Kinetics of azo-initiated 1-vinyl-2-pyrrolidone polymerizations at low conversions in aqueous media

✍ Scribed by J. C. Cizravi; Tiam Yeng Tay; Eng Ching Pon

• Publisher: John Wiley and Sons
• Year: 2000
• Tongue: English
• Weight: 172 KB
• Volume: 75
• Category: Article
• ISSN: 0021-8995
• DOI: 10.1002/(sici)1097-4628(20000110)75:2<239::aid-app6>3.0.co;2-y

✦ Synopsis

The free-radical polymerization behavior of 1-vinyl,2-pyrrolidone (NVP) was studied at low conversions, using capillary dilatometry. The aqueous media were kept at neutral pH and the studies were conducted isothermally, at 40 or 45°C. The azo-type initiators used were 4,4Ј-azobis-4-cyanopentanoic acid (ACPA), 2,2Ј-azobisisobutyronitrile (AZBN), and 2,2Ј-azobis[2-(2-imidazolin-2-yl)propane dihydrochloride] (ABDH). The monomer concentration and initiator concentration ranges were 1.17-2.34 mol L Ϫ1 and 1-8 mmol L Ϫ1 , respectively. The rates of polymerization (R p ) and orders of reaction with respect to NVP and the initiator were evaluated and the kinetic equations were found to be R

The polymers obtained were characterized by their viscosity numbers and correlation of the viscosity average molecular weights made with the type and amount of the azo initiator.