Abstract
The viscometric behavior on the interaction of poly (vinyl alcohol) (PVA) with sodium 2-sulfonatofatty acid methyl esters [abbr. SFM, CnH2n+1CH (SO3Na) COOCH3 ; n=12 : STM and n=14 : SHM] in aqueous solution was investigated in the absence and in the presence of urea. The formation of a polyelectrolytelike complex between PVA and the SFM was confirmed from the viscosity change with the concentration of surfactant. At high concentration of surfactant above cmc, the intrinsic viscosity [η] of PVA-STM solution was smaller than that of PVA-sodium dodecyl sulfate (SDS) solution. This suggests that the PVA-STM complex in aqueous solution may be existed in more contracted molecule than the PVA-SDS complex. Also it was suggested that the formation of the PVA-SFM complex may possibly be attributed to the van der Waals' force between PVA and the surfactant and in addition, the intramolecular hydrogen bond of complex molecule between a carbonyl group of bound SFM on PVA and a long range hydroxyl group of PVA chain. The [η] CS (CS : surfactant concentration) curve for STM showed that the value of [η] increased with increasing amount of STM in the region of cmc around to 10-2M and it was depressed above 10-2M. At the concentration of surfactant above 10-2M, the degree of a drop in [η] of PVA-STM complex with the concentration of urea was much smaller than that of PVA-SDS complex.
