【作者】 徐俊；

【导师】 倪沛红； 何金林；

【作者基本信息】 苏州大学 ， 化学， 2017， 硕士

【摘要】 多面体齐聚倍半硅氧烷,简称POSS,可以用通式(RSiO1.5)n来表示,是一种纳米尺度上的笼状化合物。由于它具有刚硬的三维立体结构、丰富的表面化学、良好的耐热性和机械性能,已被广泛应用于制备有机/无机杂化材料。本文主要采取活性负离子聚合、开环聚合和点击化学反应,制得了基于POSS的环氧化星形聚合物和两亲性巨型表面活性剂。(一)负离子聚合制备环氧化八臂星形聚异戊二烯经过多年的发展与应用,高真空活性负离子聚合已被科研工作者广泛应用在复杂拓扑结构聚合物的设合成中。在本部分工作中,首先利用仲丁基锂引发异戊二烯进行高真空负离子聚合制备聚异戊二烯基锂(PI-Li)活性链,再与八烯基多面体齐聚倍半硅氧烷(OVPOSS)在环己烷中发生加成反应,一步法制得八臂星形聚合物。利用分级沉淀去除稍过量的线型聚异戊二烯以及低加成产物,即可得到纯的八臂星形聚异戊二烯(8PI-POSS)。最后,通过HCOOH/H202对8PI-POSS中的聚异戊二烯链进行部分氧化反应,获得环氧化八臂星形聚异戊二烯(8EPI-POSS)。利用核磁共振波谱(1H-,13C-NMR)、凝胶渗透色谱(GPC)、傅里叶变换红外光谱(FT-IR)和基质辅助激光解吸电离飞行时间质谱(MALDI-TOF MS)对聚合物的化学结构、分子量及分子量分布进行表征,最后通过热失重分析(TGA)测试聚合物的热分解温度。(二)开环聚合与点击化学反应联用制备巨型表面活性剂巨型表面活性剂(Giant surfactants)是形状类似于小分子表面活性剂的一类特殊结构大分子,由亲水性头基和疏水性高分子尾链组成。在本部分工作中,首先对八乙烯基POSS分子中的双键进行部分氧化并水解生成羟基,通过柱层析法分离得到单羟基七乙烯基POSS(VPOSS-OH);随后,以VPOSS-OH为功能性引发剂在辛酸亚锡催化下引发单体ε-己内酯发生开环聚合,制得七乙烯基POSS功能化聚己内酯(VPOSS-PCL);最后,再利用VPOSS-PCL分别与2-巯基乙醇、3-巯基丙酸和半胱胺盐酸盐与发生thiol-ene点击化学反应,成功地将亲水性端基引入聚合物中,制得三种巨型表面活性剂7HO-POSS-PCL、7HOOC-POSS-PCL和7NH3C1-POSS-PCL。采用NMR、MALDI-TOF MS和GPC表征所合成聚合物的化学结构、分子量及分子量分布,通过TGA测试了聚合物的热分解温度。此外,通过TEM和DLS初步表征了巨型表面活性剂在水溶液中组装形成的纳米粒子形貌和粒径。更多还原

【Abstract】 Polyhedron oligomeric silsesquioxane,which can be abbreviated as POSS and expressed by the general formula(RSiO1.5)n,is a nanoscale cage compound.It has been widely used in the preparation of organic-inorganic hybrid materials because of some characteristics,including rigid three-dimensional structure,rich surface chemistry,good heat resistance and mechanical properties.In this work,two kinds of POSS-based epoxidized star-shaped polymers and amphiphilic giant surfactants are synthesized by living anionic polymerization,ring-opening polymerization and "Click" chemistry.(1)Anionic synthesis and characterization of epoxidized eight-arm star-shaped polyisopreneAfter many years of development and application,high-vacuum living anionic polymerization has been widely used by researchers in the preparation of complex topological polymers.In this part,the living(polyisopryl)lithium(PI-Li)is first synthesized in cyclohexane by high-vacuum living anionic polymerization using sec-butyllithium as the initiator and isoprene as the monomer.Subsequently,PI-Li is used to react with the octavinyl polyhedral oligomeric silsesquioxane(OVPOSS)also in cyclohexane to produce an eight-arm star-shaped polyisoprene(8PI-POSS)in one pot.The purified 8PI-POSS is obtained after fractionation precipitation,and then characterized by nuclear magnetic resonance(1H-and 13C-NMR),gel permeation chromatography(GPC),matrix-assisted laser desorption/ionization time-of-flight(MALDI-TOF)mass spectroscopy and Fourier transform infrared spectroscopy(FT-IR),respectively.Finally,the epoxidized star-shaped polyisoprene(8EPI-POSS)is obtained by the oxidation reaction of 8PI-POSS catalyzed by HCOOH/H2O2.The 8EPI-POSS polymer is also characterized by 1H-and 13C-NMR,GPC and FT-IR analyses,respectively.Moreover,the thermal decomposition temperature of the polymer is measured by thermogravimetric analysis(TGA).(2)Preparation of the giant surfactants by combination of ring-opening polymerization and "Click" chemistryGiant surfactants,which shaped like small-molecule surfactants,is a kind of macromolecule with special structures.It consists of a hydrophilic "head" group and a hydrophobic polymeric "tail" chain.In this part,the double bond in OVPOSS molecule was partially oxidized and hydrolyzed to form one hydroxyl group at first,and the POSS derivative(VPOSS-OH)with one hydroxyl group and seven vinyl groups is isolated by column chromatography;Subsequently,VPOSS-OH is then used to polymerize e-CL under the catalysis of Sn(Oct)2 via ring-opening polymerization,producing polycaprolactone end-capped with heptavinyl POSS(VPOSS-PCL);Finally,VPOSS-PCL is used to respectively react with 2-mercaptoethanol,3-mercaptopropionic acid and cysteamine hydrochloride via UV-induced thiol-ene "click" reaction,resulting in three giant surfactants 7HO-POSS-PCL,7HOOC-POSS-PCL and 7NH3C1-POSS-PCL.The polymers are then characterized by 1H/13C-NMR,GPC and MALDI-TOF mass spectroscopy,and the thermal decomposition temperature are tested by TGA analysis.In addition,the morphology and particle size of nanopaticles formed by the giant surfactants in aqueous solution are preliminary characterized by TEM and DLS analysis.更多还原