title: Preparation of CO₂/N₂-triggered reversibly coagulatable and redispersible polyacrylate latexes by emulsion polymerization using a polymeric surfactant.
abstract: We report here a novel approach for making reversibly coagulatable and redispersible polyacrylate latexes by emulsion (co)polymerization of methyl methacrylate (MMA) using a polymeric surfactant, poly(2-(dimethylamino)ethyl methacrylate)(10) -block-poly(methyl methacrylate)(14) . The surfactant was protonated with HCl prior to use. The resulted PMMA latexes were readily coagulated with trace amount of caustic soda. The coagulated latex particles, after washing with deionized water, could be redispersed into fresh water to form stable latexes again by CO(2)  bubbling with ultrasonication. The recovered latexes could then be coagulated by N(2)  bubbling with gentle heating. These coagulation and redispersion processes were repeatable by the CO(2) /N(2)  bubbling.
authors.affiliation: State Key Lab of Chemical Engineering, Institute of Polymerization and Polymer Engineering, Department of Chemical and Biological Engineering, Zhejiang University, Hangzhou, Zhejiang 310027, P R China.
authors.forename: Qi
authors.initials: Q
authors.lastname: Zhang
authors.forename: Guoqiang
authors.initials: G
authors.lastname: Yu
authors.forename: Wen-Jun
authors.initials: WJ
authors.lastname: Wang
authors.forename: Bo-Geng
authors.initials: BG
authors.lastname: Li
authors.forename: Shiping
authors.initials: S
authors.lastname: Zhu
mesh_terms: D000180:Acrylic Resins / Q000737:chemistry*; D002245:Carbon Dioxide / Q000737:chemistry*; D004655:Emulsions / Q000737:chemistry*; D008689:Methacrylates / Q000737:chemistry; D008863:Microspheres; D009584:Nitrogen / Q000737:chemistry*; D009757:Nylons / Q000737:chemistry; D058105:Polymerization; D019904:Polymethyl Methacrylate / Q000737:chemistry; D013501:Surface-Active Agents / Q000737:chemistry*
chemical_list: D000180:Acrylic Resins; D004655:Emulsions; D008689:Methacrylates; D009757:Nylons; D013501:Surface-Active Agents; C407037:poly(2-(dimethylamino)ethyl methacrylate); D002245:Carbon Dioxide; C006903:carbopol 940; D019904:Polymethyl Methacrylate; D009584:Nitrogen