갑각류 외피의 유효이용을 위한 Chitin 및 Chitosan의 제조와 물성학적 특성에 관한 연구 -1. Chitosan의 분자량과 탈아세틸화도에 미치는 제조조건의 영향- = Preparation and Rheological Properties of Chitin and Chitosan -1. Effect of preparation condition on the degree of deacetylation and the molecular weight of chitosan-

다국어 초록 (Multilingual Abstract)

Chitosan was prepared from red snow crab (Chinonecetes japonicus) under various conditions of deacetylation (NaOH concentration, heating temperature, heating time and intermittent and repetition treatment). By measuring the degree of deacetylation and the molecular weight (Mw), effect of preparation condition was studied. As the concentration of NaOH increased in deacetylation process, for chitosan treated over $40\%$ NaOH, the rate of increase of the deacetylation of chitosan decreased, but the difference of Mw decrease was nearly constant. When treatment temperature increased from $130^{\circ}C$ to $150^{\circ}C$, the deacetylation degree increased only $3^{\circ}C\;from\;84\%\;to\;87\%,$ but Mw decreased from 267,000 to 85,800. The difference of Mw decrease of chitosan treated $130-150^{\circ}C$ was larger than that with $90-130^{\circ}C$. The deacetylation degree and Mw of the chitosan prepared by continuous treatment for 3 hrs was$84\%$ and 267,000. On the other hand those of chitosan with intermittent and repetition treatment for 3hrs was $93\%$ and 28,000. In order to increase the degree of deacetylation and inhibit depolymerizing, the intermittent and repetition treatment was found to be more effective than the continuous treatment.