In Situ NMR Measurement of Reactivity Ratios for the Copolymerization of 3,4-Dimethoxystyrene and <i>para</i>-Substituted Styrene
Bibliographic record
Abstract
Poly(3,4-dimethoxystyrene- co -styrene) can be used as a precursor for the synthesis of underwater adhesives. The distribution of the comonomer segments in the copolymer chain is critical to the resulting performance of the adhesives. The present study examined the reactivity ratios for the copolymerization of 3,4-dimethoxystyrene and para -substituted styrene by using the Meyer–Lowry, Mayo–Lewis, and Kelen–Tüdös methods, where in situ 1 H NMR was employed in monitoring the consumption profile of monomers. The effects of para -substitute groups, reaction temperature, and solvent on the reactivity ratios were studied. It was found that the para -substitute groups (H, methyl, and t -butyl) had little effect on the reactivity ratios for the copolymerization of 3,4-dimethoxystyrene and para -substituted styrene at 70 °C in toluene- d 8 . A lower reactivity ratio for styrene was found in the copolymerization of styrene and 3,4-dimethoxystyrene in toluene- d 8 at a lower temperature of 60 °C than that at 70 and 80 °C. Although 3,4-dimethoxystyrene showed higher reactivity ratios than styrene under all the tested conditions, a nearly random copolymerization behavior was observed for the copolymerization of styrene and 3,4-dimethoxystyrene at 70 °C in the polar solvent DMSO- d 6 . Based on the present study, it is recommended to carry out experiments covering a large range of monomer mole fraction in feed when measuring reactivity ratios regardless of the analytical methods.
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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 | 0.001 |
| 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 | 0.000 | 0.000 |
| Open science | 0.000 | 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".