Synthesis of LDPE Using Pyridineimine‐Based Nickel (II) Bromide Complexes: Effect of Catalyst Bulkiness on Thermal, Structural, and Morphological Properties
Bibliographic record
Abstract
Abstract A series of pyridine‐imine [N‐N] ligands are efficiently prepared through the condensation reaction of ketone/aldehyde precursor and synthesized aniline. The ligands (L n , n = 1–4) and corresponding nickel complexes (C n , n = 1–4) are characterized and used for polymerization of ethylene in the presence of modified methylaluminoxane as cocatalyst. The produced low density polyethylenes show at least 21 branches per 1000 carbon atoms with M v values up to 80.0 × 10 4 . Aldimino‐based catalyst is more active than the analogue catalyst, although, ketimines result in polyethylene with higher M v . Nevertheless, the product of aldimino‐based catalyst indicates the highest melting point of 132.3 °C but ketimine exhibits the highest crystallinity of 32.98% at the same polymerization conditions. Specific morphologies including smooth spherical and irregular porous particles are observed for some polymer samples. However, at high polymerization temperatures and different monomer pressures, different morphologies as well as two melting point peaks are observed in scanning electron microscopy (SEM) images and differential scanning calorimeter thermograms, respectively.
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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 | 0.000 |
| 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 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".