Ethylene Homopolymerization Kinetics with a Constrained Geometry Catalyst in a Solution Reactor
Bibliographic record
Abstract
The solution polymerization of ethylene was studied in a semibatch reactor using a constrained geometry catalyst (CGC) and methylaluminumoxane (MAO). The influence of ethylene concentration, temperature, MAO, and catalyst concentrations on ethylene polymerization kinetics was investigated systematically. The deactivation of the CGC/MAO system during ethylene polymerization was described with a first order thermal deactivation mechanism that included reversible activation and deactivation with MAO. Interestingly, the polymerization order with respect to ethylene varied with ethylene concentration from first to second order. The trigger mechanism was shown to describe well the effect of ethylene concentration on polymer yield and polymerization kinetics. Low MAO concentration favored formation of polymer chains with unsaturated chain ends that in turn led to the production of polymers with higher long chain branch densities. It was also observed that CGC did not behave as a true single site catalyst at low MAO concentrations.
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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) | 0.003 | 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".