Naturally occurring polysaccharides derived from plants are often non-toxic, abundantly available and biodegradable. These properties make them attractive to be used as renewable feedstock for synthesizing various additives including surfactants. However one of the limiting factors in the use of polysaccharides as bio-based surfactants is the high molecular weight, and poor solubility. Molecular weight influences mobility of a surfactant in aqueous phase, thus affecting overall properties including surface activity and cleaning ability. Therefore it was necessary to reduce the molecular weight of these polysaccharides to achieve improvement in properties. This paper describes the synthesis of a novel polysaccharide-based surfactant derived from pectin obtained primarily from citrus peels and apple pomace. The molecular weight of pectin were lowered using chemical and enzymatic methods. A series of pectin-based surfactants in the range of low (3,500-6,000 Dalton), medium (6,000-8,000 Dalton) and high molecular weight (10,000-50,000 Daltons) were hydrophobically modified using long chain alkyl amines.<br/>The effect of molecular weight reduction on surface and interfacial tension of these pectin-based surfactants were studied using the Du Noüy Ring method. The results show that there was a slight reduction in surface tension with lowering molecular weight of pectin, whereas the interfacial tension dramatically decreased for pectin based surfactants in the low and medium molecular weight range. The presence of the hydrophobic groups also improved cleaning ability due to higher wettability of greasy surfaces. Structural and molecular weight characterization, emulsification and stain removal efficiency of these modified polysaccharide-based surfactants will also be presented. This research has unlocked opportunities for non-toxic and bio-derived surfactants from renewable resources.

Effect of molecular weight reduction on surface activity of polysaccharide-based surfactants derived from pectin

251st National Meeting (2016)

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