Radical Copolymerization of Vinylidene Fluoride (VDF) with Oligo(hexafluoropropylene oxide) Perfluorovinyl Ether Macromonomer To Obtain PVDF-<i>g</i>-oligo(HFPO) Graft Copolymers
Bibliographic record
Abstract
The synthesis of PVDF- g -oligo(HFPO) graft copolymers, where VDF and HFPO stand for vinylidene fluoride and hexafluoropropylene oxide, respectively, is presented. First, an oligo(HFPO)–OCF═CF 2 macromonomer was prepared from two methods starting from oligo(HFPO) acyl fluoride in 34 to 54% yield. Then, the radical copolymerization of VDF with that comonomer, initiated by tert -butyl peroxypivalate (TBPPi) or perfluoro-3-ethyl-2,4-dimethyl-3-pentyl persistent radical (PPFR) was studied under various conditions. The resulting PVDF- g -oligo(HFPO) graft copolymers were produced in good isolated yields (74 to 89%). The molar percentages and molecular weights of the graft copolymers were assessed by 19 F and 1 H NMR spectroscopy. Molar percentages of VDF and oligo(HFPO)–OCF═CF 2 comonomers reached up to 99% and 11%, respectively, while the molecular weights ranged from 25 000 to 77 000 g/mol. Their thermal properties were also studied and showed: (1) satisfactory thermostability ( T d ) in the 410 to 494 °C range under air and (2) melting temperature ( T m ) between 138 to 159 °C, while (3) the glass transition ( T g ) ranged from −79 to −54 °C.
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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".