The behavior of thiophenol and aliphatic thiols of different structure as chain transfer agents in the polymerization of acrylamide and 1vinyl-2-pyrrolidone in aqueous solution at 25 8C was studied. Addition of millimolar concentrations of thiols to acrylamide polymerization reduced notably the poly
Iodoform as a transfer agent in radical polymerizations
β Scribed by C.A. Barson; J.C. Bevington; B.J. Hunt
- Publisher
- Elsevier Science
- Year
- 1996
- Tongue
- English
- Weight
- 477 KB
- Volume
- 37
- Category
- Article
- ISSN
- 0032-3861
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β¦ Synopsis
Iodoform has been examined as a reactive transfer agent in the radical polymerizations at 60Β°C of styrene and methyl methacrylate using azobisisobutyronitrile as initiator. The transfer constants have been determined by a procedure depending upon the determination of the initiator fragments incorporated as end-groups in the polymers. The polymerizations are retarded by iodoform; this effect is largely caused by an impurity, most probably elemental iodine, which is generated in the polymerizing systems by decomposition of the transfer agent. It is deduced that the transfer constants for iodoform with styrene and methyl methacrylate are ca. 10 and 3, respectively.
π SIMILAR VOLUMES
Generic approaches to the synthesis of multi-thiocarbonyl thio compounds are described. A multi-hydroxy core was condensed with either a-bromophenyl acetic acid or 2-mercaptopropanoic acid in the presence of p-toluenesulfonic acid catalyst to afford the corresponding esters in quantitative yield. Tr
Chain transfer involving thiourea in radical polymerization of methyl methacrylate in acidic aqueous media has been studied by polymer endgroup analysis using the dye-partition technique. Thiourea has feeble reactivity in chain transfer, the transfer constant with respect to poly (methyl methacrylat