• 청정기술
• /
• 제15권1호
• /
• pp.42-46
• /
• 2009

아세틴 촉매상에서 글리세롤(바이오디젤 제조과정의 부산물)과 염화수소 가스로부터 무용매 상태로 디클로로프로판올(DCP)을 직접 제조하는 반응을 기상-액상 회분식 반응기에서 수행하였다. 이를 위해 균일계 아세틴 촉매로 아세틴 혼합물(acetin mixture)과 트리아세틴을 사용하였다. 아세틴 촉매의 활성을 동일한 반응조건($110^{\circ}C$, 3 bar, 3시간)에서 수행된 무촉매 상태에서의 반응성과 비교하였다. 무촉매 반응에 비해 아세틴촉매를 사용한 반응에서 글리세롤의 전환율은 3%정도 증가하였으며 디클로로프로판올의 선택도는 50%가량 증가하였다. 또한 아세틴 혼합물보다는 트리아세틴의 촉매활성이 2% 정도 우수한 것으로 나타났다.

• 한국환경보건학회지
• /
• 제24권3호
• /
• pp.11-17
• /
• 1998

Chitin is known as biodegradable natural polymer. In spite of various application of chitin derivatives from waste marine sources, commercial use of chitin has been limited due to high resistance to chemicals and the absense of proper solvents. We chitin prepared through the decalcification, bleaching and deproteination from Protunus trituberculatus shells by change of Hackman's method. Also, Microcrystalline chitin made by hydrolysis that was reduce made of resistance solvents used by dilute hydrochloric acid, ultrasonic and hydrogen peroxide. Crosslinked chitin derivatives were preparaed from chitin with crosslink agents(epichlorohydrin, 1,3-dichloropropanol) follwed by crosslinkage at 6C position. The effects of these parameters on chitin dervatives were invastigated by IR, DSC, XRD, BET, PSA and SEM. SEM analysis showed that both chitin and crosslinked chitin had a particle shaped morphology.

• Toxicological Research
• /
• 제21권2호
• /
• pp.141-150
• /
• 2005

1,3-Dichloro-2-propanol (1,3-DCP) is known as chloride chemicals and causes severe hepatotoxic agent. The Ito cells and Kupffer's cells of the liver in the 5 old F344 Rats were exposed to 1,3-DCP gas chamber for 6 hours/ a day, 5 days/ a week, and 13 weeks, in the 0, 5, 20, 80 ppm, respectively. After then the body weights, liver weights, and relative liver weight to body weight were measured, and the hepatic tissues were prepared by the routine and Immunostain method, and observed by the LM, and EM. In the results, there were severe body weight decrease (p<0.05) in the 80 ppm of the male and female rats. The relative liver weights to the body weight were increased relate with exposed 1,3-DCP concentration (P<0.001). Inflammatory cells, infiltration was observed at the perivascular area in the 20 ppm exposed group, and bilirubin pigment infiltration, bile duct hyperplasia, inflammation hepatocytic necrosis, fibrosis were observed in the 80 ppm exposure group. In the 80 ppm exposure group, disarrangement of the endothelial cells, erythrocytes and hepatic cell fragment in the Disse space and numerous migration macrophages were observed in the necrotic area by EM observation. In the immunostained hepatic tissues positive stained ED1 cells were extremely increased (P<0.05) in central vein area, but ED2 was weakly positive immunostained in the 80 ppm exposed group. Immunostained desmin was observed in the Ito cell. It was no difference in the low and medium exposed group but it was typical increase in the necrotic area. In conclusion, These results suggest that NOAEL of 1,3-DCP may be 5 ppm in rats and the Immunostained of desmin, ED1 and ED2 positive cells activated in the inflammatory liver were related to the exposure volume and density. The increase of the Ito cells were related to the severe phagocytosis of the Kupffer's cells.

• 한국식품위생안전성학회지
• /
• 제13권1호
• /
• pp.34-40
• /
• 1998

수산계 폐기물로부터 chitin 유도체의 다양한 응용에도 불구하고 chitin 의 상업적 이용은 적절한 용매의 부재와 화학적 제한성으로 인하여 제한적으로 이용되었다. 그러므로 Mima의 방법을 응용하여 NaOH 농도, 반응시간, 온도 등을 조절하여 탈아세틸화반응에 의한 다양한 점도가 다른 chitosan을 제조하였으며, 2종의 각Y제를 이용하여 가교결합에 의한 결정성을 증가시킨 가교 chitosan을 제조하였따. 제조한 점도가 다른 chitosan과 가교 chitosan 유도체를 다양한 분석기기를 이용하여 측정하였다. chitosandmf 제조시 반응시간을 높이거나 반응온도를 높이면 탈아세틸화는 높아지나 분자사슬의 크기, 즉 점도와 분자량은 감소하였다. 반응온도, 반응시간과 알칼리 농도에 따라 활용분야에 맞은 chitosan을 제조할수 있다.