Rheological properties of blends of linear and long‐chain branched polypropylenes
Bibliographic record
Abstract
Abstract Blends of a long‐chain branched polypropylene (LCB‐PP) and a linear polypropylene (L‐PP) were prepared using a twin‐screw extruder. Linear viscoelastic properties such as complex viscosity, storage modulus, and weighted relaxation spectrum were determined as functions of LCB‐PP content. Shear data obtained from commercial rheometers as well as from a slit‐die rheometer were used to verify the Cox‐Merz relation for the neat components as well as for a blend. Elongational properties were obtained using a Sentmanat Extensional Rheometer (SER) unit mounted on an Advanced Rheometric Expansion System (ARES) rheometer and the converging die. A significant strain hardening was observed for the neat LCB‐PP as well as for all the blends, but the strain hardening decreased with increasing strain rate. The apparent steady elongational viscosity values evaluated using the converging die were observed to be comparable at high deformation rates to those obtained from the SER unit, but the differences increased as the strain rate decreased. POLYM. ENG. SCI., 2010. © 2009 Society of Plastics Engineers
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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 | 0.000 | 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".