New Type Of Bisphenol A-Free Vinyl Ester Resin
Bibliographic record
Abstract
Vinyl ester resins (VER) are high-performance unsaturated resins obtained by the addition reaction of various epoxy resins with - unsaturated carboxylic acids. VERs have remarkable corrosion resistance and improved physical properties over conventional unsaturated polyester resins, making VERs in a class of their own and a hallmark of today's resin industry Bisphenol A (BPA) is a precursor in the production of VER resins There is growing evidence that BPA can adversely affect humans Recent studies indicate that exposure to bisphenol A in adults may be associated with reduced ovarian response, miscarriage or premature birth, reduced sexual function in men, altered levels of sex hormones and thyroid, and cardiovascular disease The subject of the research is to obtain a VER resin free of bisphenol A. For this purpose, the modification of the end carboxyl groups in the chains of unsaturated polyesters with glycidyl methacrylate (GMA) was carried out GMA was introduced in the presence of a catalyst -quaternary phosphonium salt, which was added in two portions: at the beginning and in the middle of the process. In order to protect glycidyl methacrylate against polymerization, an inhibition system composed of: tert-butylhydroquinone: naphthoquinone was used. The course of the reaction was monitored by infrared spectroscopy. On the basis of the spectra, the disappearance of the bands originating from the epoxy groups was observed. After completion of the process, the obtained vinyl polyester was cross-linked with styrene. The obtained polymeric materials with different content of cross-linking monomer were tested for the assessment of mechanical and thermal properties as well as hardness and changes in gloss. The aim of the research was to check whether the obtained material has properties comparable to commercial vinyl ester resins based on bisphenol A.
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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) | 0.001 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.001 | 0.000 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.000 | 0.001 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.001 | 0.001 |
| Insufficient payload (model declined to judge) | 0.002 | 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".