NOVEL NONIONIC OLIGOSACCHARIDE SURFACTANT POLYMERS DERIVED FROM POLY(VINYLAMINE) WITH PENDANT DEXTRAN AND HEXANOYL GROUPS

A series of novel surfactant polymers: poly(N-vinyldextran aldonamide- co-N-vinylhexanamide) (PNVDA-co-PNVH), in which hydrophilic dextran ol igosaccharides and hydrophobic hexanoyl groups were incorporated simul taneously on to poly(vinylamine) (PVAm), were synthesized, and charact erized by FTIR and H-1 NMR spectroscopy. Structurally well-defined pol y(vinylamine) was prepared by hydrolysis of poly(N-vinylformamide), wh ich was obtained by free radical polymerization of N-vinylformamide. D extran molecules (M-w = 1600) were attached to poly(vinylamine) by rea cting amine groups with dextran lactone, while hexanoyl groups were at tached by reacting amine groups with N-(hexanoyloxy)succinimide. By ad justment of the feed ratio, surfactant polymers with different hydroph ilic/hydrophobic balances were prepared. Surface activity of the surfa ctants at an air/water interface was demonstrated by significant reduc tions in water surface tension. Surface activity at a solid surface/wa ter interface was demonstrated by atomic force microscopy of surfactan t molecules adsorbed onto a highly oriented pyrolytic graphite. The sy nthetic approach described in this report provides a route to prepare a variety of oligosaccharide surfactant polymers with well-defined str uctures and hydrophilic/hydrophobic balances, by selecting different c ombinations of oligosaccharide and alkanoyl groups or by adjusting fee d ratio of the oligosaccharide to alkanoyl groups.