Continuous Polymerizations in Supercritical Carbon Dioxide
Bibliographic record
Abstract
We have developed a system for the continuous polymerization of various monomers in scCO2 and the continuous removal of polymer particles from high-pressure to ambient conditions. Experiments have been performed with the surfactant-free precipitation polymerization of vinylidene fluoride (VF2) and acrylic acid (AA) utilizing diethyl peroxydicarbonate (DEPDC) as the free-radical initiator for VF2, and 2,2'-azobis(isobutyronitrile) (AIBN) as the freeradical initiator for AA. The PVDF and AA polymers were collected as dry, "free-flowing" powders. Tunable bimodal molecular weight distributions (MWDs) of poly(vinylidene fluoride) (PVDF) were achieved by varying the VF2 concentration. The conversion of VF2 in these polymerizations ranged from 7 to 26%, and the rate of polymerization (Rp) reached a maximum of 27 x 10-5 mol/L-s at a VF2 feed monomer concentration of 2.5 mol/L at 75 °C. Homogeneous freeradical kinetics provided a good approximation for the rate of polymerization (Rp) of this heterogeneous polymerization. The PVDF material was characterized by gel permeation chromatography (GPC) and melt flow index (MFI) giving Mw's up to 104 kg/mol, and MFI's as low as 3.0 at 230 °C.
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How this classification was reachedexpand
Full frame distilled prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. Learned from the 10,348 direct Codex labels and 10,348 direct Gemma labels. Candidate is the union of thresholded teacher heads; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels or direct frontier model labels.
Codex and Gemma teacher scores by category
| 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) | 0.000 | 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 teacher head, 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".