SYNTHESIS OF POLY (L-LACTIC ACID) BY EHYDROPOLYCONDENSATION, DETERMINATION OF SEQUENCE BY 13C NMR METHOD
Bibliographic record
Abstract
The proposed work was undertaken to synthesize high molecular weight PLA by direct polycondensation to find its better applicability in fiberapplication, packaging material and commodity. However, it was reported that it was very difficult to obtain high molecular weight PLA by directpolycondensation because of equilibrium between free acids, water and polyesters causing difficulty in removing water as a by-product. The effectof various solvents (polar and non polar) and reaction temperatures were also investigated. In this contribution, the influence of process variableson the molecular weight of PLA synthesized by direct polycondensation will be highlighted. We report the use of high-resolution 13C-NMR (125MHz) spectroscopy to identify the sterosequence distribution and determine stereo specific preference for L-lactic acid addition during tin chloridedihydrate (SnCl2.2H2O) catalyzed polymerization, and effect of various specific polymerization conditions such as temperature, duration of reactionand the nature of solvents.
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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 | 0.001 |
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".