ISSN:
1022-1352
Schlagwort(e):
Chemistry
;
Polymer and Materials Science
Quelle:
Wiley InterScience Backfile Collection 1832-2000
Thema:
Chemie und Pharmazie
,
Physik
Notizen:
The effect of an organized anionic surfactant, i.e. sodium dodecyl sulfate (SDS), on the acrylamide (AM) polymerization initiated with the redox system Ce(IV)-cyclohexanone (CH) in aqueous nitric acid was kinetically studied over a temperature range of 25-45°C. With increasing concentration of SDS, above its critical micelle concentration (CMC) the rate of polymerization, Rp(obs), as well as the rate of Ce(IV) consumption, -RCe(obs), were found to increase, while in the presence of cetyltrimethylammonium bromide (CTAB) these rates decreased considerably. Rp(obs) is proportional to [Ce(IV)]0.5, [CH]0.5 and [AM]1.5. -RCe(obs) also increases with increasing concentration of Ce(IV), cyclohexanone and acrylamide. The overall activation energy for the process, in the presence and absence of 15 × 10-3 M of SDS, was calculated to be 15.1 and 21.4 kcal/mol, respectively. The viscosity average molecular weight of polyacrylamide was found to increase with increasing SDS concentration. A suitable mechanistic scheme for the polymerization process is proposed.
Zusätzliches Material:
6 Ill.
Materialart:
Digitale Medien
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