Unraveling thermo-oxidation degradation pathways of polymers by in-situ differentiating the alkyl-related reactive oxygen radicals

IF 13.2 1区工程技术 Q1 ENGINEERING, CHEMICAL Chemical Engineering Journal Pub Date : 2025-04-22 DOI:10.1016/j.cej.2025.162951

Yue Hou, Jiao Li, Guofeng Tian, Rui Tian, Chao Lu

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引用次数: 0

Abstract

Alkoxy radicals (RO•) and peroxy radicals (ROO•) are generated during thermo-oxidation of polymers under oxygen environment, leading to RO•-dominated or ROO•-dominated reaction pathways with severely deteriorated polymer chains or terminated reaction. However, it has been a long-standing challenge to in-situ distinguish RO• and ROO• radicals due to their short-lived lifetime. In principle, chemiluminescence (CL) deserves to become an efficient strategy for in-situ monitoring for various radicals. However, it fails to differentiate RO• and ROO• radicals due to their fully overlapping emission wavelengths. In this contribution, we have proposed a CL dynamic fitting strategy to distinguish RO• and ROO• radicals of in-situ production during thermal oxidation under the different oxygen-containing environment. Based on two equations,

\ln I = \ln A \cdot k_{RO} - \ln (1 + Y \cdot e^{- k_{RO} t}), a n d \ln I = \ln B - k_{ROO} t - 2 \ln (1 + Y \cdot e^{- k_{ROO} t})

$\ln I = \ln A \cdot k_{RO} - \ln (1 + Y \cdot e^{- k_{RO} t}), a n d \ln I = \ln B - k_{ROO} t - 2 \ln (1 + Y \cdot e^{- k_{ROO} t})$ , respectively, the CL dynamic fitting was implemented to identify RO• and ROO• generated during the oxidative reactions of polymers. It is anticipated that the proposed strategy could be further explored for the identification of other radicals during thermo-oxidation, providing possibilities for regulating oxidative reaction pathways of polymers.

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通过原位区分烷基相关活性氧自由基，揭示聚合物的热氧化降解途径

聚合物在氧气环境下发生热氧化反应时会产生烷氧基自由基（RO-）和过氧自由基（ROO-），从而导致以 RO- 为主或以 ROO- 为主的反应途径，使聚合物链严重恶化或反应终止。然而，由于 RO- 和 ROO- 自由基的寿命很短，要在原位区分它们一直是个难题。原则上，化学发光（CL）理应成为原位监测各种自由基的有效策略。然而，由于 RO- 和 ROO- 自由基的发射波长完全重叠，因此无法将它们区分开来。在本文中，我们提出了一种 CL 动态拟合策略，用于区分不同含氧环境下热氧化过程中原位产生的 RO- 和 ROO- 自由基。基于两个方程：lnI=lnA-kRO-ln1+Y-e-kROt,和lnI=lnB-kROOt-2ln1+Y-e-kROOtlnI=lnA-kRO-ln1+Y-e-kROt,和lnI=lnB-kROOt-2ln1+Y-e-kROOt，实现了 CL 动态拟合，以识别聚合物氧化反应过程中产生的 RO- 和 ROO-。预计所提出的策略可进一步用于识别热氧化过程中的其他自由基，为调节聚合物的氧化反应途径提供可能性。

本文章由计算机程序翻译，如有差异，请以英文原文为准。

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来源期刊

Chemical Engineering Journal 工程技术-工程：化工

CiteScore

21.70

自引率

9.30%

发文量

6781

审稿时长

2.4 months

期刊介绍： The Chemical Engineering Journal is an international research journal that invites contributions of original and novel fundamental research. It aims to provide an international platform for presenting original fundamental research, interpretative reviews, and discussions on new developments in chemical engineering. The journal welcomes papers that describe novel theory and its practical application, as well as those that demonstrate the transfer of techniques from other disciplines. It also welcomes reports on carefully conducted experimental work that is soundly interpreted. The main focus of the journal is on original and rigorous research results that have broad significance. The Catalysis section within the Chemical Engineering Journal focuses specifically on Experimental and Theoretical studies in the fields of heterogeneous catalysis, molecular catalysis, and biocatalysis. These studies have industrial impact on various sectors such as chemicals, energy, materials, foods, healthcare, and environmental protection.