Synthesis of methacrylate macromonomers using silica gel supported atom transfer radical polymerization
Bibliographic record
Abstract
A silica gel supported CuBr-hexamethyltriethylenetetramine (HMTETA) (SG-CuBr/HMTETA) catalyst system was developed for the synthesis of poly-(methyl methacrylate) (PMMA) and poly(dimethylaminoethyl methacrylate) (polyDMAEMA) macromonomers with terminal vinyl or allyl group by atom transfer radical polymerization (ATRP). Catalyzed by SG-CuBr/HMTETA and with vinyloxyethyl 2-bromoisobutyrate (VBIB) or allyl 2-bromoisobutyrate (ABIB) as initiator, the MMA polymerization showed first order kinetics up to a 60% monomer conversion. The polymerization rate slowed down at higher conversions due to a reduction in radical concentration. Gel permeation chromatography (GPC) results showed that the decrease in radical concentration was caused by the reaction of radicals with the initiator's vinyl or allyl group moieties. In contrast, the DMAEMA polymerization was first order kinetics throughout the polymerization. The molecular weights of the resulting PMMA and polyDMAEMA increased linearly with conversion with low polydispersities. After the first run polymerization, the catalysts were recycled for second and third runs. The recycled catalysts still mediated a living polymerization of MMA or DMAEMA, producing polymers with controlled molecular weight and narrow polydispersity, but their catalytic activities decreased significantly. The reactivity reduction of the recycled catalyst was due to radical side reactions that yielded an extra amount of CuBr2 as well as the catalyst loss during recycling.
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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) | 0.000 | 0.000 |
| Bibliometrics | 0.000 | 0.000 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.003 | 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".