Epoxy thermoset materials are widely used in the field of electrical engineering, including gas-insulated enclosed switches and drytype transformers. It is a challenge to degrade and recycle traditional epoxy thermosets, which can lead to serious resource wastage and solid waste pollution. Previously reported strategies have often required harsh chemical conditions or complex chemical syntheses, which cannot effectively recycle and degrade the large amount of existing anhydride-cured epoxy thermoset waste used in electrical engineering. Herein, we propose an efficient and economical degradation strategy for epoxy thermosets based on a commercial transesterification catalyst (1,8-diazabicyclo[5.4.0]undec-7-ene, DBU). DBU is much cheaper than the widely reported transesterification catalyst in the field of degrading and recycling epoxy thermosets (1,5,7-triazabicyclo[4.4.0]dec-5-ene, TBD). We demonstrated that an anhydride-cured epoxy thermoset could be completely depolymerized in DBU-ethylene glycol solution below 140 °C in 2 h (or 120 °C in 3 h). Our study offers an effective method to recycle anhydride-cured epoxy thermoset wastes.

中文翻译：

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一种基于低成本酯交换催化剂的高效、经济的环氧树脂热固性塑料降解策略


环氧热固性材料广泛用于电气工程领域，包括气体绝缘封闭开关和干式变压器。降解和回收传统环氧树脂热固性材料是一项挑战，这可能导致严重的资源浪费和固体废物污染。以前报道的策略通常需要苛刻的化学条件或复杂的化学合成，这无法有效地回收和降解电气工程中使用的大量现有酸酐固化环氧树脂热固性废物。在此，我们提出了一种基于商业酯交换催化剂（1,8-二氮杂双环[5.4.0]十一碳-7-烯，DBU）的高效且经济的环氧热固性塑料降解策略。在降解和回收环氧树脂热固性塑料（1,5,7-三氮杂双环[4.4.0]dec-5-ene，TBD）领域，DBU 比广泛报道的酯交换催化剂便宜得多。我们证明，酸酐固化的环氧树脂热固性树脂可以在 2 小时内（或 3 小时内在 120 °C）的 DBU-乙二醇溶液中完全解聚。我们的研究提供了一种回收酸酐固化的环氧树脂热固性废物的有效方法。