Modeling of Branching and Gelation in RAFT Copolymerization of Vinyl/Divinyl Systems
Bibliographic record
Abstract
The reversible addition−fragmentation chain transfer radical polymerization (RAFT) with branching/cross-linking is theoretically investigated on the basis of the method of moments. The system considered consists of the copolymerization of vinyl monomer in the presence of a small amount of divinyl comonomer. It is found that the gel point is significantly postponed by increasing the RAFT agent concentration. Flory’s criterion, ρ r w,0 = 1, is found to be satisfied at the gel point in the RAFT cross-linking process regardless of the unequal reactivities of vinyl/divinyl monomers in the absence of cyclization. The gel conversion can be analytically expressed and is determined by the polymerization recipe and the relative reactivities of various double bonds. The gel point is postponed by the presence of intramolecular cyclization, and its effect becomes significant in a dilute polymerization system. Branching distribution is found to be very broad with a large fraction of linear primary and slightly branched chains. By the introduction of the dependence of the reactivity of the pendant double bond on the local heterogeneity, the branching distribution becomes narrower and can be fine-tuned.
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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 | 0.001 |
| Open science | 0.001 | 0.000 |
| Research integrity | 0.001 | 0.000 |
| Insufficient payload (model declined to judge) | 0.001 | 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 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".