本文選題：異相聚合 + RAFT聚合�。� 參考：《湘潭大學(xué)》2016年碩士論文

【摘要】：異相體系下的自由基聚合如乳液聚合、分散聚合、懸浮聚合、沉淀聚合等是制備功能性聚合物微球的重要方法。近年來,將可逆加成斷裂鏈轉(zhuǎn)移(RAFT)自由基聚合技術(shù)引入到異相體系中,特別是在大分子RAFT(Macro-RAFT)試劑調(diào)介下的異相RAFT聚合引起了廣泛關(guān)注。這種方法在原位生成嵌段共聚物,并通過聚合誘導(dǎo)自組裝形成聚合物粒子方面顯示了優(yōu)勢。本論文致力于研究異相體系下的RAFT聚合反應(yīng)及其在功能性聚合物粒子制備中的應(yīng)用,先后開展了如下研究工作:(1)無皂乳液RAFT共聚合制備陽離子PS/PMMA膠乳設(shè)計合成一種兩親性聚N-(4-乙烯苯基)-N,N-二正丁基胺鹽酸鹽(PVBAH)Macro-RAFT試劑。以PVBAH作為Macro-RAFT試劑和表面活性劑,研究其調(diào)介苯乙烯與甲基丙烯酸甲酯的無皂乳液RAFT共聚合。分別研究共聚單體組成、乳液固含量、乳化劑濃度及Macro-RAFT試劑分子量對無皂乳液RAFT共聚合的影響。結(jié)果表明,在苯乙烯含量超過30%,乳液固含量低于40%,單體與Macro-RAFT試劑PVBAH的比例小于_(60)0/1及Macro-RAFT試劑PVBAH的分子量在4.7 kg/mol到10.5 kg/mol的條件下,該無皂乳液RAFT共聚合具有較快的聚合反應(yīng)速率和良好的可控性。聚合導(dǎo)致原位生成PVBAH-b-P(St-coMMA)-b-PVBAH嵌段共聚物,并通過聚合誘導(dǎo)組裝形成具有“核-殼”結(jié)構(gòu)的聚合物納米粒子,其中親水鏈段PVBAH形成殼層,疏水鏈段P(St-co-MMA)形成核。合成的嵌段共聚物的分子量與單體轉(zhuǎn)化率呈現(xiàn)線性關(guān)系,且與理論值相近,嵌段共聚物的分子量分布小于1.3。形成的陽離子PS/PMMA膠乳具有較好的穩(wěn)定性,而且聚合物納米粒子的尺寸在24 nm~53 nm可調(diào)控。(2)分散RAFT聚合制備“核-殼-冠”聚合物納米粒子采用“兩步”溶液RAFT聚合方法,分別制備兩種兩嵌段Macro-RAFT試劑,聚(N,N-二甲基丙烯酰胺)-b-聚(3-丙烯酰胺基苯硼酸)(PDMA_(60)-b-PAPBA21-TTC)和聚(N,N-二甲基丙烯酰胺)-b-聚(2,2-二甲基-5-乙基-1,3-二氧六環(huán))丙烯酸甲酯(PDMA_(60)-b-PEDMA25-TTC)。研究PDMA_(60)-b-PAPBA21-TTC和PDMA_(60)-bPEDMA25-TTC兩種Macro-RAFT試劑同時調(diào)介下的苯乙烯分散RAFT聚合。該聚合反應(yīng)具有較好的可控性,并且聚合誘導(dǎo)自組裝形成PDMA_(60)-b-PEDMA25-b-PS/PDMA_(60)-b-PAPBA21-b-PS多組分“核-殼-冠”聚合物納米粒子。其中,疏水性鏈段PS形成“核”,PAPBA和PEDMA鏈段形成“殼”,親水性鏈段PDMA形成“冠”。由于“殼”層中PEDMA鏈段上的縮酮基團在酸性條件下能夠水解成雙羥基基團,并且雙羥基基團與PAPBA鏈段上的苯硼酸基團在p H調(diào)控下能夠發(fā)生動態(tài)交聯(lián),從而制備出動態(tài)殼交聯(lián)多組分“核-殼-冠”聚合物納米粒子。該聚合物納米粒子在生物傳感以及納米載藥系統(tǒng)的設(shè)計中具有廣闊的應(yīng)用前景。
[Abstract]:Radical polymerization in heterogeneous systems such as emulsion polymerization dispersion polymerization suspension polymerization and precipitation polymerization are important methods for preparing functional polymer microspheres. In recent years, the technology of reversible addition chain transfer radical polymerization (RAFT) has been introduced into heterogeneous systems, especially the heterogeneous RAFT polymerization with macromolecular RAFTN Macro-RAFT reagent. This method has shown advantages in in situ formation of block copolymers and in the formation of polymer particles by polymerization induced self-assembly. This thesis is devoted to the study of RAFT polymerization in heterogeneous systems and its application in the preparation of functional polymer particles. The following studies have been carried out in this paper: 1) RAFT copolymerization of soap-free emulsion to cationic PS/PMMA latex has been carried out. An amphiphilic polyN-4 ethylphenylethyl-N- (N-)-di- Ding Ji amine hydrochloride (PVBAHN) Macro-RAFT reagent has been designed and synthesized. The soap-free emulsion RAFT copolymerization of styrene with methyl methacrylate was studied using PVBAH as Macro-RAFT reagent and