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1094115 
Journal Article 
Non-transition metal-catalyzed living radical polymerization of vinyl chloride initiated with iodoform in water at 25 degrees C 
Percec, V; Popov, AV; Ramirez-Castillo, E; Coelho, JFJ; Hinojosa-Falcon, LA 
2004 
Yes 
Journal of Polymer Science. Part A, Polymer Chemistry
ISSN: 0887-624X
EISSN: 1099-0518 
42 
24 
6267-6282 
English 
WOS:000225510500009 
Non-transition metal-catalyzed living radical polymerization (LRP) of vinyl chloride (VC) in water at 25-35 degreesC is reported. This polymerization is initiated with iodoform and catalyzed by Na2S2O4. In water, S2O42- dissociates into SO2-. that mediates the initiation and reactivation steps via a single electron transfer (SET) mechanism. The exchange between dormant and active propagating species also includes the degenerative chain transfer to dormant species (DT). In addition, the SO2 released from SO2-. during the SET process can add reversibly to poly(vinyl chloride) (PVC) radicals and provide additional transient dormant similar toSO(2)(.) radicals. This novel LRP proceeds mostly by a combination of competitive SET and DT mechanisms and, therefore, it is called SET-DTLRP. Telechelic PVC with a number-average molecular weight (M-n) = 2,000-55,000, containing two active similar toCH(2)-CHCII chain ends and a higher syndiotacticity than the commercial PVC were obtained by SET-DTLRP. This PVC is free of structural defects and exhibits a higher thermal stability than commercial PVC. SET-DTLRP of VC is carried out under reaction conditions related to those used for its commercial free-radical polymerization. Consequently, SET-DTLRP is of technological interest both as an alternative commercial method for the production of PVC with superior properties as well as for the synthesis of new PVC-based architectures. (C) 2004 Wiley Periodicals, Inc. 
living polymerization; radical polymerization; vinyl chloride; poly(vinyl chloride); telechelic; sodium dithionite; iodoform; single electron transfer; degenerative chain transfer; tacticity