Kinetics of emulsion polymerization of styrene using the reactive surfactant HITENOL BC20

Abstract

The effect of the reactive surfactant HITE-NOL BC20 (polyoxyethylene alkylphenyl ether ammonium sulfate; 20 U of ethylene oxide (EO)) on the emulsion polymerization of styrene was studied via reaction calorimetry (Mettler RC1; 708C). For polymerizations carried out above the cmc of BC20, the reaction kinetics and evolution of the number of particles (N p ) resembled those reported using the conventional surfactant sodium lauryl sulfate, indicating that nucleation proceeded by a combination of micellar and homogenous nucleation (Interval I and Stage 2). The reaction rate (R p ) not only increased with increasing initiator (K 2 S 2 O 8 ) and surfactant concentrations, as expected, but the increase in rate in Stage 2 was dependent on the initiator concentration and independent of the surfactant concentration. This is consistent with the proposed nucleation mechanisms. The molecular weight increased with increasing surfactant concentration and decreasing initiator concentration as would also be expected for a conventional surfactant. The dependencies of R p and N p on the BC20 and initiator concentrations, however, were lower than the classical Smith-Ewart values (0.21-0.25 ) although R p was found to be directly proportional to N p . Chain transfer to the reactive surfactant is considered a likely source of divergence.

Semicontinuous heterophase polymerization of methyl methacrylate in the presence of reactive surfactant HITENOL BC10

“…However, Lai et al [8] using the reactive surfactant polyoxyethylene alkylphenyl ether ammonium sulfate; 20 Units of ethylene oxide (HBC20) in the batch emulsion polymerization of styrene, observed that the molecular weight increased with increasing surfactant concentration. This behavior was explained by the decreased radical entry rate per particle as more particles are produced with increasing surfactant.…”

“…For example, Lai et al [8] studied the emulsion polymerization of styrene using HITENOL BC20 as reactive surfactant above the CMC. They observed that particle nucleation was similar to that reported using the conventional surfactant SDS.…”

“…Some negative effects of the presence of conventional surfactants in latex are foaming and migration to interfaces during film formation, giving as a result, water-sensitivity. These deficiencies can be largely reduced or eliminated by chemically incorporating the surfactant into the latex particles [8].…”

Efecto del Uso de Surfactantes Polimerizables en la Distribución de Tamaño de Partícula, pH, Viscosidad, Contenidos de Sólidos y de Monómero Residual de una Resina Estireno-Butilacrilato

“…Estos grupos funcionales son localizados generalmente al final de la secuencia hidrofóbica mientras que la estructura hidrofílica es compuesta por poli oxido de etileno. Algunos de los grupos funcionales de mayor uso son del tipo alílico, maléico, metacrílico y vinílico [9][10][11][12][13][14][15][16] . Debido a que los surfactantes polimerizables quedan fijos en las estructura del polímero, no representan ningún riesgo ambiental.…”

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

“…Some negative effects of the presence of conventional surfactants in the latex are foaming and migration to interfaces during film formation, resulting in water sensitivity [6]. These deficiencies can be reduced or eliminated by covalent bonding of surfactant molecules into the latex particles [7].…”