化学可回收聚乙烯的可裂变共体:对乙烯聚合物循环性的一般方法
Gavin R Kiel1, David J Lundberg2, Elisabeth Prince1
1Department of Chemistry, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, Massachusetts 02139, United States.
Journal of the American Chemical Society
|June 28, 2022
概括
新的提奥诺拉克添加剂可以化学回收聚乙烯等聚烯. 这一过程允许去聚合和再聚合,产生与原材料相似的可回收塑料.
科学领域:
- 聚合物化学
- 材料科学
- 可持续的化学
背景情况:
- 乙烯基聚合物,如聚乙烯,是普遍存在的,但由于它们的环境持久性,造成了回收挑战.
- 目前的回收方法往往会降低材料的性能,限制真正的循环性.
- 将可分割的单元纳入聚合物骨干提供了提高可回收性的潜在途径.
研究的目的:
- 开发和评估作为可裂变的共聚物添加剂用于乙烯聚合.
- 通过使用这些添加剂来证明乙烯基聚合物的化学分解和回收.
- 研究所产生的聚合物的特性和可回收性.
主要方法:
- 在聚烯 (PS) 和其它乙烯聚合物中结合诺共聚物的自由基聚合.
- 改性聚合物的选择性化学脱聚合.
- 脱聚合碎片的氧化再聚合.
- 聚合物分子质量,性能和回收效率的表征.
主要成果:
- 统计学上结合的乙烯链接 (2.555mol%) 使PS可选择性去聚合到乙烯末端碎片 (<10kDa).
- 通过氧化再聚合生成的回收PS获得了高产量 (8095%) 和与原始材料几乎相同的摩尔质量,证明了摩尔质量记忆效应.
- 具有2.5%摩尔连接的可拆解PS及其回收对应物表现出与原始PS可比的热力学性能.
- 这种方法对于交联的烯共聚物和多烯酸盐是有效的.
结论:
- 乙烯基聚合物的化学解构和循环利用中,烯酸作为有效的可裂变共聚物添加剂.
- 这种方法有助于制造具有保留性质的可回收聚合物,为增强聚合物循环性提供了总体策略.
- 证明的摩尔质量记忆效应和性质保留表明了可持续的聚合物管理的可行途径.
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