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- MakaleAçık Erişim2025Scopus SJRQ3A study on copolymers of styrene with a methacrylamide containing benzofuran side group: Their monomer reactivity ratios, thermal stabilities, thermal degradation kinetics
Barim, Esra; Demir, Pınar; Değirmenci, Mustafa; Kirilmiş, Cumhur
The aim of this study was to determine the monomer reactivity ratios, thermal properties and thermal degradation behavior of new P(N-[2-(4-brombenzoyl)-benzofuran-3-yl]-2-methac-rylamide-co-styrene) polymers synthesized at different compositions. For this purpose, novel copolymers of N-[2-(4-brombenzoyl)-benzofuran-3-yl]-2-methacrylamide (NBBM) monomer with styrene (St) monomer were prepared using free radical polymerization method. The 1 H-NMR spectra was used to calculate the compositions of the copolymers. The reactivity ratios of monomers were calculated in line with the universal copolymerization equation using Kelen-Tüdös and Finemann-Ross linearization methods, and found to be r1:0,62 r2:1,09 and r1:0,61, r2:1,07 respectively (where r1 is reactivity ratio of NBBM). DSC, TGA and DTG were used to study the thermal behaviors of the copolymers. The Tg value of P(NBMM) was found to be 211oC and the Tg values of the studied copolymers were determined to increase from 144oC to 184oC with increasing concentration of NBMM units. Thermal data showed that the maximum degradation temperatures increased from 349oC to 391oC as the St units increased in the copolymer system. The activation energy (Ea) values of P(NBBM) and the studied copolymer were determined from the TGA curves obtained at different heating rates and the Flynn-Wall-Qzawa, Kissinger, Tang isoconversional methods were used. Solid state reaction mechanisms were also calculated by being used the Van Krevelen method, a non-isoconversion model. The Ea values obtained with isoconversion models for P(NBBM) and copolymer were found very close to the values obtained from non-isoconversion models. Moreover, the R3 mechanism was proposed for the homopolymer and copolymer.
- MakaleYalnız künye2019Scopus SJRQ2Synthesis, characterization and spectroscopic investigation of N-(2-acetylbenzofuran-3-yl)acrylamide monomer: Molecular structure, HOMO–LUMO study, TD-DFT and MEP analysis
Barim, E.; Akman, F.
In this study, a novel acrylamide monomer was synthesized and characterized by UV-Vis, FT-IR and 1H NMR measurements. The acrylamide monomer namely, N-(2-acetyl-benzofuran-3-yl)acrylamide (NABA), was prepared in two steps. In the first step, 1-(3-aminobenzofuran-2-yl)ethan-1-one was synthesized by the reaction of 1-chloroacetone with 2-hydroxy-benzonitrile under basic conditions. In the second step, the obtained 1-(3-aminobenzofuran-2-yl)ethan-1-one was reacted with acryloyl chloride and triethylamine at 0–5 °C temperature for obtaining NABA monomer. Then, the structural, vibrational, nuclear magnetic resonance and electronic properties for the synthesized monomer were determined by quantum chemical calculations of DFT method. The results were compared with experimental FT-IR, 1H NMR and UV–Vis spectral data. The band gap of HOMO and LUMO show that the NABA monomer is chemically active and has charge transfer within the monomer. Moreover, molecular electrostatic potential (MEP) maps were drawn to identify reactive regions of NABA monomer.
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