Free‐Radical Propagation Kinetics of <i>N</i>‐Vinyl Formamide in Aqueous Solution Studied by PLP–SEC
Bibliographic record
Abstract
Abstract The propagation rate coefficients, kp, were determined for free‐radical polymerization of N‐vinyl formamide (NVF) in aqueous solution by pulsed‐laser‐initiated polymerization in conjunction with size‐exclusion chromatography. The polymerizations were carried out in the temperature range from 5 to 60 °C for concentrations between 3 and 100 wt.‐% NVF. A six‐fold decrease in kp was observed between polymerization of NVF in dilute aqueous solution and in bulk monomer. Intermolecular hydrogen bonding and dipolar interactions between solvent molecules and the transition state structure for NVF propagation are proposed to be responsible for these observed solvent effects, which are compared to similar effects found for the aqueous solution polymerizations of nonionized methacrylic acid and N‐vinyl pyrrolidone (NVP). Batch aqueous‐phase polymerizations of NVF and NVP demonstrate that the difference in initial rates of fractional conversion correlates with the differences in kp values for these two monomers. 2D NMR is used to study transfer reactions that occur at higher temperatures and NVF concentrations to the formic group and to the polyNVF backbone. magnified image
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How this classification was reachedexpand
Full frame machine prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. The Gemma side is a direct model label for every work in the frame, read from the title-only record. The Codex side is a classifier learned from the 10,348 direct Codex labels and calibrated to design-weighted sample rates; fields without enough sample support carry no Codex call. Candidate is the union of the two sides; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels.
Distilled classifier scores by category (both heads)
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.001 | 0.001 |
| Meta-epidemiology (narrow) | 0.001 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.000 | 0.000 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.000 | 0.001 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.001 |
| 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 source (direct Gemma or distilled Codex), 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".