Influence of Polycarbonate Flexibility on the Annealing-Induced Phase Separation of the Hole Transport Molecule TPD in a Model Charge Transport Composite
Bibliographic record
Abstract
The depression of glass transition temperature, annealing-induced phase separation, and morphology were investigated in a binary solid solution of N,N ‘ - diphenyl- N,N ‘-bis(3-methylphenyl)-[1,1 ‘ -biphenyl]-4,4 ‘ -diamine (TPD) in bisphenol A polycarbonate (BPAPC) and cyclohexyl polycarbonate (PCZ) with three different molecular weights. Differential scanning calorimetry, X-ray diffraction, microscopy, and FTIR were used to characterize these composites. Molecularly doped TPD in polymers significantly depressed the T g of the host polymers. Although it could be expected that the TPD would disperse well in a flexible polymer and cause a substantial decrease in T g, we find that the extent of depression is more pronounced with the rigid polymer. FTIR studies indicate that a molecular level interaction exists between TPD and the polycarbonates, as shown by the frequency shifts in the aromatic region. Upon annealing, the phase separation and crystallization of TPD lead to a recovery of the T g of the polymer, by 10−20 °C, depending on the temperature and time of annealing. In the case of TPD/BPAPC composites, although the crystallinity of the phase-separated TPD was found to be close to 30%, the extent of recovery of the T g was small. This is attributed to the plasticizing effect of the TPD crystals. A lower degree of crystallinity was observed in the case of TPD/PCZ, which is due to the lower molecular flexibility of the PCZ relative to BPAPC as well as the difference between the T g of the polymer and the annealing temperature. The molecular weight and its dispersion has a significant effect on the recovery of the T g in the case of PCZ, as well as the crystallinity of the phase-separated TPD.
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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".