Study On Preparation Of Chitooligosaccharide By Photocatalysis And Cellulase

Chitosan is an environmental friendly crude macromolecule material. It is made from Chitin by deacylation that is distributed widely in nature. Chitooligosaccharide that is the degradation product of chitosan has many excellent capabilities. In this paper, the degradation condition of chitosan has been studied by photocatalysis and cellulase degradation. The following research work has mainly been done in the subject.There are hardly any reports about photocatalysis degradation of chitosan. In this paper, it has been firstly studied in details. The experiment showed that chitosan can be degraded none but photocatalyst and ultraviolet radiation were occured at the same time. The relative molecular weight of degradation product decreased with the ultraviolet radiation irradiated time prolonged, catalyzer dimension reduced and amount added. Furthermore, catalyzer genre, lamp-house and pH can also have the influence. Adding a little of H₂O₂ was in favor of creating hydroxyl that can enhance the effect of photocatalysis degradation reaction. However, superfluous H₂O₂ can decrease hydroxyl.Cellulase has obvious degradation action of chitosan. The influencing factors on the degradation reaction, including reaction time, pH, temperature and cellulase amount, were studied in details. The results obtained indicated that: the relative molecular weight of degradation product decreased markedly with the reaction time, temperature and cellulase amount increased. Different factors have different influencing degree. There was a sequence as following: pH >temperature > time > cellulase amount. The best degradation condition of chitosan by cellulase that was given from the experiment results is: the pH is 5.0, the temperature is 50°C,the time is 5h,the cellulase amount is 12%.