<sup>1</sup>H Solid State NMR Study of Poly(methacrylic acid) Hydrogen-Bonded Complexes
Bibliographic record
Abstract
The hydrogen bond structure of a series of poly(methacrylic acid) (PMAA) complexes was studied by solid-state NMR. 13 C and 2 H labeled PMAA samples were complexed with poly(ethylene oxide) (PEO), poly(vinyl methyl ether) (PVME), poly(acrylamide) (PAAM), poly(vinyl caprolactam) (PVCL) and poly(vinylpyrrolidone) (PVPon). The presence and relative strengths of PMAA’s hydrogen bonds with itself versus those with the complementary polymer was assessed by combining 13 C CP-MAS NMR, 1 H– 13 C HETCOR, 1D and 2D DQ 1 H MAS NMR experiments. Analyses of 1 H DQ spinning sideband patterns gave estimates of the proton–proton distances. Only the polyether–PMAA complexes, PEO and PVME, show resolved 13 C and 1 H resonances. This spectral resolution is proposed to be due to the selective disruption and stabilization of PMAA’s open and cyclic dimers, respectively. Residual PMAA dimers are detected by 1 H NMR for the polylactam complexes, PVCL and PVPon, but both types dimers are weakened, reflecting the greater amount of interpolymer linkages. The PAAM–PMAA complex maintains more of the weaker hydrogen bonds. The role of the different hydrogen bond structures in the relative stabilities and dynamic properties within this series of PMAA complexes and multilayers is assessed.
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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".