Department of Polymer Science and Engineering, Pusan National University, Busan 46241, South Korea.
Department of Polymer Science and Engineering, Chonnam National University, Gwangju 61186, South Korea.
Carbohydr Polym. 2020 Oct 15;246:116628. doi: 10.1016/j.carbpol.2020.116628. Epub 2020 Jun 12.
We fabricate transparent cellulose nanopapers with significantly enhanced flame retardancy by a vacuum filtration assisted layer-by-layer deposition method. Flame retardancy is enhanced by increasing the layer-by-layer thickness while not hampering optical transparency of the nanopapers. Thermal degradation and combustion behaviors show that the nanopapers have been successfully functionalized by phosphorus and amine compounds that act effectively as intumescent and blowing agents. Based on the heat release rate of the various nanopapers herein, we propose that the area of the second peak in the heat release rate can serve as an indicator for coating efficiency of these flame retardant materials. We also suggest a possible mechanism behind the material's flame retardancy where by the phosphorus and blowing materials promote intumescent carbonaceous and porous char layers that prevent diffusion of oxygen and heat penetration into the underlying cellulose nanopapers.
我们采用真空过滤辅助层层沉积法制备了具有显著增强的阻燃性能的透明纤维素纳米纸。通过增加层层厚度来提高阻燃性能，同时不影响纳米纸的光学透明度。热降解和燃烧行为表明，磷和胺化合物已成功对纳米纸进行了功能化，它们作为膨胀和发泡剂可有效发挥作用。基于各种纳米纸的放热量，我们提出释放率的第二个峰值的面积可以作为这些阻燃材料的涂层效率的指标。我们还提出了这种材料阻燃性背后的一种可能机制，其中磷和发泡材料促进了膨胀的炭质和多孔炭层的形成，阻止了氧气的扩散和热量穿透到下面的纤维素纳米纸中。
