Photosensitive Modification And Application Of Chitosan

CTS-HS was synthesized through amidation reaction between chitosan andmercaptoacetic acid with EDC/NHS as catalyst. AIBN as initiator, photosensitive monomerCEMA and hydrophilic monomer MPEG as co-polymeric monomers, CTS-HS as chainstransfer agent, the final chitosan photosensitive graft copolymer CTS-g-P(CEMA-co-MPEG)was obtained by the free radical polymerization, and its chemical structure was characterizedby FT-IR. CTS-g-P(CEMA-co-MPEG) automatically assembled micelles in water, theproperties of micelles were studied by UV-Vis spectroscopy, Zeta potential analyzer,nano-particle size analyzer and TEM. The emulsifying properties ofCTS-g-P(CEMA-co-MPEG) with white mineral oil as the oil phase were studied. The resultsshowed that CTS-g-P(CEMA-co-MPEG) could self-assemble into spherical micelles about120nm in water, this micelles have good photosensitivity and emulsification property.Another photosensitive graft copolymer CTS-g-HAB was obtained by the free radicalpolymerization also using the photosensitive monomer HAB as a grafting monomer, AIBN asan initiator and CTS-HS as a chains transfer agent. This new copolymer could self-assembleinto spherical micelles, and able to absorb a wider wavelength range of ultraviolet(UVA andUVB).Methane sulfonic acid as solvent, CTS-g-CICH was obtained from the reaction ofChitosan and cinnamon chloride under ice bath, its chemical structure was characterized byFT-IR and1HNMR. CTS-g-CICH could self-assemble micelles in water, the influence ofultraviolet ray, pH value and ion concentration on micelles solution were studied by UV-Visspectroscopy, Zeta potential analyzer, nano-particle size analyzer, using TEM characterize themorphology of micelles. Results showed that micelles were able to form uniform sphericalmicelles in water with good stability. Preparing pickering emulsion using CTS-g-CICHmicelles as an emulsifier, the influence of micelle concentration, pH value, salt concentration,oil type and oil/water ratio on emulsion were studied, results showed that the micellarparticles of this system have good emulsifying properties, is expected to used as sunscreenand emulsifier in cosmetics.With the natural macromolecules of γPGA for materials, a new graft polymer PGA-g-L-Phe was synthesized. The differences of particle size, Zeta potential, TEM betweenmicelles with different NaCl concentrations were researched. The results showed that, themicelles with0.05mol/L NaCl solution have a better stability. The influence of pH value,oil phase type, oil/water ratio on emulsion were explored preliminarily. PGA-g-L-Phe hasgood emulsifying properity, plus the highly moisturizing of γPGA, PGA-g-L-Phe is expectedto become the next generation of moisturizing ingredients and will play an increasinglyimportant role in cosmetics in the future.