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《β羧基丙酸羥丙基甲基纖維素酯的制備與特性研究》由會員上傳分享，免費(fèi)在線閱讀，更多相關(guān)內(nèi)容在學(xué)術(shù)論文-天天文庫。
1、摘要羥丙基甲基纖維素(腫MC)的熱凝膠轉(zhuǎn)變主要緣于體系中對溫度非常敏感的分子間或鏈段間的締合或組裝。本工作通過酸酐對HPMC進(jìn)行酰化制備了D．羧基丙酸羥丙基甲基纖維素酯和6．羧基丙酸醋酸羥丙基甲基纖維素酯，并重點(diǎn)對其凝膠轉(zhuǎn)變和特性進(jìn)行了研究。采用丁二酸酐和醋酸酐為酯化劑、無水醋酸鈉為催化劑與HPMC通過酯化反應(yīng)在冰醋酸溶劑中制備了一系列合成產(chǎn)物，即B．羧基丙酸羥丙基甲基纖維素酯([3-CPHPMC)和p．羧基丙酸醋酸羥丙基甲基纖維素酯(p-CPAHPMC)。采用電導(dǎo)率滴定法測定了產(chǎn)物中的D．羧基丙酰基的含量；采用FT-IR紅外光譜
2、、粘度分析和流變儀等方法對其結(jié)構(gòu)和性能進(jìn)行了表征。結(jié)果表明：平均每個(gè)D．羧基丙酸羥丙基甲基纖維素酯分子鏈上D．羧基丙酰基的含量為2．9～12．42；1wt％13．CPHPMC溶液的凝膠溫度從56．65℃降至41．9℃，而1叭％HPMC溶液的凝膠溫度為59．85℃；6．羧基丙?；暮吭蕉啵?3-CPHPMC凝膠溫度越低；凝膠強(qiáng)度也隨著增大；與13-cP唧Mc相比，[3-CPAHPMC由于引入乙?；淠z強(qiáng)度大大增加。關(guān)鍵詞：羥丙基甲基纖維素；熱凝膠；D．羧基丙酸羥丙基甲基纖維素酯；p．羧基丙酸醋酸羥丙基甲基纖維素酯；丁二酸酐；醋
3、酸酐；凝膠溫度；凝膠強(qiáng)度；締合；組裝ABSTRACTThethermoreversiblegelationofhydroxypropyImethylcellulose(HPMC)isgeneratedmainlyduetothetemperature．sensitiveintermolecularassociationorassembly．Inthiswork，hydroxypropylmethylcellulosederivativeswerepreparedbvesterificationwithacidanhydride，w
4、hichwereinvestigated，layingastrongemphasisontheirthermogelationandproperties．Therefore，twoseriesofhydroxypropylnlethylcellulosederivatives，whichare13-carboxypropionatehydroxypropylmethylcellulose(13-CPHPMC)andp’carboxypropionateacetatehydroxypropylmethylcellulose(13．C
5、PAHPMClweresynthesizedfromhydroxypropylmethylcellulose(HPMC)byesterificationusingSUCClnlCanhydrideand／oraceticanhydrideasesterifyingagent，anhydroussodiumacetateascatalystandaceticacidasorganicsolvent．Thecontentof13-carboxypropionylgroupin13-CPHPMCwasdeterminedbyconduc
6、tometrictitfation．Thestructureandpropertiesof13-CPI-IPMCwereanalyzedbyFT-Rviscometerandrheometer．Theresultshowedthatthenumberof13-carboxypropionylgroupspercellulosicmacromolecularchainwasfrom2．9t012．42andthegelationtemperatureof1％byweight／3-CPHPMCsolutionsrangedfrom56
7、．65。Cto41．9"C．whereasthatofalwt％HPMCsolutionwas59．85V，thatwithallincreaseintheCO力tentof13-carboxypropionylgroups，thegelationtemperatureof13-CPI-IPMCdecreasesbutitsgelstrengthIncreasesandthatincomparisonwithI]-CPI-tPMC，thegelstrengthof[3-CPAHPMCisconsiderablyhighbecaus
8、eofacetylgroupsonitsmoIecularchains．KEYWORDS：hydroxypropylmethylcellulose，thermoreversiblegelation，13-carboxypropionatehydro
