Structural Analysis of Ethylene/Propylene Copolymers Synthesized with a Constrained Geometry Catalyst
Bibliographic record
Abstract
The chain structures of five ethylene/propylene copolymer samples with propylene mole fractions of 0.277, 0.308, 0.321, 0.583, and 0.587 were analyzed and reported in this paper. These polymers were synthesized in a solution continuous stirred-tank reactor (CSTR) at 130−150 °C using a constrained geometry catalyst (CGC). The copolymers had polydispersities close to 2. Inverted propylene units were present. A large number of long runs of polyethylene and polypropylene units were also observed. Increasing the propylene composition significantly increased the sequences of one and two methylene units and decreased those of six and more consecutive methylene units. However, the uninterrupted methylene sequence distributions were little influenced by polymerization temperature. The meso and racemic contents in the continuous and inverted propylene units were approximately equal, indicating that the CGC did not have much control over the stereoregularity of the propylene insertion. Compared to the vanadium ethylene propylene elastomers (EPM), the CGC EP copolymers had fewer alternating comonomer sequences and more consecutive ethylene and propylene units.
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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) | 0.001 | 0.000 |
| Bibliometrics | 0.000 | 0.002 |
| 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) | 0.122 | 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".