the heat capacity of the composite modified wood was increased by 59%compared to the untreated wood.Thermal mass analysis results showed that GPS-SA treatment in⁃creased the wood’s thermal decomposition temperature and residual mass.Cone calorimetry analysis results showed that the“GPS+6%mass SA”treated wood had a 28⁃second delay in ignition time,a 44.5%decrease in peak heat release rate,a 47.8%decrease in total heat release,a 29.4%decrease in peak smoke release rate,and a 39.1%decrease in total smoke re⁃lease,compared to untreated wood.The CO and CO_(2) yield of treated materials was also significantly lower than that of un⁃treated materials.The comprehensive research results showed that GPS-SA composite treatment effectively improves the flame retardant properties of wood,and the preparation method is simple and environmentally friendly.