Synthesis And Performance Study Of Chitosan Surfactant

The Chitosan is extracted from the shells of shrimps and crabs which are marine solid waste. Chitosan can reduce environmental pollution because of its good biodegradability. Chitosan is natural polymer, which is non-toxic, biodegradable and biocompatible. But its application is limited, due to its poor solubility in water and organic solvent. So that chemical modification of chitosan to generate new biofunctional materials is currently a hot subject of research. The modification would not change the fundamental skeleton of chitosan and it would increase water solubility, keep the original physicochemical and biochemical properties, and bring new or improved properties.In this paper, a new type of water-soluble sulfonic chitosan surfactant was synthesized for the first time. The surfactant was synthesized by the reaction of addition, epoxidation, N-alkylation from epichlorohydrin, sodium bisulfite and chitosan. The structure of the chitosan derivative was affirmed by use of Infrared Absorption Spectra, Ultraviolet Spectrum, Nuclear Magnetic Resonance and Thermal Decomposition. The determination of Critical Micelle Concentration (CMC) of this surfactant was measured by conductivity, hoisting ring and maximum bubble method. The results showed that the new derivative of chitosan presented some surface activity. And the three methods on determination of CMC had little difference, the CMC of the three methods was respectively 2.25 x 10-4 mol·L-1,5.60 x 10-4 mol·L-1,2.50 x 10-4 mol·L-1. Critical Surface Tension is 46 mN·m-1 and 48 mN·m-1 through hoisting ring and maximum bubble method. The results showed that the surfactant presented a certain surface activity. The study provided theoretical guicteline for the future research of sulfonic chitosan surfactant.A kind of quaternary ammonium salt of chitosan surfactant was also designed and synthesized. The graft copolymerization of chitosan and dimethyl diallyl ammonium chloride (DMDAAC), which was initiated by using cerium ammonium nitrate (CAN) as initiator was studied. The structure of the chitosan derivative was affirmed by use of Infrared Absorption Spectra, Ultraviolet Spectrum, Nuclear Magnetic Resonance and Thermal Decomposition. The determination of Critical Micelle Concentration (CMC) and Critical Surface Tension of this surfactant were measured by conductivity, and maximum bubble method. The solubility property, emulsification ability, compatibility, bacteriostasis and moisture-absorption and moisture-retention of product were also studied. The results showed that the CMC of the two methods were respectively 6.80×10-4 mol·L-1 and 8.90×10-4 mol·L-1. Critical Surface Tension was 39 mN·m-1 through maximum bubble method. In addition to anionic surfactant, this product had good compatibility with other types of surfactants. The product showed antibacterial effect to staphylococcus aureus and colon bacillus. What's more, the compound had good hydroscopicity and moisture retentive ability, which was useful for potential development.With cerium ammonium nitrate as an initiator, and with the protection of the nitrogen, the graft copolymerization of dimethyl diallyl ammonium chloride (DMDAAC) and maleic acid on chitosan was studied. The structure characterization was done by Infrared Absorption Spectra, Ultraviolet Spectrum, Nuclear Magnetic Resonance and. Thermal Decomposition. Water-solubility, antibiotic activity, hygroscopicity, moisture retention property and the surface activity of the product were also determined and studied. Results showed that the CMC of the two'methods were respectively 1.85×10-4 mol·L-1 and 2.23×10-4 mol·L-1. Critical Surface Tension is 45 mN·m-1 through hoisting ring method. The generated polymer exhibited good solubility in water, but the longer the storage time was, the worse the solubility was. The product showed no significant effect to staphylococcus aureus and colon bacillus. But the compound had good hydroscopicity and moisture retentive ability.In a word, the performances of quaternary ammonium salt of chitosan surfactant are superior to other modified chitosan surfactants. Therefore, the quaternary ammonium salt of chitosan surfactant has more broad space for development.