The Free-Radical Nonbranched-Chain Initiated Formation of Ethylene Glycol from Methanol–Formaldehyde Solutions
Bibliographic record
Abstract
The mechanism and kinetics are developed for the free-radical nonbranched-chain initiated formation of ethylene glycol in methanol–formaldehyde solutions at formaldehyde concentrations of 0.1-3.1 mol dm-3 and temperatures of 373-473 K. The experimental concentrations of the free unsolvated form of formaldehyde are given at the different temperatures and total concentrations of formaldehyde in methanol. The experimental dependence of the radiation-chemical yields of ethylene glycol on formaldehyde concentration in γ-radiolysis of methanol-formaldehyde solutions at 373-473 K is shown. At a formaldehyde concentration of 1.4 mol dm-3 and T = 473 K, the radiation-chemical yield of ethylene glycol is 139 molecules per 100 eV. The effective activation energy of ethylene glycol formation is 25 ± 3 kJ mol-1. The quasi-steady-state treatment of the reaction network suggested here led to a rate equation accounting for the non-monotonic dependence of the ethylene glycol formation rate on the concentration of the free (unsolvated) form of dissolved formaldehyde. It is demonstrated that the peak in this dependence is due to the competition between methanol and CH2=O for reacting with adduct radical HOCH2CH2O-¢.
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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".