Defang Zhao, Lin Li, Yu-hui Xie, Dong Feng, Feng Wu*, Delong Xie*, Yuxin Liu and Yi Mei,
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引用次数: 0
Abstract
Bio-based phosphorus flame retardants offer significant promise in enhancing the flame retardancy of bioplastics without compromising their environmental friendliness. In this study, a bio-based phosphorus-based flame retardant (PFR) synthesized from epoxidized soybean oil polyol (PESO) was used to enhance the flame-retardant properties of poly(lactic acid) (PLA), aiming to establish the correlation between phosphorus content and the fire behavior of PLA composites. Notably, the study determined that the critical phosphorus content value for improving the PLA rating from NR to V-0 was as low as 0.1 wt % in the composites, with the limited oxygen index (LOI) of PLA increasing from 21.0% to 25.2%. Meanwhile, the introduction of PESO with high phosphorus contents decreased the peak heat release rate (PHRR) and total heat release (THR) of PLA by 5.33% and 9.66%, respectively. Nevertheless, with the complete replacement of the epoxy group by phosphorus ring-opening, PESO loses its plasticizing effect, making it challenging to enhance the elongation at the break of PLA. Finally, the flame-retardant mechanism of PLA/PESO composites was comprehensively analyzed. It was found that the mechanism was also related to the phosphorus contents; high phosphorus was not favorable for the char forming in the condensed phase but promoting the melt dripping and formation of PO•, PO2•, and HPO• which could trap radicals in the gas phase. This study provides valuable insights into designing PFRs from renewable resources for PLA.
期刊介绍:
ACS Applied Polymer Materials is an interdisciplinary journal publishing original research covering all aspects of engineering, chemistry, physics, and biology relevant to applications of polymers.
The journal is devoted to reports of new and original experimental and theoretical research of an applied nature that integrates fundamental knowledge in the areas of materials, engineering, physics, bioscience, polymer science and chemistry into important polymer applications. The journal is specifically interested in work that addresses relationships among structure, processing, morphology, chemistry, properties, and function as well as work that provide insights into mechanisms critical to the performance of the polymer for applications.