An Wenli, Liu Xuehui, Li Junyan, Zhao Xu, Long Yuwei, Xu Shimei, Wang Yu-Zhong
The Collaborative Innovation Center for Eco-Friendly and Fire-Safety Polymeric Materials (MoE), State Key Laboratory of Polymer Materials Engineering, National Engineering Laboratory of Eco-Friendly Polymeric Materials (Sichuan), College of Chemistry, Sichuan University, Chengdu 610064, China.
The Collaborative Innovation Center for Eco-Friendly and Fire-Safety Polymeric Materials (MoE), State Key Laboratory of Polymer Materials Engineering, National Engineering Laboratory of Eco-Friendly Polymeric Materials (Sichuan), College of Chemistry, Sichuan University, Chengdu 610064, China.
J Hazard Mater. 2023 Jul 5;453:131423. doi: 10.1016/j.jhazmat.2023.131423. Epub 2023 Apr 14.
As one of the largest productions of thermosetting plastics, unsaturated polyester resin (UPR) is difficult to be effectively chemcycled after it is discarded due to its dense network structure. Herein, we demonstrate a mild method for efficient alkaline hydrolysis of UPR into useful feedstocks in mixed solvents of polar aprotic solvent and a small amount of HO by utilizing the fragmentation effect of the solvent on the UPR and the swelling effect of HO on the subsequent partially hydrolyzed UPR respectively. The mixed solvents also play a key role in the aggregation and solubility of the degradation products. It is worth noting that the tetrahydrofuran (THF)-HO system achieved 100 % separation of degradation products in an energy-efficient way taking advantage of the insolubility of the carboxylate-containing products in THF and the low boiling point of THF. The participation of non-reactive mixed solvents greatly promotes both the degradation and the separation process of thermosetting polymers.
作为热固性塑料的最大产量产品之一，不饱和聚酯树脂（UPR）由于其致密的网络结构，在被丢弃后难以进行有效的化学循环利用。在此，我们展示了一种温和的方法，通过分别利用极性非质子溶剂对UPR的碎片化作用以及水对随后部分水解的UPR的溶胀作用，在极性非质子溶剂和少量水的混合溶剂中将UPR高效碱性水解为有用的原料。混合溶剂在降解产物的聚集和溶解性方面也起着关键作用。值得注意的是，四氢呋喃（THF）-水体系利用含羧酸盐产物在THF中的不溶性以及THF的低沸点，以节能的方式实现了降解产物的100%分离。非反应性混合溶剂的参与极大地促进了热固性聚合物的降解和分离过程。
