High Glass Transition of Fluorinated Polyimides Derived from 4‐(3,4‐Difluorophenyl)‐2,6‐bis(4‐aminophenyl)pyridine
Bibliographic record
Abstract
Abstract A series of novel fluorinated polyimides ( PIs ) were prepared from 4‐(3,4‐difluorophenyl)‐2,6‐bis(4‐aminophenyl)pyridine ( FPAP ) and commercial aromatic dianhydrides via conventional two‐step thermal imidization technique. The structure of the monomer was confirmed by FT‐IR , NMR , and mass spectrometry. All of the obtained PIs were studied with FT‐IR , TGA , DSC , WAXD and contact angles analysis. These results showed that polymer materials presented excellent thermal properties with the glass transition temperature ( T g ) in the range of 336—434 °C, as well as T 5% , and T 10% decomposition temperature ranges of 543—600 °C and 562—622 °C in a nitrogen atmosphere, respectively. Moreover, they presented excellent mechanical properties with tensile strengths of 68—91 MPa , elongation at break of 5.6%—10.2%, and young's modulus of 1.8—2.4 GPa . Furthermore, they showed outstanding hydrophobicity with the contact angle in the range of 90.5°—96.6°, and the results of WAXD indicated all of the polymers presented amorphous structure.
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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".