Effect of organized anionic surfactant system on kinetics of polymerization of acrylonitrile initiated by Ce(IV): Citric acid and other organic substrates

✍ Scribed by M. Patra; A. K. Panigrahi; B. K. Sinha

• Publisher: John Wiley and Sons
• Year: 1996
• Tongue: English
• Weight: 444 KB
• Volume: 62
• Category: Article
• ISSN: 0021-8995
• DOI: 10.1002/(sici)1097-4628(19961003)62:1<19::aid-app4>3.0.co;2-v

✦ Synopsis

SYNOPSIS

T h e polymerization of acrylonitrile (AN) using the Ce(1V)-citric acid (CA) redox system as a n initiator in aqueous nitric acid solution, in the presence of a n anionic surfactant, sodium dodecyl sulfate (SDS), has been kinetically studied a t a temperature range of 25-45°C. T h e rate of polymerization (R,) and disappearance of Ce(IV) (-Rce) increase with increasing concentration of SDS, above its critical micelle concentration (cmc), when the surfactant molecules are organized. R, was found to be proportional to [AN]1s and [CAI". With other organic substrates, R, follows the increasing order of sorbitol 2 mannitol > glycerol > CA. But it was found to decrease considerably in the presence of cationic surfactant (CTAB), and nonionic surfactant (Triton-X-100) had no eRect on the rate. -Rc. varies linearly with [Ce(IV)] and [CAI. Both Rp and -Rce increase with increasing temperature. T h e overall activation energy was found to be 18.31 and 13.72 kcal/mol in the absence and presence of 0.015M SDS, respectively. T h e chain length o f t h e polyacrylonitrile has also increased with increasing SDS concentration. (0 1996 .John Wiley & Sons, Inc.