Aqueous emulsion polymerization of styrene in the presence of half-titanocenes which CpTiCl3, (CpCH2CH2OCH3)TiCl3, and of the titanocene (Ph)(2)C[(Cp)(Flu)Ti]Cl-2 is effected. The polymer features are compared with those of polystyrene obtained in the same reaction conditions, by using Cp2TiCl2 as initiator.Titanocene (Ph)(2)C[(Cp)(Flu)Ti]Cl-2 does not show any activity in styrene polymerization. On the contrary, by using both half-titanocenes CpTiCl3 and (CpCH2CH2OCH3)TiCl3, stereoirregular polystyrene is produced. Aqueous emulsion polymerization of substituted styrenes (3-methyl-styrene, 4-methyl-styrene, 3-chloro-styrene, 4-chloro-styrene) is also performed in the presence of Cp2TiCl2. From all monomers, stereoirregular polymers are obtained. Monomer reactivity results dependent on the substituent on the aromatic ring. Aqueous emulsion styrene - 4-chloro-styrene copolymerizations are performed by using Cp2TiCl2, too. Copolymer composition totally reflects that of comonomers used in the feeding. According to a statistical distribution of comonomers, the product of the reactivity ratios is 1.1. (C) 2013 Elsevier Ltd. All rights reserved.
Aqueous emulsion polymerization of styrene and substituted styrenes using titanocene compounds
Pragliola S.
;Longo P.
2013
Abstract
Aqueous emulsion polymerization of styrene in the presence of half-titanocenes which CpTiCl3, (CpCH2CH2OCH3)TiCl3, and of the titanocene (Ph)(2)C[(Cp)(Flu)Ti]Cl-2 is effected. The polymer features are compared with those of polystyrene obtained in the same reaction conditions, by using Cp2TiCl2 as initiator.Titanocene (Ph)(2)C[(Cp)(Flu)Ti]Cl-2 does not show any activity in styrene polymerization. On the contrary, by using both half-titanocenes CpTiCl3 and (CpCH2CH2OCH3)TiCl3, stereoirregular polystyrene is produced. Aqueous emulsion polymerization of substituted styrenes (3-methyl-styrene, 4-methyl-styrene, 3-chloro-styrene, 4-chloro-styrene) is also performed in the presence of Cp2TiCl2. From all monomers, stereoirregular polymers are obtained. Monomer reactivity results dependent on the substituent on the aromatic ring. Aqueous emulsion styrene - 4-chloro-styrene copolymerizations are performed by using Cp2TiCl2, too. Copolymer composition totally reflects that of comonomers used in the feeding. According to a statistical distribution of comonomers, the product of the reactivity ratios is 1.1. (C) 2013 Elsevier Ltd. All rights reserved.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.