Continuous solution copolymerization of ethylene with propylene using a constrained geometry catalyst system
Bibliographic record
Abstract
Ethylene (E)/propylene (P) continuous solution copolymerization using the constrained geometry catalyst system, [CpMe4(SiMe2NtBu)]TiMe2 (CGC)/tris(pentafluorophenyl)boron/modified methylaluminoxane, was carried out at 3.45×103 kPa and 130, 140, and 150°C. Ethylene and propylene copolymers with a broad range of composition fractions were synthesized and characterized. The incorporation of propylene lowered the catalyst activity and increased chain termination reactions. The estimated reactivity ratios rE and rP were 2.89 and 0.324 at 130°C, 4.33 and 0.377 at 140°C, and 6.36 and 0.436 at 150°C, respectively. The relatively low rE and high rP values of CGC compared to other metallocene systems indicated a ready incorporation of propylene in ethylene/propylene copolymerization. The activation energies ΔEE and ΔEP were 56 and 21 kJ/mol, showing a more significant effect of polymerization temperature on rE than on rP. The reactivity ratios for normal propylene, inverted propylene, and ethylene were also estimated from the methylene sequence distributions.
Fetched live from OpenAlex and de-inverted. Abstracts are not stored in this database: the inverted indexes are 8.6 GB of the frame’s 9.3 GB of text, and the host has 13 GB free.
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) | 0.002 | 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".