【作者】 陈洁；

【导师】 曹堃； 姚臻；

【作者基本信息】 浙江大学 ， 化学工程， 2010， 硕士

【摘要】 本文主要采用RAFT技术制备表面接枝环境敏感性高分子刷的毛发状单分散亚微米级聚合物微球。首先通过无皂乳液聚合法,合成单分散亚微米级聚苯乙烯微球为基质,然后用半连续滴加法在其表面负载RAFT试剂或者光引发剂,再加入功能性单体在紫外光照射下光引发界面聚合。采用该三步法工艺,成功制得温敏性及pH敏感性的环境响应型高分子刷。同时,探讨将表面接枝温敏性高分子刷的微球用于制备具有三维空间有序的胶态晶体膜,考察温敏性高分子刷对其成膜特性的作用及影响。采用RAFT技术制备高分子刷主要包括两部分：将RAFT试剂通过Z基团负载在微球表面,或将RAFT试剂直接添加到连续相中。用RAFT法聚合所得的均聚高分子刷与传统自由基聚合进行比较,考察其毛发厚度、单体转化率、分配系数、产率及分子量的变化,探讨其活性聚合特征,并在此基础上制得嵌段高分子刷。将表面接枝温敏性PNIPA刷的PS微球用于制备具有三维结构的胶态晶体膜。通过改变成膜条件,如PS微球粒径、PNIPA刷厚度及成膜温度等,重点考察了其对成膜三维结构以及光学特性的影响。此外,毛发状微球的制备分别采用了传统自由基聚合法及RAFT试剂负载法,比较了不同制备方法对成膜性能的影响。通过SEM电镜表征了成膜的空间三维结构及粒子排布方式,紫外-可见-近红外反射光谱表征了成膜的光学特性。更多还原

【Abstract】 The Uniform hairy micron-size polystyrene(PS) particles attached with environment-sensitive brushes were prepared by Reversible Addition-Fragmentation Transfer (RAFT) technology with three steps. Firstly, the monodisperse PS particles were prepared by emulsifer-free emulsion polymerization. Secondly, the RAFT agent or photo-initiator were anchored on the surface of the above PS particles using "starve" addition with and without styrene. Finally, functional monomers were added and temperature-responsive and pH-resposive brushes were obtained by UV light-initiated surface polymerization. Furthermore, large scale three-Dimenional(3D) regular colloidal crystals film was prepared to investigate the influence of the temperature-responsive brushes to the morphology of formed film.The preparation of brushes by RAFT technology was achieved by RAFT agent anchored on the surface via Z-group or adding free RAFT agent as the media. Synthesis and comparison of homopolymer brushes bewteen RAFT polymerization and conventional free radical polymerization were discussed, including the change of brush thickness, monomer conversion, partition coefficient, brush yield and molecular weight. All the results showed the characteristics of live/controlled radical polymerization using RAFT technology. In addition, block brushes were synthesized and studied.The preparation of 3-D colloidal crystal films by the PS particles with temperature-responsive PNIPA brushes was discussed. By changing the conditions such as the diameter of PS particles, the thickness of PNIPA brushes, and the temperature, etc. the optics properties of this 3-D structural film were studied. Besides, in order to investigate the RAFT technique in the fields of linearly controlled polymer brushes growth and the colloidal crystal film, comparisons between the traditional polymerization and Z group of the RAFT agent attachment were discussed. SEM characterized the 3-D structures and the arrangements of the particles, and UV-near infrared spectrum indicated the optics properties.更多还原