發(fā)布時(shí)間：2018-04-14 23:13

  本文選題：RAFT聚合 + 嵌段共聚物��； 參考：《青島科技大學(xué)》2017年碩士論文

【摘要】：溫敏性兩親嵌段共聚物在水溶液中可以自組裝形成溫敏性膠束,可廣泛應(yīng)用于藥物載釋、萃取分離、酶固定化、分子機(jī)器、組織工程等領(lǐng)域。本文以丙烯酸十八酯(ODA)為疏水單體、N-異丙基丙烯酰胺(NIPAAm)為親水單體,三硫代碳酸酯(TTC)為鏈轉(zhuǎn)移劑,偶氮二異丁腈(AIBN)為引發(fā)劑,通過(guò)可逆加成-斷裂鏈轉(zhuǎn)移聚合法(RAFT)分別合成了一系列溫敏性嵌段共聚物PNIPAAm-b-PODA-b-PNIPAAm(ABA-型)和PODA-b-PNIPAAm-b-PODA(BAB-型)。系統(tǒng)研究了兩種嵌段共聚物在水溶液中的溫敏性和膠束化性能,并利用蘇丹紅為模型藥物初步研究了嵌段聚合物的載藥性能。1、通過(guò)IR和1H NMR對(duì)ABA-型嵌段共聚物的結(jié)構(gòu)進(jìn)行表征,表明成功合成了ABA-型嵌段共聚物。2、ABA-型嵌段共聚物的GPC測(cè)量結(jié)果表明,NIPAAm的含量越大,嵌段共聚物的分子量也越大。嵌段共聚物的聚合度分散指數(shù)(Mw/Mn)始終控制在1.50之內(nèi)(1.3~1.49),說(shuō)明由RAFT法合成的嵌段共聚物的聚合過(guò)程是可控的且分子量分布均勻。3、兩種嵌段共聚物均表現(xiàn)出表面活性,ABA-型嵌段共聚物的CMC值均大于與其親疏水質(zhì)量比相同的BAB-型嵌段共聚物的CMC值。ABA-型嵌段共聚物的親水鏈段越長(zhǎng),CMC值越小;BAB-型嵌段共聚物CMC值變化規(guī)律與ABA-型嵌段共聚物相反,即BAB-型嵌段共聚物的親水鏈段越長(zhǎng),CMC值越大。4、測(cè)得不同嵌段比共聚物膠束溶液的透光率隨溫度的變化,結(jié)果表明兩種嵌段共聚物溶液均表現(xiàn)出良好的雙溫敏性行為,且LCST值隨親水嵌段NIPAAm含量的增加而升高。BAB-型嵌段共聚物比ABA-型嵌段共聚物的第一個(gè)LCST處的透光率下降速率大,第二個(gè)LCST處的透光率下降速率小,且總透光率也比ABA-型嵌段共聚物總透光率下降的少。5、通過(guò)動(dòng)態(tài)光散射法(DLS)測(cè)定不同嵌段共聚物膠束的粒徑及粒徑分布隨溫度的變化,低溫下(小于LCST)ABA-型嵌段共聚物膠束粒徑及粒徑分布PdI為一定值,當(dāng)溫度大于LCST時(shí)ABA-型嵌段共聚物會(huì)發(fā)生團(tuán)聚。而B(niǎo)AB-型嵌段共聚物在溫度高于LCST時(shí)不發(fā)生團(tuán)聚,且BAB-型嵌段共聚物的PdI值較小(小于0.7),粒徑分布均勻。6、兩親性嵌段共聚物膠束核殼結(jié)構(gòu)使得納米粒子具有可以作為疏水性藥物運(yùn)載工具的潛力,負(fù)載藥物(蘇丹紅)后的膠束尺寸明顯增大,表明該藥物被包封到膠束中。
[Abstract]:Temperature-sensitive amphiphilic block copolymers can self-assemble into thermosensitive micelles in aqueous solution and can be widely used in the fields of drug delivery, extraction and separation, enzyme immobilization, molecular machinery, tissue engineering and so on.In this paper, octadecyl acrylate (ODAA) as hydrophobic monomer (N-isopropylacrylamide) as hydrophilic monomer, trithiocarbonate (TTC) as chain transfer agent, azodiisobutyronitrile (AIBN) as initiator,A series of thermo-sensitive block copolymers PNIPAAm-b-PODA-b-PNIPAAmABA- type and PODA-b-PNIPAAm-b-PODA-BAB-type were synthesized by reversible addition-break chain transfer polymerization (RAFT).The thermosensitivity and micellization properties of two block copolymers in aqueous solution were systematically studied. The drug loading properties of block polymers were preliminarily studied by using Sudan as model drug. The structure of ABA- type block copolymers was characterized by IR and 1H NMR.The results of GPC measurement show that the higher the content of niPAAm, the higher the molecular weight of block copolymers.The polymerization degree dispersion index (MW / mn) of block copolymers is kept within 1.50, indicating that the polymerization process of block copolymers synthesized by RAFT method is controllable and the molecular weight distribution is uniform .3. both block copolymers exhibit surface activity.The CMC values of the block copolymers were higher than those of the block copolymers with the same hydrophilic mass ratio. The longer the block segments were, the smaller the CMC values of the block copolymers were. The CMC values of the block copolymers were opposite to those of the block copolymers.That is, the longer the hydrophilic chain segment of Bab-type copolymers is, the larger the CMC value is. 4. The light transmittance of micelle solutions with different block ratios is measured. The results show that both block copolymers exhibit good double-temperature sensitivity.The LCST value increased with the increase of hydrophilic block NIPAAm content. The decrease rate of transmittance in the first LCST of ABA- type block copolymer was higher than that in the first LCST of ABA- type block copolymer, and the decrease rate of light transmittance in the second LCST was lower than that in the first LCST of the ABA- type block copolymer.The total transmittance of the copolymers is also lower than that of ABA- type block copolymers. The particle size and particle size distribution of the micelles of different block copolymers are measured by dynamic light scattering (DLSs).At low temperature (smaller than LCST-ABA- type block copolymer micelle size and particle size distribution PdI is a certain value, ABA- block copolymer agglomerates when temperature is higher than LCST).However, when the temperature of Bab-type block copolymers is higher than LCST, no agglomeration occurs.The PdI value of Bab-type block copolymers is smaller (less than 0.7g, the particle size distribution is even .6. the micelle core-shell structure of amphiphilic block copolymers makes the nanoparticles have the potential to be used as hydrophobic drug delivery vehicles.The micelle size of the loaded drug (Sudan red) increased significantly, indicating that the drug was encapsulated into the micelle.
【學(xué)位授予單位】：青島科技大學(xué)
【學(xué)位級(jí)別】：碩士
【學(xué)位授予年份】：2017
【分類(lèi)號(hào)】：O631

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本文編號(hào)：1751443