CS/h BN/APP层层自组装涂层阻燃杨木的研究

Effect of CS/h BN/APP Coating by LBL Technology on Flame Retardant Poplar

关键词:  杨木  六方氮化硼  聚磷酸铵  阻燃  层层自组装

Key words:  poplar  h BN  APP  flame retardancy  layer by layer self assembly

摘要:

为提高杨木的阻燃性能,利用带正电性的壳聚糖/六方氮化硼(CS/h BN)聚电解质溶液,以及带负电性的聚磷酸铵(APP)溶液,基于层层自组装(LBL)技术,通过两聚电解质溶液之间的静电吸附作用,在木材表面成功制备出具有良好阻燃性能的CS/h BN/APP薄膜涂层.结果表明：所制备的涂层均匀分布在木材表面,且具有良好的附着力;涂层阻燃木材试件的热释放速率、烟释放速率显著降低,第2放热峰出现时间晚于未处理木材试件,且在燃烧过程中的残余物质量始终高于未处理木材试件,完全燃尽时间则比未处理木材试件多出约100s,阻燃效果随着自组装涂层数的增加而逐渐增强;涂层阻燃木材试件的CO、CO2气体生成量明显降低,表明阻燃涂层能有效降低木材烟气及毒性气体释放;涂层阻燃木材试件较未处理木材试件更好地保持了木材本身的结构,显示出了良好的抵抗火灾能力.

Abstract:

In order to improve the flame retardancy of the poplar, CS/h BN/APP thin films with good flame retardant properties are successfully prepared on the wood surface through electrostatic adsorption between the positively charged chitosan/hexagonal boron nitride(CS/h BN) polyelectrolyte solution and the negatively charged ammonium polyphosphate(APP) solution based on the layer by layer self assembly(LBL)technology. The characterizations of scanning electron microscope(SEM) and energy dispersive spectrum(EDS) indicate that CS/h BN/APP coatings have equably spread over the surface of wood. Coating adhesion test indicates that the coating has excellent adhesion performance. Cone calorimeter tests show that heat release rate(HRR) and smoke production rate(SPR) of assembled wood samples are all significantly reduced, the second peak heat release rate(Pk HRR) and peak smoke production rate(Pk SPR) appear later than that of the untreated woods. During the combustion, residual mass of the assembled wood samples is always higher than that of the untreated woods and the time to burn out is about 100s more than that of untreated woods, and the effect is gradually enhanced with the increase of the number of self assembly layers. The production of CO and CO2gas of the assembled wood samples are significantly reduced, indicating the flame retardant coating can effectively reduce wood smoke and toxic gases release. The char residue indicates that the assembled wood samples preserve the structure of the wood better than that of the untreated woods, showing a good fire resistance.