surfactant. The effects of monomer composition, emulsion solid content, emulsifier concentration and molecular weight of Macro-RAFT reagent on soap-free emulsion RAFT copolymerization were studied. The results show that when the content of styrene is more than 30%, the solid content of emulsion is lower than 40%, the ratio of monomer to PVBAH of Macro-RAFT reagent is less than 60% of the PVBAH and the molecular weight of PVBAH of Macro-RAFT reagent is 4.7 kg/mol to 10.5 kg/mol. The soap-free emulsion RAFT copolymerization has fast polymerization rate and good controllability. Polymerization results in the in-situ formation of PVBAH-b-P(St-coMMA)-b-PVBAH block copolymers and the formation of polymer nanoparticles with "core-shell" structure by polymerization induction, in which the hydrophilic segment PVBAH forms a shell layer and the hydrophobic segment PPVBAH-b-P(St-coMMA)-b-PVBAH St-co-MMA forms the nucleus. The molecular weight of the block copolymers was linearly related to the monomer conversion and was close to the theoretical value. The molecular weight distribution of the block copolymers was less than 1.3. The formed cationic PS/PMMA latex has good stability, and the size of polymer nanoparticles can be controlled at 24 nm~53 nm. (2) dispersed RAFT polymerization is used to prepare "core-shell crown" polymer nanoparticles by "two-step" solution RAFT polymerization. Two kinds of diblock Macro-RAFT reagents were prepared, poly (N- (N-) N-dimethylacrylamide) -b-, poly (3-acrylamido-phenylboric acid), PDMA-60- b-PAPBA21-TTC) and poly (N- (N-N-dimethylacrylamide) -2-dimethyl-2-dimethyl-5-ethyl-1-3-dioxane) methyl acrylate) methyl ester PDMA60- b-PEDMA25-TTCn. The polymerization of styrene dispersive RAFT with PDMA_(60)-b-PAPBA21-TTC and PDMA_(60)-bPEDMA25-TTC Macro-RAFT reagents simultaneously was studied. The polymerization has good controllability, and the polymerization induces self-assembly to form PDMA_(60)-b-PEDMA25-b-PS/PDMA_(60)-b-PAPBA21-b-PS multi-component "core-shell-crown" polymer nanoparticles. The PS of hydrophobic segment formed "nucleus" PAPBA and PEDMA segment to form "shell", and hydrophilic segment PDMA formed "crown". In the "shell" layer, the Ketal group on the PEDMA segment can be hydrolyzed into a dihydroxyl group under acidic conditions, and the dihydroxyl group can be dynamically crosslinked with the phenylboric acid group on the PAPBA segment under the control of pH. Thus, dynamic shell crosslinked multi-component "core-shell-crown" polymer nanoparticles were prepared. The polymer nanoparticles have broad application prospects in biosensor and drug delivery system design.
【學(xué)位授予單位】：湘潭大學(xué)
【學(xué)位級別】：碩士
【學(xué)位授予年份】：2016
【分類號】：O631.5
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本文編號：1833006