N-Stearoyl chitosan was prepared to investigate the film properties as semipermeable membrane. N-Stearoyl chitosan was synthesized by the stearoylation of chitosan which was from chitin by deacetylation with alkali. Thus prepared chitosan sample had 87% of total possible acetylamino group deacetylated. Extent of N-stearoylation was 17%. This sample of N-stearoyl chitosan was soluble in formic acid and water-swelling films could be cast from formic acid solution. Thus prepared films had wet thickness, 18-22μ, and dry thickness, 12-13μ, indicating 15.8% wafter absorption. Presently prepared N-stearoyl chitosan film had exclusion limit around 4,000 molecular weight, this value is in contrast with chitin (10,000) and acetyl chitin (7,500). Polyethylene glycols had larger rejection efficiency than amino acids and saccharide toward solutes of similar molecular weight. This correlates well with the distribution coefficient for the various solutes. The flux through the membranes was characterized in terms of convective and diffusive flow, and found to be the combination of both types of flow.

N-Stearoyl chitosan을 한외여과 막으로서 성질을 조사하기 위해 키토산을 N-stear-oylation하여 합성하였다. 키토산의 아민기중 평균 6개중 하나에 stearoylation 반응이 일어났으며 합성한 막을 포름산에 녹여 필름을 제조한 결과 막의 두께는 18-22μ, 함수율은 15.8%이었다. 얻어진 필름으로 rejection efficiency (RE)를 측정한 결과를 키틴, 아세틸 키틴과 비교하였다. Exclusion limit가 분자량 4,000으로 키틴보다 매우 적은 값이며 분자량이 증가함에 따라 증가하였다. 또한 키틴 unit의 알콜기가 모두 존재하고 long chain alkyl기에 의한 소수성을 동시에 가지고 있어 아세틸 키틴보다 친수적 용질에 대해 RE가 작게 나타나고 있다. 그리고 아미노산의 경우 L과 D form 이 막에 대한 투과성이 같았으며 saccharide류가 polyethylene glycol류 보다 RE가 작은 이유를 분배계수로서 설명하였다. 또한 농도와 압력에 따른 RE의 변화추세를 검토하고 막에 대한 flow를 convective와 diffusive flow로 나누어 고찰하였다.

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