使用高性能Sn (II) /酒精催化剂系统将商业Poly (I-乳酸) 化学回收为L-乳酸
Thomas M McGuire1, Antoine Buchard2, Charlotte Williams1
1Department of Chemistry, Chemistry Research Laboratory, University of Oxford, 12 Mansfield Road, Oxford, OX1 3TA, U.K.
Journal of the American Chemical Society
|September 1, 2023
概括
这项研究引入了一种有效的化学回收方法,用于将多乳酸 (PLLA) 废物转化为其单体,l-乳酸 (l-LA). 这种新型的催化剂系统在低温下运行,显著提高了可持续塑料回收的产量和纯度.
科学领域:
- 聚合物化学
- 绿色化学
- 材料科学
背景情况:
- 聚氨酸 (PLLA) 是一种广泛用于塑料和纤维的生物聚合物.
- 目前用于PLLA的化学回收方法耗费大量能量,并且具有较低的催化活性和诸如表皮化等副作用.
- 对于可持续的循环经济方法来说,有效地将消费后的PLLA废物脱聚化为其单体,l-乳化物 (l-LA).
研究的目的:
- 为PLLA废物开发一种高效且低温的化学回收方法.
- 研究一种用于将PLLA脱聚化为l-乳酸的新型 (II) 催化剂系统.
- 评估PLLA化学回收到单体 (CRM) 的开发系统的催化活性,选择性和可回收性.
主要方法:
- 使用商业 (II) 催化剂与商业非挥发性酒精一起使用.
- 在流或真空下,在低温 (160°C) 下进行整洁的PLLA薄膜的脱聚合.
- 在多个PLLA降解周期中研究了催化剂负载,周转频率 (TOF) 和可回收性.
主要成果:
- 通过PLLA脱聚合获得了优异的产量 (92%) 和纯度 (> 99%).
- 与以前的方法相比,基于Sn的催化剂系统表现出明显更高的活性 (高达3000×TOF) 和较低的催化剂负荷 (高达6000×低).
- 成功将废弃的PLLA塑料包装 (咖啡杯盖) 转化为纯乳酸.
- 在四个回收周期后,催化剂系统保持了高生产率和选择性.
结论:
- 开发的Sn-催化剂和酒精系统可使PLLA废物高效且低温的化学循环转化为l-乳化物.
- 这种方法为PLLA循环性提供了可持续且具有成本效益的方法,在活动和效率方面超越了现有的技术.
- 催化剂系统的可回收性进一步提高了其在PLLA废物管理中的工业应用的可行性.
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