Effect of Recycling on the Rheological Properties and Foaming Behaviors of Branched Polypropylene
Bibliographic record
Abstract
The effects of recycling of branched polypropylenes on their rheological properties and foamability are studied in this paper. The rheological properties and foamability of branched polypropylene are compared with those of the virgin sample. The main purpose of the study was to explore the possibility of using recycled materials to make the acceptable foam products. The recycled polypropylenes showed the lower melt strength due to the lowered molecular weight and disentanglement of molecules. However, the high-shear viscosities of the virgin and recycled resins exhibited almost the same values whereas the zero-shear rate viscosity was lower for recycled ones. The rheological behavior of the resins was correlated to the foaming behavior. It was observed that the contribution of the storage modulus (G’) was more pronounced than the loss modulus (G”). The foam morphology of recycled branched polypropylene and the virgin material was studied at various processing temperatures using a single-screw tandem foam extrusion system. The volume expansion ratio and cell population density results were correlated with the rheological data. Despite the noticeable drop in the melt strength, it was found that the foamability did not significantly deteriorate by recycling.
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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 | 0.001 | 0.002 |
| Meta-epidemiology (narrow) | 0.001 | 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 | 0.001 |
| 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".