Bibliographic record
Abstract
A new grafting-from procedure was developed for the synthesis of arborescent styrene polymers of successive generations in a single reaction pot. Styrene was first copolymerized anionically in a semibatch process with 1,3-diisopropenylbenzene (DIB), and the chains were terminated with methanol. The pendent isopropenyl moieties of the DIB units were then reacted with sec -butyllithium to generate a polyfunctional anionic macroinitiator. Further additions of styrene−DIB monomer mixture to the activated linear substrate yielded a comb-branched (generation G0) copolymer. After termination of the chain ends and activation of the double bonds on the G0 substrate, styrene monomer was added to generate G1 arborescent polystyrenes, with a dendritic architecture. Alternately, the G0 copolymer was isolated by precipitation and activated in a separate procedure. The size (molecular weight) of the side chains in the G1 polymer was conveniently controlled by varying the amount of monomer added to the G0 macroinitiator. The reaction conditions were optimized to obtain graft polymers with relatively low polydispersity indices ( M w / M n = 1.1−1.3) and absolute weight-average molecular weights M w reaching 7 × 10 6 . The intrinsic viscosity in toluene of the arborescent G1 polystyrenes synthesized was up to 7.2 times lower than for linear polystyrene samples of comparable molecular weight.
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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 | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.001 |
| Insufficient payload (model declined to judge) | 0.003 | 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".