Alternate Co-Catalysts For Ziegler-Natta High Temperature Olefin Polymerization
Bibliographic record
Abstract
Typically a Ziegler-Natta catalyst formulation includes the use of alkyl aluminum compounds and this investigation involves the substitution of triethyl aluminum (TEAL) with n-BuLi. It was found that this lithium compound, used as first co-activator, produced polyethylene at rates high enough for solution polymerization technology. Catalyst activity and molecular weight data were collected from a lab-scale continuous polymerization reactor at 150, 170 and 190oC. A balance between n-BuLi and a second alkyl aluminum compound (AA-2), used as second co-activator in the catalyst formulation, enabled the catalyst to achieve a performance (catalyst activity and polymer molecular weight) similar to that obtained with TEAL. It is proposed that the optimum balance between these two compounds is related to the difference in the reducing power of n-BuLi and AA-2, and one of the chain transfer reactions is to AA-2.
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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 | 0.001 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.001 | 0.000 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.001 | 0.001 |
| Open science | 0.001 | 0.000 |
| Research integrity | 0.000 | 0.001 |
| Insufficient payload (model declined to judge) | 0.001 | 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".