Ultrasound-assisted polymerization of methyl methacrylate using the reactive surfactant Hitenol BC10 in a semicontinuous heterophase process

Abstract

with R a ; however, monomer-starved conditions were favored at lower R a values. Very high-average molecular weights were observed (1.63 × 10 6 ≤ M w ≤ 2.34 × 10 6 g/ mol) which decreased when HBC10 concentration increased, and increased with R a . The corresponding polydispersity indexes (M w /M n ) were in the range of 1.55-2.30, showing relatively wide molar masses distributions. It was observed from differential scanning calorimetry that polymers with HBC10 presented two T g (123 and 178 °C) which was ascribed to HBC10 incorporated to PMMA chain, corroborated by 1 H NMR.

Synthesis of sulfonated poly(styrene‐co‐methyl methacrylate) by semicontinuous heterophase polymerization for filtration membranes

“…Since Rp is proportional to the number of polymer particles, when increasing the initial charge of Latemul ® PD-104, polymerization rate and the instantaneous conversion decreased. On the other hand, Vargas-Salazar et al [39] and Aguirreurreta et al, [40] observed a considerable reduction in the water absorption of the formed films using the polymers obtained in the presence of polymerizable surfactants compared to those with polymers from the synthesis with conventional surfactants, indicating the correct chemical incorporation of surfactant to polymer chains.…”

“…It has been reported that for some polymerizable surfactants, chain transfer reactions to the allyl double bond contribute to the reaction rate reduction. For example, Vargas-Salazar et al [39] polymerized MMA in the presence of HBC10 in a semicontinuous heterophase process assisted by ultrasound to obtain latexes with polymer contents of 24%. The conversions obtained for the polymerizations where the weight ratio of HBC10/MMA and the monomer addition rate were varied between 80% and 90%.…”