Arborescent Polystyrene-<i>g</i><i>raft</i>-poly(2-vinylpyridine) Copolymers: Synthesis and Enhanced Polyelectrolyte Effect in Solution
Bibliographic record
Abstract
A technique is described for the preparation of arborescent copolymers containing poly(2-vinylpyridine) (P2VP) segments. 2-Vinylpyridine is first polymerized with 1,1-diphenyl-2-methylpentyllithium in tetrahydrofuran in the presence of N, N, N ‘, N ‘ -tetramethylethylenediamine (TMEDA). The graft copolymers are obtained by titration of the P2VP anions with a solution of a chloromethylated polystyrene substrate. Copolymers incorporating either short ( M w ≈ 5000) or long ( M w ≈ 30 000) P2VP side chains were prepared by grafting onto linear, comb-branched (G0), G1, and G2 chloromethylated arborescent polystyrenes. Branching functionalities ranging from 14 to 3880 and molecular weights ranging from 8.2 × 10 4 to 6.7 × 10 7 were obtained for the copolymers, while maintaining a low apparent polydispersity ( M w / M n ≈ 1.06−1.15) after grafting. Characterization data for these materials from size exclusion chromatography and light scattering indicate that they have a highly compact structure. Dynamic light scattering results show that the arborescent poly(2-vinylpyridine) copolymers expand much more in solution than the linear homologous polymers when protonated with HCl. This is attributed to the higher charge density attained in the branched copolymers.
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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".