Jiangsu Co-Innovation Center of Efficient Processing and Utilization of Forest Resources, International Innovation Center for Forest Chemicals and Materials, College of Materials Science and Engineering, Nanjing Forestry University, Nanjing, Jiangsu, 210037, China.
Jiangsu Co-Innovation Center of Efficient Processing and Utilization of Forest Resources, International Innovation Center for Forest Chemicals and Materials, College of Materials Science and Engineering, Nanjing Forestry University, Nanjing, Jiangsu, 210037, China.
Environ Res. 2022 Oct;213:113724. doi: 10.1016/j.envres.2022.113724. Epub 2022 Jun 19.
Thermal and flame-retardant properties of traditional composites have limitations that are not satisfied for the various applications. Multilayered materials have great potential to improve material properties. The present paper focused on designing new multilayering approach to fabricate flame retardant multilayered materials with a very basic instrument and several simple steps. Montmorillonite nanoparticles filled maleic anhydride grafted polypropylene composites were prepared by the melt-blending method, and the multilayered composites with polypropylene alternating multilayers were fabricated by the quadruple-layering approach. The multilayer structure was characterized by the scanning electron microscopy/energy dispersive spectrometer. The influence of layer structure on the thermal stability, thermal conductivity and flame-retardant properties was investigated by the comparison with the conventional composites. Multilayered composites showed enhanced flame-retardant properties with lower peak heat release rate and better char formation compared to conventional composites with the same mass fraction of montmorillonite. Multilayered composites had higher mass fraction of montmorillonite in filled layers and no fillers in other layers, which caused the unequal distribution of montmorillonite, resulting in changes of thermal and flame-retardant properties of the materials especially in the perpendicular direction to the film surface. This study demonstrates a unique multilayering approach that has potential to be used in variety applications such as food and medical packaging.
传统复合材料的热学和阻燃性能存在局限性，无法满足各种应用的需求。多层材料具有改善材料性能的巨大潜力。本文主要介绍了一种新的多层设计方法，使用非常基本的仪器和几个简单的步骤来制备具有阻燃性能的多层材料。采用熔融共混法制备了蒙脱土纳米粒子填充马来酸酐接枝聚丙烯复合材料，并通过四层法制备了聚丙烯交替多层复合材料。采用扫描电子显微镜/能谱仪对多层结构进行了表征。通过与传统复合材料的对比，研究了层结构对热稳定性、热导率和阻燃性能的影响。与具有相同蒙脱土质量分数的传统复合材料相比，多层复合材料表现出更好的阻燃性能，其峰值放热率更低，炭层形成更好。多层复合材料在填充层中具有更高质量分数的蒙脱土，而在其他层中没有填充剂，这导致蒙脱土分布不均，从而改变了材料的热学和阻燃性能，尤其是在垂直于膜表面的方向上。本研究展示了一种独特的多层设计方法，具有在食品和医疗包装等多种应用中的潜力。
