Cleavable Additives for Deconstructable, Recyclable Polyurethane Thermosets
Why this work is in the frame
A frame that forgets how it found something cannot be audited. These are the routes that admitted this work.
Bibliographic record
Abstract
Polyurethane (PU) thermosets, particularly those derived from aliphatic components, are challenging to chemically deconstruct due to their permanent cross-linking. Current approaches to impart deconstructability typically rely on complete substitution of network precursors with cleavable analogs, limiting practicality. Cleavable additives (CAs) offer a potentially simple and cost-effective alternative, yet their application has been largely confined to chain-growth networks and remains unexplored in end-linked systems such as PUs. Here, we present a generalizable reverse gel-point theory that predicts the minimum CA loading required for deconstruction of end-linked networks. We validate this framework experimentally through the incorporation of two classes of silyl ether-based CAsbifunctional cleavable strands (BCSs) and trifunctional cleavable junctions (TCJs)into PU thermosets. Both additives enable selective PU dissolution at low loadings (5-12 wt %), with TCJs demonstrating enhanced efficiency. The combined use of BCSs and TCJs also allows fine-tuning of material properties. Furthermore, we show that polyol fragments generated from the deconstruction of TCJ-containing PUs can be chemically repolymerized to regenerate PU materials without loss of mechanical performance over multiple cycles. This work establishes CAs as a viable strategy for advancing PU circularity and offers a foundational framework for their broader application in end-linked polymer networks.
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Full frame distilled prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. Learned from the 10,348 direct Codex labels and 10,348 direct Gemma labels. Candidate is the union of thresholded teacher heads; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels or direct frontier model labels.
Codex and Gemma teacher scores by category
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.001 | 0.000 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.000 | 0.001 |
| Science and technology studies | 0.001 | 0.001 |
| Scholarly communication | 0.000 | 0.001 |
| Open science | 0.001 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.000 | 0.000 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from it