title: Sonolytic and silent polymerization of methacrlyic acid butyl ester catalyzed by a new onium salt with bis-active sites in a biphasic system--a comparative investigation.
abstract: Currently, ingenious new analytical and process experimental techniques which are environmentally benign techniques, viz., ultrasound irradiation, have become immensely popular in promoting various reactions. In this work, a novel soluble multi-site phase transfer catalyst (PTC) viz., 1,4-bis-(propylmethyleneammounium chloride)benzene (BPMACB) was synthesized and its catalytic efficiency was assessed by observing the kinetics of sonolytic polymerization of methacrylic acid butyl ester (MABE) using potassium persulphate (PPS) as an initiator. The ultrasound-multi-site phase transfer catalysis (US-MPTC)-assisted polymerization reaction was compared with the silent (non-ultrasonic) polymerization reaction. The effects of the catalyst and various reaction parameters on the catalytic performance were in detail investigated by following the kinetics of polymerization of MABE in an ethyl acetate-water biphasic system. From the detailed kinetic investigation we propose a plausible mechanism. Further the kinetic results demonstrate clearly that ultrasound-assisted phase-transfer catalysis significantly increased the reaction rate when compared to silent reactions. Notably, this environmentally benign and cost-effective process has great potential to be applied in various polymer industries.
authors: Department of Safety, Health and Environmental Engineering, Hungkuang University, Shalu District, Taichung City 43302, Taiwan.
authors: Perumberkandgai A
authors: PA
authors: Vivekanand
authors: Maw-Ling
authors: ML
authors: Wang
authors: Yu-Ming
authors: YM
authors: Hsieh
mesh_terms: D000643:Ammonium Chloride / Q000737:chemistry*; D002384:Catalysis; D020134:Catalytic Domain; D004952:Esters; D005609:Free Radicals / Q000737:chemistry; D006863:Hydrogen-Ion Concentration; D008689:Methacrylates / Q000737:chemistry*; D009994:Osmolar Concentration; D044367:Phase Transition; D058105:Polymerization; D017680:Potassium Compounds / Q000737:chemistry; D012997:Solvents / Q000737:chemistry; D013431:Sulfates / Q000737:chemistry; D013696:Temperature; D013997:Time Factors; D014465:Ultrasonics / Q000379:methods*; D014867:Water / Q000737:chemistry
chemical_list: D004952:Esters; D005609:Free Radicals; D008689:Methacrylates; D017680:Potassium Compounds; D012997:Solvents; D013431:Sulfates; D000643:Ammonium Chloride; D014867:Water; C008384:methacrylic acid; C009007:potassium persulfate