The kinetics of the inverse emulsion photopolymerization of acrylamide using the water soluble photoinitiator (triplet radical generator) ct-ketoglutaric acid (ct-KGA), sorbitan monooleate (Span 80) as the emulsifier and toluene as the oil phase has been studied. The rate of polymerization (Rp) can be represented by: RoocI°5[C]°'5[M]L2S[E]-0"42, where I, C, M and E represent the light intensity (313 nm u.v. light), photoinitiator, monomer and emulsifier, respectively. The kinetic results suggest that the polymerization of acrylamide is essentially a microsuspension one. The emulsifier apparently acts as a retarder. The overall activation energy is 10.20+ 1.58 kJ tool-1. The presence of the gel effect is evident from the increase of molecular weight with conversion and also from the nature of the percentage conversion versus time curves. A useful linear relation between high conversion molecular weight and maximum Rp was found to exist. The relation yields the upper limit of the viscosity average molecular weight [(7.25 ___ 0.48) x 10 6"] for 4.5 mol dm-3 acrylamide, 6.3% (w/v) Span 80, toluene:water = 53:47 (v/v), a stirring rate of 425 rev min- ' and a temperature of 30°C.
Посилання на статтю:
Studies on the kinetics of inverse emulsion polymerization of acrylamide using a-ketoglutaric acid as photoinitiator / Swapan Kumar Ghosh and Broja M. Mandal // Polymer. – 1993. – Vol 34. – P. 4287-4290.