Impact of mechanical reprocessing on degradation and performance of PA 11 and PA 11–LDPE blends
Bibliographic record
Abstract
This study examines the mechanical recycling of a virgin PA 11 and a post-consumer PA 11–low density polyethylene (LDPE) (90/10) blend over ten reprocessing cycles. Fourier transform infrared spectroscopy (FTIR) and proton nuclear magnetic resonance (¹H NMR) analyses revealed changes in the intensity and position of specific absorption bands and proton signals, indicating progressive chain scission and molecular rearrangements. A carbonyl band was identified in the virgin PA 11 after reprocessing, a confirmation of thermo-oxidative degradation. Mechanical testing showed gradual reductions in elastic modulus, stress at break, and impact strength, with significant deterioration from the third cycle onward. Rheological analysis revealed consistent decreases in storage modulus ( G′ ), loss modulus ( G″ ), complex viscosity ( η* ), and changes in damping factor (tan δ ), reflecting lower molecular weight and altered viscoelastic behavior. This was further confirmed via Cole–Cole and van Gurp–Palmen plots. In the post-consumer blend, scanning electron microscopy (SEM) showed progressive coalescence of LDPE droplets, contributing to reduced interfacial area and decreased impact resistance. In general, the results showed that virgin PA 11 retains acceptable performance up to three cycles, while the post-consumer blend exhibits faster and more pronounced degradation driven by both chemical and morphological changes particularly due to droplet coalescence and loss of interfacial area.
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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) | 0.000 | 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".