Degradable polymers made via ring-opening metathesis polymerization (ROMP) hold tremendous promise as eco-friendly materials. However, most of the ROMP monomers are derived from petroleum resources, which are typically considered less sustainable compared to biomass. Herein, we present a synthetic strategy to degradable polymers by harnessing alternating ROMP of biomass-based cyclic olefin monomers including exo-oxanorbornenes and cyclic enol ethers. A library of well-defined poly(enol ether)s with modular structures, tunable glass transition temperatures, and controlled molecular weights was achieved, demonstrating the versatility of this approach. Most importantly, the resulting copolymers exhibit high degrees of alternation, rendering their backbones fully degradable under acidic conditions.
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This content will become publicly available on February 28, 2025
Modular Approach to Bio-Based Poly(enol ether)s with Tunable Thermal Properties and Degradability
Biomass-derived polymer materials are emerging as sustainable and low-carbon footprint alternatives to the current petroleum-based commodity plastics. In the past decade, the ring-opening metathesis polymerization (ROMP) technique has been widely used for the polymerization of cyclic olefin monomers derived from biorenewable resources, giving rise to a diverse set of biobased polymer materials. However, most synthetic biobased polymers made by ROMP are nondegradable because of their all-carbon backbones. Herein, we present a modular synthetic strategy to acid-degradable poly(enol ether)s via ring-opening metathesis copolymerization of biorenewable oxanorbornenes and 3,4-dihydropyran (DHP). 1H NMR analysis reveals that the percentage of DHP units in the resulting copolymers gradually increases as the feed ratio of DHP to oxanorbornene increases. The composition of the copolymers plays a pivotal role in governing their thermal properties. Thermogravimetric analysis shows that an increasing percentage of DHP results in a decrease in the decomposition temperatures, suggesting that the incorporation of enol ether groups in the polymer backbone reduces the thermal stability of the copolymers. Moreover, a wide range of glass transition temperatures (16–165 °C) can be achieved by tuning the copolymer composition and the oxanorbornene structure. Critically, all of the poly(enol ether)s developed in this study are degradable under mildly acidic conditions. A higher incorporation of DHP in the copolymer leads to enhanced degradability, as evidenced by smaller final degradation products. Altogether, this study provides a facile approach for synthesizing biorenewable and degradable polymer materials with highly tunable thermal properties desired for their potential industrial applications.
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- Award ID(s):
- 2316842
- NSF-PAR ID:
- 10492870
- Publisher / Repository:
- American Chemical Society
- Date Published:
- Journal Name:
- ACS Applied Polymer Materials
- ISSN:
- 2637-6105
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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