Mg/Al-LDHs纳米阻燃剂的制备及其在 饰面人造板中的应用

人造板属于易燃材料,其燃烧往往是引起火灾的主要原因,对居住环境安全有极大的威胁。研究开发新型阻燃剂,对有效降低人造板的燃烧速率、降低火焰传播速度和减少人造板在燃烧过程中产生的有害烟气等具有重要的意义。以六水合硝酸镁和九水合硝酸铝为原料,采用共沉淀法制备Mg/Al层状双金属氢氧化物(layered double hydroxides,LDHs),对其结构和热稳定性进行表征,然后将其与三聚氰胺甲醛树脂复合,并将复合物应用于饰面人造板中,研究其对板材力学性能和阻燃性能的影响。结果表明:所合成的LDHs结晶度较高,尺寸达到纳米级别,且具有良好的层状结构; 与空白样相比,添加7% LDHs阻燃剂的饰面刨花板点燃时间延长3 s、热释放速率峰值降低6.80%、有效燃烧热峰值降低7.48%、释热总量降低9.97%、二氧化碳产率峰值降低4.62%、一氧化碳产率峰值降低44%,起到了一定的阻燃抑烟效果。
Since wood-based panels are inflammable and unsafe, it is important to explore a new flame retardant for reducing the rate of burning, speed of flame propagation and production of harmful smoke. In this paper, Mg/Al-layered double hydroxides were synthesized with Mg(NO3)2？6H2O and Al(NO3)3？9H2O via the co-precipitation method and characterized with respects of structure and thermal stability. Then Mg/Al-LDHs were compounded with the melamine formaldehyde resin. The film paper was immersed in the mixture and then faced on the panel surface to prepare veneer wood-based panels. This paper was aimed at investigating the effect of Mg/Al-LDHs as a newly developed flame retardant on the mechanical properties and flame retardant properties of the veneer wood-based panels, in order to achieve excellent flame retardant performance without compromising the physical and mechanical properties of the panels. The results of XRD showed that the degree of crystallinity of LDHs was as high as 88.07%, with a particle size of less than 100 nm(nanoscale)and great multiple-layered structure. The results of the cone calorimeter showed that, compared with the control sample, TTI(time to ignite)of the resulted panels increased 3 s, the peak of heat release rate(pkHRR)reduced by 6.80%, peak of effective heat combustion(pkEHC)reduced by 7.48%, THR(total heat release)reduced by 9.97%, pkPCO2(peak of production CO2)reduced by 4.62% and pkPCO(peak of production CO)reduced by 44% because of the addition of 7% LDHs retardant. In summary, Mg/Al-LDHs synthesized by co-precipitation method was able to reduce the degree of combustion and the concentration of smoke to some extent, which can be used for the veneer wood-based panels as an effective flame retardant without compromising the physical and mechanical properties of the panels