Routes to carboxylic acid functional acrylonitrile copolymers via <i>N</i>‐<i>tert</i>‐butyl‐<i>N</i>‐(1‐diethylphosphono‐2,2‐dimethylpropyl) free nitroxide based nitroxide‐mediated polymerization
Bibliographic record
Abstract
Abstract Styrene (S)/acrylonitrile [AN; initial acrylonitrile molar feed compositions ( f AN,0 's) = 0.10–0.86) and tert ‐butyl methacrylate ( t BMA)/AN ( f AN,0 = 0.10–0.80) copolymers were synthesized at 90°C in 50 wt % 1,4‐dioxane solutions with a unimolecular initiator, N ‐(2‐methylpropyl)‐ N ‐(1‐diethylphosphono‐2,2‐dimethylpropyl)‐ O ‐(2‐carboxylprop‐2‐yl) hydroxylamine [BlocBuilder (BB)]. In the t BMA/AN copolymerizations, 8.0–8.5 mol % N ‐ tert ‐butyl‐ N ‐(1‐diethylphosphono‐2,2‐dimethylpropyl) free nitroxide relative to BB was added. The S/AN copolymers exhibited narrow, monomodal molecular weight distributions (MWDs) with low polydispersities [weight‐average molecular weight ( M w )/number‐average molecular weight ( M n ) = 1.14–1.26], and the M n versus monomer conversion ( X ) plots were relatively linear ( M n = 18.1 kg/mol, X ≈ 0.7); this suggested that pseudo‐living behavior was approached. AN proved to be an effective controlling comonomer for t BMA because the t BMA/AN copolymers exhibited narrow monomodal MWDs with M w / M n = 1.17–1.50 and relatively linear M n versus X plots to reasonably high X values ( M n = 15.6 kg/mol, X ≈ 0.6). The AN and S monomer reactivity ratios were r AN = 0.07 ± 0.01 and r S = 0.27 ± 0.02 (Fineman–Ross) and r AN = 0.10 ± 0.01 and r S = 0.28 ± 0.02 (Kelen–Tüdos), respectively; these values were in good agreement with conventional free‐radical polymerization. Error‐in‐variables model (EVM) analysis indicated that the use of cumulative composition S/AN data was more effective than typical approaches using low‐ X data with the Mayo–Lewis model. The AN and t BMA reactivity ratios [ r AN = 0.07 ± 0.01 and r t BMA = 1.24 ± 0.20 (Fineman–Ross) and r AN = 0.14 ± 0.01 and r t BMA = 0.89 ± 0.19 (Kelen–Tüdos)] were similar to those reported for related alkyl methacrylate/AN conventional radical copolymerizations. EVM analysis suggested significant experimental error was associated with the t BMA/AN system, and this warrants further investigation. © 2012 Wiley Periodicals, Inc. J Appl Polym Sci, 2012
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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 | 0.001 | 0.000 |
| Meta-epidemiology (narrow) | 0.001 | 0.001 |
| Meta-epidemiology (broad) | 0.001 | 0.000 |
| Bibliometrics | 0.001 | 0.002 |
| Science and technology studies | 0.001 | 0.001 |
| Scholarly communication | 0.000 | 0.002 |
| Open science | 0.002 | 0.000 |
| Research integrity | 0.000 | 0.001 |
| 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 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".