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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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Conformational bias in density functional theory ring strain energy calculations of cyclopentene derivatives: Towards predictive design of chemically recyclable elastomers
Abstract Equilibrium ring opening metathesis polymerization of low strained cycloolefins is opportunistic for the development of novel materials capable of chemical recycling to monomer (CRM). However, many of the potential materials for CRM contain complex side chains complicating predictions of their ring strain energies (RSE). The effects of different conformational considerations on RSE predictions using density functional theory (DFT) are explored. New homodesmotic equations are investigated to capture changes in olefin conformation upon polymerization. The employment ofcis‐2‐butene as a corrective factor with a 2,7‐nonadiene linear analog bearing onecisand onetransolefin (H2cis) resulted in RSEs similar to previously reported ΔHpvalues. Different consideration of possible conformers aside from their lowest energy counterparts leads to a range of predicted RSE values. Similarly, the application of a Boltzmann distribution resulted in negligible differences in RSE. Therefore, RSE predictions using the lowest energy structures with H2ciscalculated at B3LYP/6‐31+G* in toluene is a sufficient approach for predicting RSE of monomers with multiple conformers. This method can be used to screen a monomer's potential for CRM to reduce the time, cost, waste, and effort necessary to research new materials towards a more circular polymer economy.
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- Award ID(s):
- 1750852
- PAR ID:
- 10385823
- Publisher / Repository:
- Wiley Blackwell (John Wiley & Sons)
- Date Published:
- Journal Name:
- Journal of Polymer Science
- Volume:
- 60
- Issue:
- 24
- ISSN:
- 2642-4150
- Format(s):
- Medium: X Size: p. 3391-3403
- Size(s):
- p. 3391-3403
- Sponsoring Org:
- National Science Foundation
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