This study investigates the concurrent improvement in fire safety and ductility of polylactic acid (PLA) through the incorporation of glycerol triglycidyl ether (Gte) as a novel biobased plasticizer and ammonium polyphosphate (APP) as a flame retardant. The PLA/Gte/APP composites were fabricated using a facile one-pot melt mixing approach and their rheological, mechanical, thermal properties, and flame retardancy were thoroughly assessed. The optimal composition with 15 phr Gte and 12 phr APP demonstrated a remarkable enhancement in PLA’s elongation at break by around 330 % and reached a V-0 rating in the UL-94 test with a Limiting Oxygen Index (LOI) of 28.9 %. The fire-retardant mechanism was elucidated by studying the residual char morphology and analyzing the volatilization products during pyrolysis, revealing that APP contributed to the generation of a dense carbon layer that plays the part of a thermal and oxygen barrier, while also releasing nonflammable gases to dilute the surrounding oxygen. The study presents a sustainable approach to producing flame-retardant and ductile PLA, positioning the PLA/Gte/APP12 composite as a potential material for industrial applications that demand high safety and high ductility.

中文翻译：

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生物基增塑剂可显着提高延展性的阻燃聚乳酸复合材料


本研究探讨了通过加入甘油三缩水甘油醚（Gte）作为新型生物基增塑剂和聚磷酸铵（APP）作为阻燃剂来同时提高聚乳酸（PLA）的防火安全性和延展性。 PLA/Gte/APP 复合材料采用简便的一锅熔融混合方法制造，并对其流变性、机械性能、热性能和阻燃性进行了彻底评估。含有 15 份 Gte 和 12 份 APP 的最佳组合物显示，PLA 断裂伸长率显着提高约 330%，并在 UL-94 测试中达到 V-0 等级，极限氧指数 (LOI) 为 28.9%。通过研究残余炭的形态并分析热解过程中的挥发产物，阐明了阻燃机理，揭示了 APP 有助于生成致密的碳层，起到热阻和氧阻隔的作用，同时还释放出不燃气体稀释周围的氧气。该研究提出了一种生产阻燃和延展性 PLA 的可持续方法，将 PLA/Gte/APP12 复合材料定位为需要高安全性和高延展性的工业应用的潜在材料。