【作者】 王奉强；

【导师】 王清文； 王向明；

【作者基本信息】 东北林业大学 ， 木材科学与技术， 2011， 博士

【摘要】 社会物质文明不断进步,木质纤维材料得到更加广泛的使用,随之而来的火灾事故也频繁发生,木质纤维材料的阻燃研究和应用需求日益加剧。本文以磷-氮-硼复合阻燃剂为研究的主要切入点,结合前人对木材阻燃剂的科研成果和本课题组的研究积累,设计合成出以羟甲基化磷酸脒基脲(G21)和硼酸为主要阻燃活性物质的磷-氮-硼复合木材阻燃剂G21BA,从羟甲基化磷酸脒基脲的合成及表征、羟甲基化磷酸脒基脲和G21BA对胶合板的阻燃作用和热重分析、以及可控气氛锥形量热仪的火灾环境模拟的角度,展开了较为系统的阻燃性能评价和分析论述。以高纯度磷酸脒基脲(GUP)、甲醛和水为主要原料,控制反应条件使之完全反应,得到羟甲基化磷酸脒基脲,其具有溶液无色澄清透明、溶解性提高、酸碱性温和、吸湿性低、有一定抗流失性等特点。经FTIR和XRD分析表征,伯酰胺红外吸收峰减弱,羟甲基峰出现,说明在磷酸脒基脲分子上成功接上羟甲基,且随羟甲基化程度的增大,伯酰胺吸收峰逐渐消失,产物的无定形聚集态结构特征更加明显。TG结果显示其起始分解温度降低,但最终残余物质量分数较GUP稍有提高。CONE测试结果显示,随羟甲基化程度的增大,处理胶合板的热释放、烟释放和火势增长指数稍有提高,相对GUP的阻燃和抑烟效果,G21与之相当。采用复配技术制得G21BA阻燃剂,其在胶合板内部颗粒细密且分散均匀,具有较强的阻燃和抑烟性能,且力学性能得到一定程度的改善。可控气氛锥形量热仪模拟开放式火灾环境和相对封闭的室内火灾环境,结果表明,在开放式火灾环境中,G21BA阻燃胶合板的热释放量、质量损失率、火势增长指数、发烟量以及烟气毒性均降低。在相对封闭的室内火灾环境中,G21BA阻燃胶合板在低氧浓度环境中的发烟量和CO释放比在较高氧浓度条件下明显提高,而胶合板素材在较高氧浓度下的发烟量和热释放相对低氧浓度大大增大。G21BA阻燃胶合板在空气氧浓度高于18%时,与胶合板素材相比具有显著的阻燃和抑烟效果。G21BA阻燃胶合板的使用安全性得到大大提高。在相对封闭的室内,由于堆放较多易燃物而发生火灾并引燃所大量使用的G21BA阻燃胶合板,若环境严重缺氧则会生成较多CO气体和浓烟,为消防安全带来不利影响,因此建议在人员活动频繁并大量使用G21BA阻燃胶合板的公共场合,不宜堆放太多易燃物品。G21BA对胶合板主要是凝聚相阻燃机理,即在高温下使胶合板发生脱水、分解、缩合、聚合、芳构化等反应而快速成炭；另外G21BA分解出的水、氨气等不燃性气体对稀释周围氧气浓度也起到一定的阻燃作用,并且G21和硼酸的热解产物在高温下产生的磷酸硼可能会对抑制红热燃烧起到一定的物理覆盖和热屏蔽作用。更多还原

【Abstract】 Lignocellulosic materials are more widely used along with the progress of the social material civilization. The fire disaster may occur frequently because of the use of this flammable material. The requirement of fire-retardant lignocellulosic materials’research and application is increasing.This paper combined the previous scientific research and our research accumulates about wood fire retardant based on phosphorus-nitrogen-boron fire retardant composites. A phosphorus-nitrogen-boron fire retardant complex G21BA was synthesized, which is mainly composed of methylolated guanylurea phosphate G21 and boric acid as fire retardant active substances. Systematic evaluation of its fire performance was performed by thermogravimetric analysis (TGA) of plywood treated with methylolated guanylurea phosphate and G21BA, the controlled atmosphere cone calorimeter analysis, and the fire retardant mechanism was discussed.By using the complete reaction of high pure guanylurea phosphate (GUP), formaldehyde and water at a controlled reaction condition, methylolated guanylurea phosphates were synthesized with different hydroxymethyl content. The characteristics of methylolated GUP are that the colorless clear solution, the enhanced solubility, the mild acidity, the low hygroscopicity and better leachability. The FTIR analysis results of methylolated GUP showed that the intensity of the primary amide absorption peak decreased compared to GUP and the hydroxyl methyl peak appeared, explaining the hydroxyl methyl group being grafted successfully on to GUP. Along with the increasing methylolated degree, the primary amide infrared absorption peak gradually disappeared. The X-Ray Diffraction (XRD) result showed the amorphous state structure of methylolated GUP is more apparent. TGA results showed that the initial decomposition temperature of methylolated GUP is lower than GUP, but eventually the residue mass fraction is slightly more than GUP. CONE testing results showed that the heat release, smoke release and fire growth index were increasing slightly along with the increasing methylolated degree. G21, which was synthesized from 2 mole GUP and 1 mole formaldehyde, was basically the same with GUP on fire-retardant and smoke inhibiting effect.Plywood was impregnated with G21BA aqueous solution. Tiny particles were found on the cell wall in dry plywood treated with G21BA, which were arranged very closely and scattered evenly. The fire-retardant and smoke inhibition performances were very strong and the plywood’s mechanical properties had been improved by G21BA. The open fire environment and the relative close indoor fire environment were simulated by controlled atmosphere cone calorimeter. At the open fire environment, the cone results showed that the heat release, mass loss ratio, fire growth index, smoke product and toxicity of G21BA fire-retardant plywood were obviously lower than untreated plywood. In the relative close indoor fire environment, the smoke product and CO release under low oxygen concentration of G21BA fire-retardant plywood were obviously higher than that under high oxygen concentration. Meanwhile, the smoke product and heat release under high oxygen concentration of untreated plywood increased greatly compared with low oxygen concentration. When the oxygen concentration in the air was higher than 18%, the fire-retardant and smoke inhibition properties of G21BA fire-retardant plywood were lower greatly than untreated plywood, and the usage safety of G21BA fire-retardant plywood was improved significantly. In the relative close indoor, the G21BA fire-retardant plywood may be ignited by the fire caused by stacked much more inflammables. It would release much CO and heavy smoke if oxygen concentration in the air was very low. Therefore, we suggest that do not pile up too many flammable materials in the public places where much amount of G21BA treated plywood was used and human activities are frequent.G21BA fire-retardant mechanism on plywood mainly is condensed-phase fire-retardant mechanism. When plywood was heated to high temperature, dehydration, decomposition, condensation, polymerization, aromatization reaction was took place and formed charcoal rapidly. In addition, the non-flammable gas (such as water vapor and ammonia) formed during the decomposition of G21BA could play a role of fire-retardant effectively through diluting the oxygen concentration. The pyrolysis products from G21 and boric acid at high temperature may form boron phosphate which plays a certain physical cover and heat shielding effect to inhibit red-hot combustion.更多还原