Study Of Synthesis And Application Of N-fatty-acyl Chitosan Surfactant

Chitosan, which exists widely in nature, is a natural macromolecular material with good biocompatibility and biodegradability. Acylation modification on chitosan derivatives could give them surface activity, emulsifiability and level-dyeing property. This is in line with the trends of developing ―green‖ surfactants and has broad application prospects.In this paper, fatty-acyl chlorides were used to make acylation to chitosan oligosaccharides and O-hydroxypropylchitosan, two kinds of chitosan surfactants were synthesized: N-fatty-acyl chitosan-oligosaccharides and N-fatty-acyl-Ohydroxypeopylchitosan. An ideal synthetic route was optimized by studying the production rates, dissolubility and surface activity, the structure of the products were determined by FITR and 1HNMR spectrum. Water/pyridine/tetrahydrofuran were used as reaction medium, the volume ratio is 1:2:1; the reaction temperature is 30℃; the reaction time is 1 hour.The surface activity, resistance of acid, alkali and hard water, and other properties were tested. Experimental results show that N-fatty-acyl-chitosan-oligosaccharides can reduce the surface tension effectively, the critical micelle concentration is about 1.7×10-3mol/L, the γcmc is about 40 m N/m, the surface activity of N-fatty-acyl-Ohydroxypropylchitosan is smaller, the critical micelle concentration is about 1.5×10-3mol/L and the γcmc is about 50 m N/m; both of the chitosan surfactants has the ability of emulsifying; N-fatty-acyl-chitosan-oligosaccharides have an excellent resistance of acid and hard water, and a terrible resistance of alkali, while N-fatty-acyl-Ohydroxypropylchitosan have an excellent resistance of acid, alkali and hard water.N-caprylyl-chitosan-oligosaccharide, N-decanoyl-chitosan-oligosaccharide, Ncaprylay-O-hydroxypropylchitosan and N-decanoyl-O-hydroxypeopylchitosan were selected to study the interaction of tracid dyes and the chitosan surfactants. The application of them and their distribution were studied. The experimental results show that the surfactants had an impact on the maximum absorption wavelength and maximum absorbency, which approved that the surfactant had an interaction with tracid dyes. Both of the N-fatty-acyl chitosan surfactants have a good leveling effect, N-caprylyl-chitosanoligosaccharide and N-decanoyl-chitosan-oligosaccharide had an excellent leveling effect when the concentration was 0.2g/L; the transfer rates and fabric dyeing uniformity were improved significantly. N-caprylay-O-hydroxypropylchitosan and N-decanoyl-Ohydroxypeopylchitosan had an excellent leveling effect when the concentration was 0.5g/L; the transfer rates and fabric dyeing uniformity were improved significantly.N-caprylyl-chitosan-oligosaccharide, N-decanoyl-O-hydroxypeopylchitosan, peregal O and ADAEO45 were used to prepare the leveling agent A and B, which were used in the dyeing process of silk and nylon fabric. The experimental results show that both of the leveling agents had a good leveling effect, the leveling agent B had a better effect than A in dyeing the silk and nylon with the same concentration.