羧甲基壳聚糖的合成分析研究 化学工程与工艺专业VIP免费

摘要壳聚糖(chitosan,CTS)作为一种至关重要的大分子有机化合物，被广泛应用于化工、医疗、食品制造等各个行业。但是由于壳聚糖性质特殊，除酸外，不溶于水性溶剂，且CTS在浓酸当中还会水解，因此它的实践用途并非十分广泛。故对壳聚糖进行结构修饰，极大程度地改变其溶解性能。本课题以壳聚糖为原料，在碱性条件下，用氯乙酸对壳聚糖进行化学改性研究，合成具有良好水溶性的羧甲基壳聚糖。其次考察合成条件如反应温度、时间、氯乙酸质量对合成羧甲基壳聚糖的取代度的影响情况。同时也用红外光谱的分析方法测定产物结构及取代度。实验结果表明，反应1h到反应3h间，产品的羧甲基取代度一直增加；反应40℃到反应60℃间，产品的羧甲基取代度先增加再减少；氯乙酸质量从2.0g加到2.8g，产品的羧甲基取代度先增加再减少。结论：取反应时间为2小时，反应温度为50℃，氯乙酸质量为2.4g,可以得到取代度较高的羧甲基壳聚糖。关键词：壳聚糖；氯乙酸法；取代度；羧甲基壳聚糖ABSTRACTChitosan(CTS),asanimportantmacromoleculeorganiccompound,iswidelyusedinchemicalindustry,medicaltreatment,foodmanufacturingandotherindustries.Butbecauseofitsspecialproperties,besidesacid,itisinsolubleinwater-bornesolvents,andCTScanhydrolyzeinconcentratedacid,soitspracticaluseisnotveryextensive.Therefore,thestructuremodificationofchitosancangreatlychangeitssolubility.Inthispaper,chitosanwasusedasrawmaterialtosynthesizecarboxymethylchitosanwithgoodwatersolubilitybychemicalmodificationofchitosanwithchloroaceticacidunderalkalineconditions.Secondly,theeffectsofsynthesisconditionssuchasreactiontemperature,timeandqualityofchloroaceticacidonthedegreeofsubstitutionofcarboxymethylchitosanwereinvestigated.Thestructureanddegreeofsubstitutionoftheproductwerealsodeterminedbyinfraredspectroscopy.Theresultsshowthatthedegreeofcarboxymethylsubstitutionoftheproductincreasesfrom1hto3h,increasesfirstandthendecreasesfrom40to60andthedegreeofcarboxymethylsubstitutionoftheproductincreasesfirstandthendecreaseswhenthemassofchloroaceticacidincreasesfrom2.0gto2.8G.CONCLUSION:Carboxymethylchitosanwithhighdegreeofsubstitutioncanbeobtainedwithreactiontimeof2hours,reactiontemperatureof50Candmassofchloroaceticacidof2.4G.Keywords:chitosan;chloroaceticacidmethod;degreeofsubstitution;carboxymethylchitosan目录摘要.............................................................................................................................IABSTRACT..................................................................................................................II1．绪论..........................................................................................................................11.1课题背景与意义...............................................................................................11.2壳聚糖的相关反应...........................................................................................11.3羧甲基壳聚糖的应用与发展...........................................................................21.4本文研究的内容...............................................................................................42．实验部分..................................................................................................................52.1实验试剂与实验设备.......................................................................................52.2羧甲基壳聚糖的制备.......................................................................................62.3羧甲基壳聚糖取代度（DS）的测定................................