At elevated temperatures, polyethylene terephthalate (PET) is known to undergo a cascade of interconnected chemical reactions, in particular oxidative crosslinking, which can lead to severe limitations in processability, product properties, and recyclability. To control such undesired reactions, a newly synthesized phosphorus-based additive with promising flame retardant properties (T. Stelzig et al. Dopo-Based Hybrid Flame Retardants. EP2921498 (A1), 2015), by the chemical name 6-((1-oxido-2,6,7-trioxa-1-phosphabicyclo[2.2.2]octan-4-yl)methoxy)dibenzo[c,e][1,2]oxaphosphinine 6-oxide (DOPO-PEPA, or simply DP), was added to PET in different concentrations. To assess the miscibility of DP and PET at the nanoscale, a multiscale simulation scheme was developed by combining molecular dynamics and dissipative particle dynamics. DP showed a prominent inter-chain lubrication effect in PET in extrusion experiments. To replicate the heating cycles during repeated recycling, the thermal stability of PET melts was assessed on extended timescales using rheological measurements. Time-resolved frequency sweep experiments were conducted with or without the novel DP additive, under air and nitrogen atmospheres. By combining various chemical analysis techniques, a chemical stabilizing mechanism could be proposed that describes how the DP molecule intervenes with the degenerative chemical reactions of PET chains in the melt processing phase. The proposed mechanism outlines trace-release from DP involving the formation of phosphorus radicals including DOPO^•, PEPA^•, and PO^•. Such radicals scavenge the oxygen radicals from air and can thus protect the linearity of PET chains. The results underline the synergistic effects of DP on the processing of high performance PET. Together with flame retardancy of the original product, the environmental-friendly DP chemically-protects and lubricates PET during subsequent recycling of the waste.

已知在升高的温度下，聚对苯二甲酸乙二酯（PET）会经历一连串的相互连接的化学反应，尤其是氧化交联，这会导致严重限制加工性，产品性能和可回收性。为了控制这种不希望的反应，使用了一种新合成的磷基添加剂，该添加剂具有良好的阻燃性能（T.Stelzig等。基于Dopo的混合阻燃剂.EP2921498（A1），2015），化学名称为6-（（1-氧化-2,6,7-三氧杂-1-膦双环[2.2.2]辛烷-4​​-基）甲氧基）二苯并[c，e] [1,2]氧杂膦6氧化物（DOPO-PEPA或简称DP） ，以不同的浓度添加到PET中。为了评估DP和PET在纳米级的可混溶性，通过结合分子动力学和耗散粒子动力学，开发了一种多尺度模拟方案。在挤出实验中，DP在PET中显示出显着的链间润滑效果。为了复制重复循环过程中的加热循环，使用流变学方法在延长的时间范围内评估了PET熔体的热稳定性。在空气和氮气气氛下，在有或没有新型DP添加剂的情况下进行了时间分辨的频率扫描实验。通过结合各种化学分析技术，可以提出一种化学稳定机制，该机制描述了DP分子如何在熔融加工阶段与PET链的退化化学反应进行干涉。拟议的机制概述了从DP释放的痕量，涉及包括DOPO在内的磷自由基的形成 PET熔体的热稳定性在较长的时间范围内使用流变学测量进行了评估。在空气和氮气气氛下，在有或没有新型DP添加剂的情况下进行了时间分辨的频率扫描实验。通过结合各种化学分析技术，可以提出一种化学稳定机制，该机制描述了DP分子如何在熔体加工阶段与PET链的退化化学反应进行干涉。拟议的机制概述了从DP释放的痕量，涉及包括DOPO在内的磷自由基的形成 PET熔体的热稳定性在较长的时间范围内使用流变学测量进行了评估。在空气和氮气气氛下，在有或没有新型DP添加剂的情况下进行了时间分辨的频率扫描实验。通过结合各种化学分析技术，可以提出一种化学稳定机制，该机制描述了DP分子如何在熔体加工阶段与PET链的退化化学反应进行干涉。拟议的机制概述了从DP释放痕量释放，涉及包括DOPO在内的磷自由基的形成 可以提出一种化学稳定机制，该机制描述DP分子如何在熔融加工阶段与PET链的退化化学反应之间进行干涉。拟议的机制概述了从DP释放的痕量，涉及包括DOPO在内的磷自由基的形成 可以提出一种化学稳定机制，该机制描述DP分子如何在熔融加工阶段与PET链的退化化学反应之间进行干涉。拟议的机制概述了从DP释放的痕量，涉及包括DOPO的磷自由基的形成^•，PEPA ^•和PO ^•。这种自由基清除空气中的氧自由基，从而可以保护PET链的线性。结果强调了DP对高性能PET加工的协同作用。结合原始产品的阻燃性，环保的DP在随后的废物回收过程中对PET进行化学保护和润滑。