The effect of depth and duration of UV radiation on polypropylene modification via photoinitiation
Bibliographic record
Abstract
ABSTRACT Linear polypropylene (PP) was modified using UV radiation in the presence of 0.5 wt % of benzophenone photoinitiator to introduce long chain branching (LCB) to the PP backbone. Irradiation was carried out in the solid state and the temperature level was kept below 60°C. The effects of radiation duration and sample thickness on the extent of these branching modification reactions were investigated. Viscoelastic properties, molecular weight, molecular weight distribution, and gel content were determined and compared for runs having different sample thicknesses, irradiated for different times. Comparisons were also conducted with the parent PP and the PP mixed with photoinitiator. It was found that LCB decreased by increasing the thickness of the samples. Conversely, an increase in radiation duration resulted in enhanced LCB but also led to larger gel content in the samples. Based on all these measurements and observations, a mechanism was suggested to explain formation of long chain branches (LCBs) in PP in the solid state via photoinitiation. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014, 131, 41021.
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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) | 0.001 | 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 | 0.000 |
| 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".