title: Polycondensation of dicarboxylic acids and diols in water catalyzed by surfactant-combined catalysts and successive chain extension.
abstract: Direct dehydration polycondensation of dicarboxylic acids and alcohols was carried out by surfactant-combined Brønsted and Lewis acids. This procedure did not require the removal of water, because the esterification was established at the interface of the emulsion in water. Emulsion polycondensations of 1,9-nonanediol (1,9-ND) and dodecanedioic acid (DDA) (the molar ratio of dicarboxylic acid to diol = 1:1) were carried out at 80 degrees C for 48 h in the presence of 16 wt % DBSA. The corresponding polyester (M(w) = 10.1 x 10(3)) was obtained in an excellent yield (99%). Chain extension in the emulsion was carried out using hexamethylene diisocyanate as the chain extender. SEC measurements indicated the expected shift to higher molecular weight region (M(w) = 11.4 x 10(3), M(w)/M(n) = 3.4) compared with parent polyester (M(w) = 4.5 x 10(3), M(w)/M(n) = 2.2).
authors.affiliation: Department of Environmental Technology and Urban Planning, Graduate School of Engineering, Nagoya Institute of Technology, Gokiso-cho, Showa-ku, Nagoya 466-8555, Japan. takasu.akinori@nitech.ac.jp
authors.forename: Akinori
authors.initials: A
authors.lastname: Takasu
authors.forename: Aki
authors.initials: A
authors.lastname: Takemoto
authors.forename: Tadamichi
authors.initials: T
authors.lastname: Hirabayashi
mesh_terms: D000438:Alcohols / Q000737:chemistry*; D002384:Catalysis; D003998:Dicarboxylic Acids / Q000737:chemistry*; D004655:Emulsions; D015394:Molecular Structure; D013501:Surface-Active Agents / Q000737:chemistry*; D014867:Water / Q000737:chemistry
chemical_list: D000438:Alcohols; D003998:Dicarboxylic Acids; D004655:Emulsions; D013501:Surface-Active Agents; D014867:Water