Insights into the Phase Structure and Dynamics of Polyurethane Rubber Using T1-T2* Relaxation Correlation
Bibliographic record
Abstract
Nuclear magnetic resonance (NMR) is a non-destructive technique that can reveal the phase structure and dynamics of polymers at the molecular level. It is sensitive to polymer chain mobility and requires minimal special sample preparation. We investigated the phase structure and molecular dynamics of polyurethane rubber (PUR) based on the T1-T2* relaxation correlation spectra, and analyzed the T1-T2* data by multi modal decay. The T1-T2* spectra showed three types of signals: rigid 1H with the shortest T2* value, interphase 1H with an intermediate T2* value, and mobile-amorphous 1H with the longest T2* value. The three 1H components exhibit the similar T1 values in PUR, which decreased with increasing hardness or decreasing temperature. The integrals of these signals depend on the durometer hardness and temperature for PUR. They increase for the rigid phase but reduce for mobile-amorphous phase and interphase with an increase of PUR durometer hardness. The rigid 1H component decreased and the mobile-amorphous 1H component increased with increasing temperature, while the interphase 1H component remained constant. In addition, the hard/soft ratio decreased with increasing temperature for PUR systems. These results indicated that T1-T2* spectra can be used to characterize phase structure and dynamics of PUR.
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How this classification was reachedexpand
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 | 0.000 | 0.000 |
| Scholarly communication | 0.001 | 0.001 |
| Open science | 0.001 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.001 | 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 itClassification
machine, unvalidatedMachine predicted; a candidate call from one teacher head, not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".