Molecular Weight Distribution of Ethylene/1‐Olefin Copolymers: Generalized Bimodality Criterion
Bibliographic record
Abstract
Two single‐site‐type metallocene catalysts can be combined to produce polymers with well‐controlled and broad molecular weight distributions (MWD). As polyolefins with unimodal and bimodal MWDs have different mechanical and rheological properties, a criterion to determine whether a system of two single‐site‐type catalysts produces polymers with unimodal or bimodal distributions is useful for product development and property optimization. In this work, a generalized MWD bimodality criterion is developed and represented as a comprehensive 3D map. The proposed criterion is validated with both simulated and previously reported experimental data. The effect of number average chain length and mass fraction on MWD bimodality criteria are also examined. The results show that unimodal MWDs are more likely to be observed when the mass fraction of one of the copolymers is much higher than the other and when both copolymers have similar average chain lengths. image
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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) | 0.001 | 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 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".