Marset David, Dolza Celia, Fages Eduardo, Gonga Eloi, Gutiérrez Oscar, Gomez-Caturla Jaume, Ivorra-Martinez Juan, Sanchez-Nacher Lourdes, Quiles-Carrillo Luis
Textile Industry Research Association (AITEX), Plaza Emilio Sala 1, 03801 Alcoy, Spain.
Technological Institute of Materials (ITM), Universitat Politècnica de València (UPV), Plaza Ferrándiz y Carbonell 1, 03801 Alcoy, Spain.
Polymers (Basel). 2020 Dec 19;12(12):3050. doi: 10.3390/polym12123050.
The main objective of the work reported here was the analysis and evaluation of halloysite nanotubes (HNTs) as natural flame retardancy filler in partially biobased polyamide 610 (PA610), with 63% of carbon from natural sources. HNTs are naturally occurring clays with a nanotube-like shape. PA610 compounds containing 10%, 20%, and 30% HNT were obtained in a twin-screw co-rotating extruder. The resulting blends were injection molded to create standard samples for fire testing. The incorporation of the HNTs in the PA610 matrix leads to a reduction both in the optical density and a significant reduction in the number of toxic gases emitted during combustion. This improvement in fire properties is relevant in applications where fire safety is required. With regard to calorimetric cone results, the incorporation of 30% HNTs achieved a significant reduction in terms of the peak values obtained of the heat released rate (HRR), changing from 743 kW/m to about 580 kW/m and directly modifying the shape of the characteristic curve. This improvement in the heat released has produced a delay in the mass transfer of the volatile decomposition products, which are entrapped inside the HNTs' lumen, making it difficult for the sample to burn. However, in relation to the ignition time of the samples (TTI), the incorporation of HNTs reduces the ignition start time about 20 s. The results indicate that it is possible to obtain polymer formulations with a high renewable content such as PA610, and a natural occurring inorganic filler in the form of a nanotube, i.e., HNTs, with good flame retardancy properties in terms of toxicity, optical density and UL94 test.
本文所报道工作的主要目标是分析和评估埃洛石纳米管（HNTs）作为部分生物基聚酰胺610（PA610）中的天然阻燃填料的性能，PA610中63%的碳来自天然来源。HNTs是一种天然存在的具有纳米管形状的粘土。通过双螺杆同向旋转挤出机获得了含有10%、20%和30% HNT的PA610复合材料。将所得共混物注塑成型以制备用于燃烧测试的标准样品。在PA610基体中加入HNTs可降低燃烧过程中的光密度，并显著减少有毒气体的排放。在需要消防安全的应用中，这种燃烧性能的改善具有重要意义。关于锥形量热结果，加入30%的HNTs使热释放速率（HRR）的峰值显著降低，从743 kW/m²降至约580 kW/m²，并直接改变了特征曲线的形状。热释放的这种改善导致挥发性分解产物的质量传递延迟，这些产物被困在HNTs的管腔内，使样品难以燃烧。然而，关于样品的点火时间（TTI），加入HNTs使点火开始时间减少了约20秒。结果表明，有可能获得具有高可再生含量的聚合物配方，如PA610，以及以纳米管形式存在的天然无机填料，即HNTs，其在毒性、光密度和UL94测试方面具有良好的阻燃性能。
