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Record W2069853338 · doi:10.1081/ppt-120004368

Molecular modeling of the glass transition of stereoregular PMMAs

2002· article· en· W2069853338 on OpenAlex

Why this work is in the frame

A frame that forgets how it found something cannot be audited. These are the routes that admitted this work.

affAt least one author lists a Canadian institution in the pinned OpenAlex snapshot.

Bibliographic record

VenuePolymer-Plastics Technology and Engineering · 2002
Typearticle
Languageen
FieldMaterials Science
TopicMaterial Dynamics and Properties
Canadian institutionsUniversité de Sherbrooke
Fundersnot available
KeywordsGlass transitionMaterials scienceTransition (genetics)Composite materialPolymer chemistryChemistryPolymer

Abstract

fetched live from OpenAlex

Molecular dynamics simulations were performed on PMMA chains of different tacticity to investigate the glass transition phenomenon. Since the difference in the simulated T(g)s between the two stereomers is accurately expressed, microscopic investigations accountable for such a variation can be performed. In this paper, energetic and local dynamics analyses are carried out. From energetic studies, it is shown that the principal energy difference between the two stereomers stays on intermolecular interactions and on the bending energy term associated with the intra-diad angle. A more important opening of this angle was observed for isotactic chains. Such a result has actually to be correlated with the local dynamics behavior of both stereomer chains. For that purpose, relaxation studies were carried out. The isotactic side-chains are shown to rotate with a higher frequency than the syndiotactic ones. Actually, from experimental NMR data, it was shown that the side-chain rotation greatly influences the backbone mobility. Consequently, according to the free volume theory, simulation results perfectly agree with the difference in T(g)s between the two configurations.

Fetched live from OpenAlex and de-inverted. Abstracts are not stored in this database: the inverted indexes are 8.6 GB of the frame’s 9.3 GB of text, and the host has 13 GB free.

Full frame distilled prediction

Teacher imitation

Not 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.

metaresearch head score (Codex)0.000
metaresearch head score (Gemma)0.000
Version: codex-gemma-dda1882f352aValidation status: machine_predicted_unvalidated
Candidate categoriesnone
Consensus categoriesnone
DomainCandidate signal: none · Consensus signal: none
Study designCandidate signal: Bench or experimental · Consensus signal: Bench or experimental
GenreCandidate signal: Empirical · Consensus signal: Empirical
Teacher disagreement score0.394
Threshold uncertainty score0.258

Codex and Gemma teacher scores by category

CategoryCodexGemma
Metaresearch0.0000.000
Meta-epidemiology (narrow)0.0000.000
Meta-epidemiology (broad)0.0000.000
Bibliometrics0.0000.000
Science and technology studies0.0000.000
Scholarly communication0.0000.000
Open science0.0000.000
Research integrity0.0000.000
Insufficient payload (model declined to judge)0.0000.000

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.

Opus teacher head0.006
GPT teacher head0.156
Teacher spread0.151 · how far apart the two teachers sit on this one work
Validation statusscore_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from it