Switchable Polyolefins from Polar Functionalization to Degradability  

作　　者：Kangkang Li Zhongbao Jian 

机构地区：[1]State Key Laboratory of Polymer Physics and Chemistry,Changchun Institute of Applied Chemistry,Chinese Academy of Sciences,Changchun 130022 [2]School of Applied Chemistry and Engineering,University of Science and Technology of China,Hefei 230026

出　　处：《CCS Chemistry》2024年第8期1941-1950,共10页中国化学会会刊（英文）

基　　金：the National Natural Science Foundation of China(grant no.22122110);the Jilin Provincial Science and Technology Department Program(grant no.20230101347JC).

摘　　要：Polyolefins are synthetic plastics that exist on the largest scale and are ubiquitous in human life.They are also the most frequently discarded plastics.Consequently,the ability to either upgrade polyethylene(PE)plastic for value-added applications or to degrade PE plastic for value-added chemicals and monomers is highly desirable and sought after to mitigate the plastic waste problem.Herein,we report an advanced strategy for tackling the issue of PE plastics,first through a sequential upgrading and then through a degrading pathway.The optimal Diels–Alder-type polar comonomer diester-substituted norbornadiene is copolymerized with ethylene to produce the desired polar-functionalized PEs with both high comonomer incorporations of 42.4 mol%(-COOMe:as high to 59.6 mol%)and high molecular weights of up to 224 kg mol^(−1)in high catalytic activities of>100 kg mol^(−1)h^(−1).By means of a decisive retro-Diels–Alder reaction,this upgraded PE,namely polar-functionalized PE,can completely switch to a clean and soluble vinylene PE with a high content(28.7 mol%)of dispersed internal double bonds,which are degradable.Ethenolysis of the highmolecular–weight(∼30 kg mol^(−1))vinylene PE with ethylene yields industrially relevant telechelic oligomers(∼360 g mol^(−1))of long-chainα,ω-dienes and C9/C9+hydrocarbon products.This chemical upgrading and recycling method makes polyolefin plastic more sustainable.

关 键 词：chemical recycling plastics polar polyolefin degradable polyolefin cyclic olefin 

分 类 号：O64[理学—物理化学]