Carbon fiber-reinforced polymer (CFRP) materials are widely used in aerospace and recreational equipment, but there is no efficient procedure for their end-of-life recycling. Ongoing work in the chemistry and engineering communities emphasizes recovering carbon fibers from such waste streams by dissolving or destroying the polymer binding. By contrast, our goal is to depolymerize amine-cured epoxy CFRP composites catalytically, thus enabling not only isolation of high-value carbon fibers, but simultaneously opening an approach to recovery of small molecule monomers that can be used to regenerate precursors to new composite resin. To do so will require understanding of the molecular mechanism(s) of such degradation sequences. Prior work has shown the utility of hydrogen peroxide as a reagent to affect epoxy matrix decomposition [1]. Herein we describe the chemical transformations involved in that sequence: the reaction proceeds by oxygen atom transfer to the polymer's linking aniline group, forming an N-oxide intermediate. The polymer is then cleaved by an elimination and hydrolysis sequence. We find that elimination is the slower step. Scandium trichloride is an efficient catalyst for this step, reducing reaction time in homogeneous model systems and neat cured matrix blocks. The conditions can be applied to composed composite materials, from which pristine carbon fibers can be recovered.

中文翻译：

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纤维增强环氧树脂复合材料氧化降解的机理与催化。

碳纤维增强聚合物（CFRP）材料被广泛用于航空航天和娱乐设备，但是没有有效的程序来回收它们的报废。化学和工程界正在进行的工作强调通过溶解或破坏聚合物结合物从此类废物流中回收碳纤维。相比之下，我们的目标是将胺固化的环氧CFRP复合材料进行催化解聚，从而不仅能够分离高价值的碳纤维，而且同时开启了一种回收可用于将前体再生为新复合树脂的小分子单体的方法。 。为此，需要了解此类降解序列的分子机理。先前的工作表明过氧化氢作为一种试剂可以影响环氧基质的分解[1]。本文中，我们描述了该序列中涉及的化学转化：该反应通过氧原子转移至聚合物的连接苯胺基团而进行，从而形成N-氧化物中间体。然后通过消除和水解序列将聚合物裂解。我们发现消除是较慢的步骤。三氯化是该步骤的有效催化剂，可减少均相模型系统和纯净的固化基质嵌段中的反应时间。该条件可以应用于组成的复合材料，从中可以回收原始碳纤维。我们发现消除是较慢的步骤。三氯化是该步骤的有效催化剂，可减少均相模型系统和纯净的固化基质嵌段中的反应时间。该条件可以应用于组成的复合材料，从中可以回收原始碳纤维。我们发现消除是较慢的步骤。三氯化是该步骤的有效催化剂，可减少均相模型系统和纯净的固化基质嵌段中的反应时间。该条件可以应用于组成的复合材料，从中可以回收原始碳纤维。