一锅链增长—逐步增长点击分散聚合制备软—硬功能补丁粒子

发布时间：2018-05-27 06:03

本文选题：补丁粒子 + 点击聚合　；参考：《北京化工大学》2017年硕士论文

【摘要】：补丁粒子指具有一或多个不同化学或物理特性区域的粒子,补丁间或补丁与其他物质间具有定向相互作用,使补丁粒子具有很多特殊功能和应用,如用作多级结构材料构件、固体表面活性剂、药物载体和传感器等。目前,已发展出许多制备补丁粒子的方法。其中,种子溶胀-聚合相分离(种子相分离)法是应用较为广泛的一种方法,能够大量制备补丁粒子,且粒子形貌易于调控。然而,该法涉及步骤较多,且补丁粒子各区域功能化较困难。本课题组将分散聚合过程中的增长粒子作为动态变化的种子,发展了一锅(两步、一步加料)分散聚合制备补丁粒子的方法,结合点击反应,可调控补丁粒子新生成部分的形貌、结构和组成,但没有对该过程进行系统研究。通常利用传统自由基链增长聚合制备球形粒子及补丁粒子,最近几年开始利用非均相逐步点击聚合直接制备球形粒子,该法具有聚合条件温和、粒子易于功能化等优点,但是所得粒子的Tg较低,且未涉及非球形或补丁粒子的制备。本论文在一锅苯乙烯链增长分散聚合过程中结合巯基-烯逐步点击聚合,制备形貌、结构和组成可调控的补丁粒子,并探讨所得粒子的功能化及应用。论文主要工作如下:1.以甲醇/水(MeOH/H2O=6/4)混合液为分散介质,单体为苯乙烯(St)、苯乙烯磺酸钠(NaSS),引发剂为偶氮二异丁腈(AIBN)进行分散聚合。过程中加入巯基-烯点击单体聚合,获得了含有硬核(PSt,Tg较高)及软壳层、单或多孔、单或多凸起(点击聚合物,Tg较低)的粒子。探讨了点击单体加入时间、用量、配比及单体种类等对粒子形貌、结构和组成的影响;2.通过SEM和TEM观察、凝胶含量和转化率测定及FTIR分析,考察了加入点击试剂后粒子形貌、组成的演变过程及聚合行为。确定了补丁粒子的形成机理:PSt与点击聚合物的Tg及亲水性不同,导致分相、形成补丁粒子;等摩尔巯基-烯投料,发生非等摩尔反应,得到含过量-C=C-或-SH功能粒子;3.对补丁粒子不同区域进行了选择功能化:利用PSt核表面-SO3-负载磁性粒子,利用补丁处-SH吸附Ag纳米粒子,利用补丁处-SH或-C=C-与功能单体点击反应,得到荧光标记补丁粒子、超疏水/亲水粒子,进一步获得了超疏水/亲水粒子膜。
[Abstract]:Patch particles are particles having one or more different regions of chemical or physical properties, and patches or patches have directional interactions with other substances, enabling patch particles to have many special functions and applications, such as being used as multilevel structural material components, Solid surfactants, drug carriers, sensors, etc. At present, many methods of preparing patch particles have been developed. Among them, seed swelling and polymeric phase separation (seed phase separation) is a widely used method, which can prepare patch particles in large quantities, and the morphology of the particles is easy to control. However, there are many steps involved in the method, and it is difficult to functionalize each region of patch particles. Our group developed a one-pot (two-step, one-step) dispersion polymerization method to prepare patch particles by using the growing particles in the dispersion polymerization process as seeds of dynamic change. The morphology, structure and composition of the newly formed part of the patch particles can be regulated, but no systematic study has been carried out on the process. Spherical particles and patched particles are usually prepared by traditional free radical chain growth polymerization. In recent years, spherical particles have been prepared directly by heterogeneous step by step click polymerization. This method has the advantages of mild polymerization conditions and easy functionalization of particles. However, the TG of the obtained particles is relatively low and does not involve the preparation of non spherical or patch particles. In this paper, in the process of one-pot styrene chain increasing dispersion polymerization, mercapto-alkene polymerization was combined step by step to prepare patched particles with adjustable morphology, structure and composition, and the functionalization and application of the resulting particles were discussed. The main work of this paper is as follows: 1. The dispersion polymerization was carried out with methanol / water / MeOH / H 2O 6 / 4 mixed solution as dispersion medium, monomer as styrene stout, sodium styrenesulfonate as sodium sulfonate and initiator as azodiisobutyronitrile (AIBN). In the process of mercapto-ene-click monomer polymerization, particles containing high hard core PSt-Tg and soft shell layer, single or porous, single or multiple protrusions (low TG of click-polymer) were obtained. The effects of click-monomer addition time, dosage, ratio and monomer type on particle morphology, structure and composition were discussed. The particle morphology, composition evolution and polymerization behavior were investigated by SEM and TEM, gel content and conversion and FTIR analysis. It was determined that the formation mechanism of patch particles was different from that of click-polymer and TG and hydrophilicity, which resulted in phase separation and formation of patch particles. Different regions of patch particles were selected and functionalized. Using magnetic particles loaded on the surface of PSt nucleus, adsorption of Ag nanoparticles by patch site -SH, click-to-click reaction between patch site and functional monomer, fluorescent labeled patch particles were obtained. Superhydrophobic / hydrophilic particle membranes were further obtained.
【学位授予单位】：北京化工大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：O631.5

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