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1、中文摘要為了改善殼聚糖的溶解性,本文對聚乙二醇單甲醚(MePEG)接枝改性殼聚糖進(jìn)行了研究。首先,通過官能團(tuán)偶聯(lián)反應(yīng),將端基改性為醛基的聚乙二醇單甲醚接枝到殼聚糖分子鏈上,制得了梳狀、可溶于水的聚乙二醇單甲醚接枝殼累糖(CTS.g.MePEG)。采用元素分析、紅外光譜和透射電鏡等方法對產(chǎn)物的結(jié)構(gòu)和性質(zhì)進(jìn)行了表征。研究表明,所制得的CTS—g—MePEG在水溶液中能夠自鲴裝成皎束,且在酸性溶液中表現(xiàn)出有別于殼聚糖的流變性。采用上述方法,本文還制備了可以在更廣泛的pH值范圍內(nèi)分散的聚乙二醇單甲醚接枝羧甲基殼聚糖(CMCTS.g.MePEG),并對其流變性、兩性聚電解質(zhì)
2、性質(zhì)及其與水溶性殼聚糖的復(fù)合行為進(jìn)行了研究。為了保留殼聚糖上的氨基,本論文探索了另一種接枝改性殼聚糖的途徑,即用鄰苯二甲酸酐對殼聚糖上的氨基進(jìn)行保護(hù),然后用甲苯二異氰酸酯為偶聯(lián)劑將聚乙二醇單甲醚接枝到殼聚糖大分子鏈上,最后用水合聯(lián)氨為還原劑解除對氨基的保護(hù)。實驗結(jié)果表明,該方法可以使氨基得到保護(hù),并能把聚乙二醇單甲醚接枝到殼聚糖上,但水合聯(lián)氨在脫保護(hù)氨基的同時也還原了接枝鏈上的氨酯鍵,導(dǎo)致了聚乙二醇單甲醚的去接枝化。關(guān)鍵詞:殼聚糖;羧甲基殼聚糖;聚乙二醇單甲醚;接技反應(yīng)ABSTRACTInordertoimprovethepoorsolubilityofchito
3、san,monomethoxypoly(ethylerieglyc01)graftedchitosan(CTS—g—MePEGlwel℃preparedbythereactingofaldehydedmonomethoxypoly(ethylene91yc01)andthe2-aminofunctionsofchitosan.Theobtainedcomb·-shapedCTS—g-MePEGproductspresentgoodwatersolubility.Elementalanalysis、IRspectroscopyandTEMmeth,:.dswereu
4、sed:oestimatethepropertiesofthegraftedproducts.ThercsnksindicatethatihepreparedCTS·g-MePEGCallself-assembleintomieellesindistilledwatersolution.Moreove0thegraftedchitosanpresentsdifferentrheologicalpropertyfromchitosaninacidicmedium.Usingthesamemethod,thepresentpaperalsopreparedmonome
5、thoxypoly(ethyleneglyc01)gaffedcarboxymethylchitosan(CMCTS·g—MePEG),whichCanbedispersedinwateroverallpHrange.Therheologicalproperty,amphotericpolyelectrolytepropertyandthecomplexingbehaviorofCMCTSandCMCTS—g—MePEGwithwater-solublechitosanwereinvestigated.Inordertoremainthefreeaminogrou
6、psonchitosan,chitosan-0一monomethoxypoly(ethyleneglyc01)WaspreparedbythegraftingofMePEG—NCOtothehydroxylgroupsofN·phthaloylchitosan.Thephthaloylgroupswereremovedwitllhydrazinemonohydratetoregeneratethefreeaminogroups.Theresultsshowedthattheaminogroupscallbeprotectedbyphthalicanhydridea
7、ndMePEGcallbegraftedontoCTSatthehydroxylgroups.Butunfortunately,thehydroxylgroupswerepartlydeoxidisedduringtheprocessofdeoxidizingphthaloylgroupsbyhydrazinemonohydrate.Keywords:chitosan,carboxymethylehitosan,monomethoxypoly(ethyleneglyc01),graftingreaction獨創(chuàng)性聲明本人聲明所里交的學(xué)位論文是本人在導(dǎo)師指導(dǎo)下進(jìn)行的
8、研究工作和