Study on degradation of phosphorus and nitrogen composite UV-cured flame retardant coating on wood surface
Study on degradation of phosphorus and nitrogen composite UV-cured flame retardant coating on wood surface
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木材表面磷氮复合紫外光固化阻燃涂料的降解研究
DOI：
10.1016/j.porgcoat.2018.08.017
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发表时间：
2018-11-01
影响因子：
6.6
通讯作者：
Guo, Chuigen
中科院分区：
文献类型：
--
作者：
Wang, Tiansheng;Liu, Tao;Guo, Chuigen
以丙烯酸酯低聚物和含磷、氮、硫元素的功能单体为原料，通过硫醇-烯点击反应，制备了一种新型木材阻燃涂料，并应用于木材表面。分别采用UL-94、极限氧指数（LOI）测试和热重分析/红外光谱（TGA-FTIR）来检测涂层的可燃性和热解性能。实验数据表明，当磷、氮单体摩尔比为2:4时，涂料在木材表面具有较好的防火性能。通过TGA-FTIR证实涂料降解过程中产生的挥发产物为羧酸、氨(NH3)、二氧化碳(CO2)和酸酐，最大释放速率对应的温度分别为99.80℃、170.96℃、346.75℃和500.75℃。分别为 358.80 摄氏度。此外，涂层在降解过程中释放出NH3和CO2等不燃气体，稀释了燃烧过程中的氧气浓度，有利于膨胀炭层的生成。涂层的TGA曲线显示出三个降解过程，分别对应于交联网络的失水和C-S键断裂、磷酸酯和丙烯酸酯的降解、不稳定炭层的分解、聚N,N-二甲基丙烯酰胺(PDMAA)中的主链和聚磷酸的形成。涂层在氮气气氛下600℃时的成炭率达到27.16%，表现出优异的阻燃性能。
A novel wood flame retardant coating has been obtained using acrylate oligomers and functional monomers containing elements phosphorus, nitrogen and sulfur as raw materials and applied on the wood surface based on thiol-ene click reaction. The UL-94, limiting oxygen index (LOI) test and thermal gravimetric analysis/infrared spectroscopy (TGA-FTIR) were used to examine the flammability and pyrolysis property of the coatings, respectively. The experimental data showed that the coating has better fire resistance on wood surface when the molar ratio of phosphorus and nitrogen monomer was 2: 4. The volatile products generated in the degradation processes of the coating were confirmed by TGA-FTIR, which are carboxylic acid, ammonia (NH3), carbon dioxide (CO2) and acid anhydride, with a temperature of maximum release rate corresponds to 99.80 degrees C, 170.96 degrees C, 346.75 degrees C and 358.80 degrees C, respectively. In addition, the coating released NH3 and CO2 as nonflammable gases during the degradation process, which diluted the oxygen concentration during combustion and was favorable to generate the intumescent char layer. The TGA curves of the coating showed three degradation, corresponding to the water loss and the C-S bond breaking of crosslinking networks, the degradation of phosphate and acrylates, the decomposition of unstable char layers, the main chain in poly N, N-dimethylacrylamide (PDMAA) and the formation of poly (phosphoricacid), respectively. The char yield of the coating reaches to 27.16% at 600 degrees C under nitrogen atmosphere, showing excellent flame retardant properties.