High-Temperature Free Radical Copolymerization of Styrene and Butyl Methacrylate with Depropagation and Penultimate Kinetic Effects
Bibliographic record
Abstract
Copolymers of methacrylate and styrene, the main components of many solvent-based automotive coating formulations, are produced under higher temperature starved-feed conditions in order to reduce the solvent level while controlling polymer composition. Under these conditions methacrylate depropagation has a significant impact on polymer molecular weights and free monomer concentrations in the reactor. Meanwhile, a strong penultimate effect has been observed for this binary system at lower temperatures, also affecting the polymerization rate. In this work, the combined effect of depropagation and penultimate copolymerization kinetics is investigated. The copolymer-averaged propagation rate coefficient for butyl methacrylate and styrene is determined as a function of monomer composition using pulsed-laser polymerization over a range of temperatures. A clear penultimate effect is seen even at the elevated temperatures at which depropagation is important. Radical and monomer reactivity ratios show a negligible temperature dependency between 50 and 150 °C. The Lowry case 1 representation adequately describes the effect of methacrylate depropagation over the range of conditions examined.
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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 | 0.000 |
| 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".