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Abstract Chemical recycling to monomer (CRM) is a promising route for transitioning to a circular polymer economy. To develop new CRM systems with useful properties, it is important to understand the effects of monomer structure on polymerization/depolymerization behavior. In earlier work, this group demonstrated chemically recyclable polymers prepared by ring‐opening metathesis polymerization oftrans‐cyclobutane fused cyclooctenes (tCBCO). Here, it is investigated how different substituents on cyclobutane impact the thermodynamics and thermal properties oftCBCO polymers. Introducing additional substituents to acis‐diester functionalizedtCBCO is found to favor the conversion of polymerization; increased polymerization conversion is also observed when thecis‐diester is isomerized into itstranscounterpart. The effects of these structural features on the thermal properties are also studied. These findings can provide important insights into designing next‐generation CRM polymers.
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Chemically recyclable thermoplastics from reversible-deactivation polymerization of cyclic acetals
Identifying plastics capable of chemical recycling to monomer (CRM) is the foremost challenge in creating a sustainable circular plastic economy. Polyacetals are promising candidates for CRM but lack useful tensile strengths owing to the low molecular weights produced using current uncontrolled cationic ring-opening polymerization (CROP) methods. Here, we present reversible-deactivation CROP of cyclic acetals using a commercial halomethyl ether initiator and an indium(III) bromide catalyst. Using this method, we synthesize poly(1,3-dioxolane) (PDXL), which demonstrates tensile strength comparable to some commodity polyolefins. Depolymerization of PDXL using strong acid catalysts returns monomer in near-quantitative yield and even proceeds from a commodity plastic waste mixture. Our efficient polymerization method affords a tough thermoplastic that can undergo selective depolymerization to monomer.
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- Award ID(s):
- 1719875
- PAR ID:
- 10325430
- Date Published:
- Journal Name:
- Science
- Volume:
- 373
- Issue:
- 6556
- ISSN:
- 0036-8075
- Page Range / eLocation ID:
- 783 to 789
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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- Free Publicly Accessible Full Text
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Accepted Manuscript1.0
- Journal Article:
- https://doi.org/10.1126/science.abh0626
