Ultrasound-assisted emulsion polymerization of poly(methyl methacrylate-co-butyl acrylate): Effect of initiator content and temperature

Abstract

In this study, we propose an efficient method for preparation of large scale, monodisperse poly(methyl methacrylate-co-butyl acrylate) latexes by application of the low power ultrasound irradiation. The effect of polymerization temperature and initiator concentration on the polymerization nature, particle size, and particle size distribution were investigated. Results indicated that the ultrasound pulses in the first minutes of polymerization increase instant free radical to monomer ratio as well mixing efficiency which led to higher monomer conversion, improved polymerization rate (especially at first 15 min of the reaction), and remarkable decrease in molecular weight distribution. Transmittance electron microscopy (TEM) and dynamic light scattering (DLS) revealed that the particle size and particle size distribution were significantly affected, particle size decreased, and more uniform particles were obtained. Dynamic mechanical thermal analysis also showed that the initiator concentration affected glass transition temperature (T g ) of the final copolymers and in the case of ultrasound-assisted emulsion polymerization T g was in a very good agreement with theoretical predictions for copolymerization. POLYM. ENG. SCI., 56:214-221, 2016.

Nanostructured Copper Selenide Coatings for Antifouling Applications

“…The detailed analysis of the spectrum shows characteristic signals at 2958 cm -1 , 2882 cm -1 , 1730 cm -1 , 1448 cm -1 and 1152 cm -1 , where the first two are attributed to stretching of the -CH group, while the third one belongs to the stretching of the C=O group and the fourth signal is due to stretching of the -CH3 group as well as the last one is due to the stretching and vibrations of O-CH3 corresponding to the ester group. The presence of the band at 3446 cm -1 suggests the presence of hydroxyl groups (-OH) or water molecules trapped in the test material [31]. The bands described are characteristic of polymethylmethacrylate (PMMA), however, the absorption band at 961 cm -1 is typical of polybutylacrylate (PBA), this band is due to the oscillation of the carbon of the -COO group of the PBA, as found in the literature [32].…”

Nanostructured Copper Selenide Coatings for Antifouling Applications

“…Polymers 2024, 16, x FOR PEER REVIEW 6 of 19 the presence of hydroxyl groups (-OH) or water molecules trapped in the test material [35]. The bands described are characteristic of polymethylmethacrylate (PMMA); however, the absorption band at 961 cm −1 is typical of polybutylacrylate (PBA), and this band is due to the oscillation of the carbon of the -COO group of the PBA, as found in the literature [36].…”

“…The detailed analysis of the spectrum shows characteristic signals at 2958 cm −1 , 2882 cm −1 , 1730 cm −1 , 1448 cm −1 , and 1152 cm −1 , where the first two are attributed to the stretching of the -CH group, the third one belongs to the stretching of the C=O group, the fourth signal is due to the stretching of the -CH 3 group, and the last one is due to the stretching and vibrations of O-CH 3 corresponding to the ester group. The presence of the band at 3446 cm −1 suggests the presence of hydroxyl groups (-OH) or water molecules trapped in the test material [ 35 ]. The bands described are characteristic of polymethylmethacrylate (PMMA); however, the absorption band at 961 cm −1 is typical of polybutylacrylate (PBA), and this band is due to the oscillation of the carbon of the -COO group of the PBA, as found in the literature [ 36 ].…”

Síntese via polimerização in situ e caracterização de nanocompósitos condutores elétricos de poli(metacrilato de metila) em função do teor de nanotubos de carbono e da energia ultrassônica

“…MAHDAVIAN, 2016;LINAN et al 2015;ODIAN, 1991). Além disso, com a elevação da temperatura, a taxa de terminação por desproporcionamento aumenta em relação à taxa de terminação por combinação, o que pode contribuir para a variação da massa molar polimérica.Outro fator que pode ter contribuído para redução da massa molar dos polímeros sintetizados neste trabalho é a presença de oxigênio no meio reacional.Ainda que se tenha borbulhado gás nitrogênio a fim de promover atmosfera inerte, o procedimento pode não ter sido suficiente para garantir que todo o oxigênio fosse de fato removido da solução.…”