New epoxide initiators for the controlled synthesis of functionalized polyisobutylenes
Bibliographic record
Abstract
The mechanism of initiation was investigated in isobutylene (IB) polymerizations initiated by epoxidized α-methylstyrene (MSE) and 1,2-epoxy-2,4,4-trimethylpentane (TMPO) in conjunction with TiCl4. The proposed mechanism predicts primary OH head groups and tertiary Cl end groups in the PIB. Model studies conducted with MSE/TiCl4 and diisobutylene lead to ring closure yielding a substituted furanyl structure. Real-time fiber-optic refractive index monitoring was used to follow the initiation with the TMPO/TiCl4 system. It was found that the cleavage of TMPO proceeds simultaneously by SN1 and SN2 mechanisms as proposed. The carbocation forming by the SN1 route is proposed to initiate the polymerization of IB, but it was shown that excess TiCl4 relative to TMPO was necessary for propagation. Isomerization and polyether formation by the SN2 pathway lead to side reactions, reducing the initiating efficiency.
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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) | 0.000 | 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 | 0.001 |
| 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".