Abstract
Conventional cross-linked polyurethane (PU) or PU networks are unable to be reprocessed in the melt state into reshaped, high-value recycled products. This is because of the irreversible nature of the cross-links in PU, a common feature of thermosets which prevents the cross-linked network or thermoset from ever returning to a melt state. We have recently discovered several chemical platforms for making cross-linked polymers melt-reprocessable by instilling a reversible nature to the cross-links as a function of temperature. Here, we describe our approach for making reprocessable polyhydroxyurethane (PHU) networks that exhibit full property recovery associated with cross-link density after multiple melt-state reprocessing steps. PHUs are a class of non-isocyanate-based polyurethanes (NIPUs) that can be synthesized via reaction of amines with cyclic carbonates; the PHUs contain urethane linkages with adjacent primary or secondary hydroxyl groups. In the presence of appropriate catalyst, we have synthesized PHU networks with robust properties at room temperature and many tens of degrees above room temperature. These networks containing appropriate catalyst can be effectively reprocessed at least three times at 140 °C leading to full recovery within error of rubbery-state plateau modulus and room-temperature tensile strength and strain at break.
Original language | English (US) |
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State | Published - 2018 |
Event | 2018 Society of Plastics Engineers Annual Technical Conference, ANTEC 2018 - Orlando, United States Duration: May 7 2018 → May 10 2018 |
Conference
Conference | 2018 Society of Plastics Engineers Annual Technical Conference, ANTEC 2018 |
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Country/Territory | United States |
City | Orlando |
Period | 5/7/18 → 5/10/18 |
ASJC Scopus subject areas
- General Chemical Engineering
- Polymers and Plastics