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含羧基磁性高分子微球的合成与表征 总被引:13,自引:0,他引:13
在共沉淀法合成超细磁粉的基础上,以苯乙烯(St)和丙烯酸为共聚单体,以过氧化苯甲酰(BPO)为引发剂,用分散聚合法得到了含羧基的具有核壳结构的磁性高分子微球。采用XRD、TEM、SEM、IR等对样品进行了表征。表征结果表明:制备的磁粉为Fe3O4单相,磁粉的粒径为10 nm左右,微球粒径大约在1~5 μm,呈球形,微球中存在羧基。VSM磁性能测试结果表明:用PEG4000作为表面活性剂时,样品的磁性能最强。分散剂和分散介质对微球形貌和粒度均有影响。 相似文献
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医用高分子材料的生物相容性问题逐步引起人们的重视[1].除合成相容性好的材料外,另一个途径是对现有高分子材料进行改性以提高其生物相容性,其中表面改性因其对材料本体的影响小,成为医用高分子材料研究的一个热点.Ruckenstein[2]最早利用溶液法改... 相似文献
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介绍了能源高分子、催化功能高分子和基于一碳化学的高分子合成等领域的研究动态、进展与尚需关注的重要问题。 相似文献
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用无素分析方法和红外光谱表征季铵盐型功能高分子湿敏材料。用该材料制成的湿敏元件具有优良的湿敏特性,响应时间<10s,恢复时间<15s,但是耐水性不良。 相似文献
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用自由基聚合法合成了大分子单体聚N 乙烯甲酰胺和功能高分子微球 .用GPC、分光光度仪和扫描电子显微镜等对合成的聚合物进行了表征 .研究结果表明 ,大分子单体聚N 乙烯甲酰胺和功能高分子微球具有明显的热敏性特性 ,且合成的功能高分子微球具有单分散性 ,粒径在 1~ 5 μm之间 相似文献
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Narrow- or monodisperse core-shell polymer microspheres with a dense core and a lightly crosslinked shell with different functional groups, such as ester, hydroxyl, cyano, were prepared by two-stage distillation-precipitation polymerization without any stabilizer. Commercial divinylbenzene (DVB), containing 80% of DVB was polymerized by distillation-precipitation polymerization with 2,2′-azobis(2-methyl propionitrile) (AIBN) as initiator in neat acetonitrile in the absence of any stabilizer as the first stage polymerization and used as the core. When the conversion of DVB was about 35% in the first stage, the second-comonomers with different functional groups, such as methyl methacrylate (MMA), ethyl methacrylate (EMA), butyl methacrylate (BMA), 2-hydroxyethyl methacrylate (HEMA), i-octyl acrylate (i-OA), dodecyl acrylate (DA), methyl acrylate (MA), ethyl acrylate (EA), ethylene glycol dimethacrylate (EGDMA), triethyleneglycol dimethacrylate (TEGDMA), trimethylolpropane trimethacrylate (Trim), and acrylnitrile (AN) together with AIBN were introduced, respectively, into the reaction system and copolymerized with unreacted DVB on the core surface to form a lightly crosslinked functional shell. The resulting core-shell polymer particles were characterized with scanning electron microscopy (SEM) and FT-IR spectra. 相似文献
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生物催化剂已被越来越多地用于高分子学中,产生了许多新的反应、工艺和商业用途.酶和全细胞工艺都引起了众多关注,生物催化剂的立体选择性是它们的主要优势之一,新的或改良的方法层出不穷.生物催化的进程主要集中在几个方面上:聚合反应、聚合物修饰反应、聚合物降解反应以及单体和低聚物的合成.在这篇文章中,我们总结了生物催化在高分子合成中的最新应用. 相似文献
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JieHU BaiLingLIU 《中国化学快报》2004,15(4):459-462
The free radical polymerization of styrene in water in the presence of β-cyclodextrin (β-CD) is described.It is found that β-CD could greatly accelerate the polymerization,enhance the final conversion of monomer.The particle-size distribution of the final polymer is also improved than that without β-CD in the system. 相似文献
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以新闻中的化学事件为教学素材, 让学生感受并解析生产、生活中的高分子材料, 落实聚合反应相关基本概念及其规范表达, 使学生认同化学对社会发展的积极意义。 相似文献
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Marc A. Gauthier Dr. Matthew I. Gibson Dr. Harm‐Anton Klok Prof. Dr. 《Angewandte Chemie (International ed. in English)》2009,48(1):48-58
Post‐polymerization modification is based on the direct polymerization or copolymerization of monomers bearing chemoselective handles that are inert towards the polymerization conditions but can be quantitatively converted in a subsequent step into a broad range of other functional groups. The success of this method is based on the excellent conversions achievable under mild conditions, the excellent functional‐group tolerance, and the orthogonality of the post‐polymerization modification reactions. This Review surveys different classes of reactive polymer precursors bearing chemoselective handles and discusses issues related to the preparation of these reactive polymers by direct polymerization of appropriately functionalized monomers as well as the post‐polymerization modification of these precursors into functional polymers. 相似文献
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Stacy Slavin James Burns David M. Haddleton C. Remzi Becer Author vitae 《European Polymer Journal》2011,47(4):435-446
This mini-review describes recent work in the field of glycopolymer synthesis, with a focus on methods that have employed “click chemistry” and controlled polymerization methodology. A variety of carbohydrates with clickable groups such as azide, alkyne, and thiol moieties provide new routes to glycopolymers. Several studies use copper catalyzed azide-alkyne cycloaddition (CuAAC) reactions to synthesize glycomonomers or to incorporate carbohydrates into a clickable polymeric backbone. Alternatively, there are many thiol based click reactions which provide metal-free synthesis, which are discussed in details. 相似文献