Hydrolysis of Polyamide 6 to ε-Caprolactam over Titanium Dioxide.

IF 6.6 2区 化学 Q1 CHEMISTRY, MULTIDISCIPLINARY
ChemSusChem Pub Date : 2025-09-23 DOI:10.1002/cssc.202501186
Pedro Moura, Weiqing Zheng, Esun Selvam, Dionisios G Vlachos
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引用次数: 0

Abstract

Polyamides (PAs) are an important component of discarded textiles and food packaging. Chemical recycling can recover PA monomers, enabling repolymerization to produce virgin-grade PA. However, contemporary PA chemical recycling methods employ homogeneous catalysts that are hard to separate. Anatase TiO2 is reported as a catalyst for PA6 hydrolysis at 270 °C for 0.5 h, achieving a maximum ε-caprolactam (CL) yield of 81% (limited by thermodynamic equilibrium). The CL yield decreases upon catalyst reuse, due to loss of catalyst surface area induced by significant changes in catalyst crystallinity and texture. Pretreating the catalyst hydrothermally stabilizes it against morphological changes, yielding repeatable CL yields. Overall, this study discloses a heterogeneous catalyst capable of producing repeatable equilibrium CL yields via PA6 hydrolysis under industrially relevant reaction temperatures and times (<3 h, 250-330 °C).

聚酰胺6在二氧化钛上水解制备ε-己内酰胺。
聚酰胺(PAs)是废弃纺织品和食品包装的重要成分。化学回收可以回收PA单体,使再聚合生产出初级PA。然而,当代PA化学回收方法采用难以分离的均相催化剂。据报道,锐钛矿TiO2在270℃下水解PA6 0.5 h,最大ε-己内酰胺(CL)产率为81%(受热力学平衡限制)。由于催化剂结晶度和结构的显著变化导致催化剂表面积的损失,重复使用催化剂后CL产率降低。对催化剂进行水热预处理,使其不受形态变化的影响,从而产生可重复的CL产率。总的来说,本研究揭示了一种多相催化剂,能够在工业相关的反应温度和时间下通过PA6水解产生可重复的平衡CL产率(
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来源期刊
ChemSusChem
ChemSusChem 化学-化学综合
CiteScore
15.80
自引率
4.80%
发文量
555
审稿时长
1.8 months
期刊介绍: ChemSusChem Impact Factor (2016): 7.226 Scope: Interdisciplinary journal Focuses on research at the interface of chemistry and sustainability Features the best research on sustainability and energy Areas Covered: Chemistry Materials Science Chemical Engineering Biotechnology
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