The effect of ligand molecular weight on copper salt catalyzed oxidative coupling polymerization of 2,6‐dimethylphenol
Bibliographic record
Abstract
Abstract Polyphenylene oxide (PPO) was prepared via oxidative coupling polymerization of 2,6‐dimethylphenol (DMP) catalyzed by copper salt. The ligand was a novel series of random copolymers (PSVP) of styrene and 4‐vinylpyridine prepared by reversible addition‐fragmentation chain transfer (RAFT) copolymerization. The copolymers with well‐controlled molecular weight (MW) were used to study the effects of ligand molecular weight on the catalytic activity and selectivity. It was found that the catalytic activity increased with the molecular weight but there existed an upper MW limit above which no further increase in activity could be achieved. With PSVP of F vPy = 0.39, the critical MW was about 5000 g/mol. The mechanism involved in the successive complexation of copper ions and PSVP was elucidated and the equilibrium constants were estimated by pH titration. It was found that the macromolecular ligand was in favor of bridging Cu II ions that formed catalytically active dinuclear copper‐amine complexes. However, the catalytic selectivity was almost independent of the ligand MW. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010
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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 | 0.000 |
| Science and technology studies | 0.000 | 0.001 |
| Scholarly communication | 0.000 | 0.000 |
| 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 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".