ABSTRACT: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 p ϰ

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 p ϰ [NVP] [ACPA] 1.2 ; R p ϰ [NVP] [AZBN] 1.1 ; and R p ϰ [NVP] 2.2 [ABDH] 1.1 . 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.

No abstract