A Capping Method for Nitrogen Anion Initiated Living Anionic Polymerization for Synthesizing Alkyl Methacrylate Macromonomers
Bibliographic record
Abstract
Lithium alkylamides are important functional initiators for anionic polymerization of methacrylates, but only sterically hindered ones can initiate a successful living polymerization. A capping method is reported here to modify nitrogen anion initiators (capping reaction) for living anionic polymerization of alkyl methacrylates. Dimethylacrylamide (DMA) and tert -butyl methacrylate ( t BMA) were found to be effective capping agents for lithium diallylamide. After capped with DMA or t BMA, the initiator efficiency of lithium diallylamide was increased from 0.1 to 0.9 for various monomers. Monosubstituted lithium alkylamides (vinyloxypropylamide and allylamide) could not directly initiate the polymerization of methacrylates due to severe reaction with the carbonyl groups in the monomers. After capped with DMA, the initiators polymerized methacrylates with initiator efficiency about 0.4−0.6, depending on the monomer type. t BMA was not suitable as capping agent for the monosubstituted lithium amides. Using these capped initiators, we subsequently synthesized block copolymers. 1 H NMR demonstrated that all the polymers prepared had terminal unsaturated groups from the initiators.
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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 | 0.000 | 0.000 |
| 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 | 0.000 |
| Open science | 0.001 | 0.000 |
| Research integrity | 0.000 | 0.001 |
| Insufficient payload (model declined to judge) | 0.001 | 0.001 |
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".