title: Reactivity of heteropolymolybdates and heteropolytungstates in the cationic polymerization of styrene.
abstract: The two heteropolyacids H(3)PW(12)O(40) and H(3)PMo(12)O(40), and their homologous salts (NH(4))(3)PW(12)O(40), and (NH(4))(3)PMo(12)O(40) were prepared and tested in the cationic polymerization of styrene. The results showed that the heteropolytungstates were more reactive than the heteropolymolybdates. It has been found that the yield and the viscosity average molecular weight (M(v)) of polystyrene are directly proportional to the acidity strength of the heteropolyanions (H(3)PW(12)O(40) > H(3)PMo(12)O(40) > (NH(4))(3)PW(12)O(40) > (NH(4))(3)PMo(12)O(40)). The highest yield (68.0%) and M(v) (7,930) were obtained by using H(3)PW(12)O(40). In addition, H(3)PW(12)O(40) polymerized the styrene under mild conditions and was recyclable, and could behave as a truly heterogeneous catalyst.
authors.affiliation: Chemistry Department, College of Science, King Saud University, Riyadh, Saudi Arabia. aouissed@yahoo.fr
authors.forename: Ahmed
authors.initials: A
authors.lastname: Aouissi
authors.forename: Zeid Abdullah
authors.initials: ZA
authors.lastname: Al-Othman
authors.forename: Holeil
authors.initials: H
authors.lastname: Al-Anezi
mesh_terms: D002412:Cations; D003247:Conservation of Natural Resources; D008970:Molecular Weight; D008982:Molybdenum / Q000737:chemistry*; D011108:Polymers / Q000737:chemistry*; D011137:Polystyrenes / Q000138:chemical synthesis*; D020058:Styrene / Q000737:chemistry; D017973:Tungsten Compounds / Q000737:chemistry*
chemical_list: D002412:Cations; D011108:Polymers; D011137:Polystyrenes; D017973:Tungsten Compounds; D020058:Styrene; D008982:Molybdenum; C045951:tungstate