Syntheses and characterization of physically crosslinked hydrogels from dithiocarbamate‐derived polyurethane macroiniferter
Bibliographic record
Abstract
Abstract A dithiocarbamate (DC)‐based polyurethane macroiniferter (PUMI) was synthesized and used to prepare physically crosslinked polyurethane‐ block ‐poly (acrylamide) (PU‐ b ‐PAAm) and polyurethane‐ block ‐poly(vinyl pyrrolidone) (PU‐ b ‐PVP) hydrogels. The success of the reactions has been confirmed by FTIR, 1 H‐NMR, and 13 C‐NMR Spectroscopy analyses. The number average molecular weight of the block copolymers increased linearly with conversion and copolymerization time and thus followed a “living” radical mechanism. The water transport behavior of these polyurethane‐based hydrogels such as water uptake rate, equilibrium water content (EWC), transport number ( n ), characteristic diffusion rate constant ( K ), diffusion coefficient ( D ), and pH effect on EWC has been investigated. The results revealed that PU‐ b ‐PAAm hydrogels followed Fickian diffusion suggesting diffusion controlled swelling kinetics, whereas the PU‐ b ‐PVP hydrogels followed non‐Fickian diffusion indicating that both diffusion and structural relaxation controlled the water transport. The PU‐ b ‐PAAm hydrogels showed higher swelling at both low and high pH than at a neutral pH. This is attributed to protonation of the tertiary amines of N,N ′‐diethyl‐ N,N ′‐bis(2‐hydroxyethyl) thiuram disulfide (DHTD) at low pH and base hydrolysis of amide segments at high pH. In the thermogravimetric analysis; PUMI, PU‐ b ‐PVP and PU‐ b ‐PAAm have degraded in three distinct stages related to CS 2 evolution, hard segment degradation, and soft segment degradation. © 2008 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 46: 6272–6284, 2008
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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 | 0.000 | 0.000 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.001 | 0.000 |
| Bibliometrics | 0.000 | 0.000 |
| Science and technology studies | 0.000 | 0.002 |
| Scholarly communication | 0.000 | 0.001 |
| Open science | 0.001 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.001 | 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".