Semicontinuous Heterophase Polymerization of Methyl and Hexyl Methacrylates to Produce Latexes with High Nanoparticles Content

Low-temperature polymerization of methyl methacrylate emulsion gels through surfactant catalysis

“…In contrast, water caused phase separation in styrene/fumed silica gels [9]. MMA is slightly soluble in water [20], and might act like a cosurfactant to stabilize some water in the sample [21]. Thus, a stable MMA/water/fumed silica gel was formed without adding surfactants.…”

Synthesis, Characterization, and Drug Delivery from pH- and Thermoresponsive Poly(N-Isopropylacrylamide)/Chitosan Core/Shell Nanocomposites Made by Semicontinuous Heterophase Polymerization

“…Semicontinuous heterophase polymerization (SHP) is a variation of the semicontinuous microemulsion polymerization (SMP), which allows the synthesis of polymer nanoparticles and nanocomposites smaller than 50 nm with narrow size distributions, employing smaller amounts of surfactant and larger polymer-to-surfactant ratios compared to the SMP [24][25][26][27][28]. In this process and in contrast to the SMP, neat monomer is dosed at a controlled rate to an aqueous (or oleic) solution containing surfactant forming micelles, initiator, and a solvent-soluble initiator.…”

“…An important feature of the SHP is that narrower particle size distributions with smaller molar masses, compared to SMP, are obtained. The SHP process has been proved successfully to synthesize a series of poly(alkyl methacrylates) that have anomalously higher glass transition temperatures, indicating a larger syndiotactic polymer content [24][25][26][27][28], semiconducting polypyrrole [29], mesoporous nanoparticles [30], and polymeric nanocomposites [31].…”

Tunable mechanical properties of core‐shell polymers of poly(hexyl methacrylate) and poly(methyl methacrylate) by semicontinuous heterophase polymerization

“…In addition to emulsion polymerization, microemulsion polymerization is also been to produce core/shell materials with a nanometer size. New polymerization methods have also been reported to produce nano‐polymers with a smaller particle size distribution, such as the so called semicontinuous heterophase polymerization , which allows the synthesis of nanoparticles and semiconducting nano‐polymers smaller than 50 nm and narrow size distributions . In this process, monomer is added at a controlled rate to an aqueous solution containing initially only the surfactant and a water‐soluble initiator; the process is characterized by feeding at a slow rate to achieve monomer‐starved conditions.…”