分散聚合制备聚苯乙烯/聚氧乙烯两亲聚合物微球

聚乙二醇在NaH的作用下和对氯甲基苯乙烯反应制得聚氧乙烯大分子单体 ,然后在乙醇 /水的介质中通过聚氧乙烯大分子单体和苯乙烯的分散共聚制得粒径范围在 0 5～ 1 5 μm ,粒径分布接近单分散的两亲聚合物微球 .对影响微球粒径和粒径分布的各个因素进行了研究 .     

两亲磁性高分子微球的合成与表征

在Fe3O4磁流体存在下 ,通过苯乙烯与聚氧乙烯大分子单体 (MPEO)分散共聚制备两亲磁性高分子微球 .研究了聚氧乙烯大分子单体对微球粒径的影响 .用扫描电子显微镜 (SEM)、原子力显微镜 (AFM)表征了磁性微球的粒径、表面形貌以及表面粗糙度 ,用傅立叶红外光谱 (FTIR)鉴定了共聚物的结构 .随着聚合物中聚氧乙烯大分子单体含量的增加 ,微球表面的粗糙度增加 ,通过改变共聚物中MPEO的含量 ,可以得到含有 0 4～ 3 5mg g羟值的两亲磁性高分子微球     

分散聚合制备聚苯乙烯/聚氧乙烯两亲磁性高分子微球

采用分散聚合法，以乙醇／水为介质，在Fe3O4磁流体存在下，通过苯乙烯与聚氧乙烯大分子单体共聚制备休磁性高分子微球。 研究了聚合条件对微球粒径的影响。通过改变聚合条件，可以得到平均粒径为5μm-100μm的两亲磁性高分子微球。     

氨基两亲高分子磁性微球的制备与表征

采用分散聚合法,以乙醇水为介质,在Fe3O4磁流体存在下,通过苯乙烯与聚氧乙烯大分子单体(MPEO)共聚制备了同时具有两亲性和磁响应性的端基为氨基的高分子微球.改变聚合条件可以得到平均粒径范围在5～80μm,氨基含量为0.01～0.25mmolg的两亲磁性高分子微球.     

大分子单体聚N-乙烯甲酰胺与苯乙烯共聚合成热敏性功能高分子微球

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     

微波辐射分散聚合制备单分散聚苯乙烯-g-聚氧乙烯微球

传统乳液聚合、悬浮聚合、分散聚合等方法可制备高分子微球,但微球表面吸附的表面活性剂或稳定剂,以及表面缺少功能性基团等原因,导致微球应用受到限制.大分子单体技术在制备单分散功能性高分子微球方面具有许多优势,以致近年来备受国内外学者关注[1].聚氧乙烯PEO大分子单体参与St的分散聚合中,PEO大分子单体可与St形成PSt-g-PEO两亲接技共聚物,制得的PSt-g-PEO两亲共聚物既是产物也是稳定剂.聚合过程中PEO起着稳定分散作用,解决了传统聚合反应中需要添加稳定剂,以及反应完成后脱除稳定剂的麻烦[2,3].通过含功能基团的大分子单体,…     

微米级PS-PEDOT核壳型导电微球的合成与拉曼表征

以分散聚合法制备的微米级聚苯乙烯(PS)微球为模板、3,4-乙烯二氧噻吩(EDOT)为单体、过硫酸铵(APS)为引发剂,通过氧化聚合制备了PS-PEDOT核壳型复合导电微球。采用扫描电镜、透射电镜等对导电微球的形貌和结构进行了表征,重点采用拉曼光谱研究了其核壳结构特征。并研究了超声分散、溶液pH以及单体配比对导电微球形貌的影响。实验结果表明:超声的引入可提高导电微球的单分散性,改善微球的形貌。随着pH的降低或单体配比的增加,导电聚合物在PS微球表面的负载量随之增加,当m(EDOT)/m(PS)由0.60增加到1.25时,导电微球的平均粒径由1.76μm增加到1.91μm。     

分散聚合法制备PVP微球的研究

以N-乙烯基吡咯烷酮(NVP)为初始单体,乙酸乙酯为分散介质,采用分散聚合法制备了分散性能良好、粒径为3～4μm的聚乙烯基吡咯烷酮(PVP)微球.考察了单体、分散剂及引发剂浓度对PVP微球的粒径、单体转化率及分子量的影响,并对PVP的结构和性能进行研究.结果表明,单体浓度增加,PVP微球粒径和分子量增大,单体转化率升高;分散剂浓度增加,PVP微球粒径变小,分子量增大,单体转化率升高;引发剂浓度增加,PVP微球粒径变大,分子量减小,单体转化率升高.与溶液聚合法相比,分散聚合法制备的PVP分子量较小且具有一定的结晶性.     

分散聚合法制备单分散交联聚苯乙烯微球

以苯乙烯为单体、二乙烯基苯为交联剂,通过优化反应条件,制备了平均粒径为3.28～9.04 μm的单分散聚苯乙烯微球和平均粒径为6.60 μm的单分散交联聚苯乙烯微球.探讨了单体浓度、引发剂含量、分散稳定剂用量对微球粒径和分散性的影响.热稳定性分析表明:交联聚苯乙烯微球耐热性明显优于线性聚苯乙烯.     

单分散PS/PAA聚合物微球的研制

以苯乙烯为单体,采用分散聚合法制备了单分散性的聚苯乙烯(PS)微球,然后以PS微球作为种子、丙烯酸(AA)进行无皂种子乳液聚合制备了PS／PAA微球。考察了单体、引发剂、分散剂用量,反应介质极性和交链剂等因素对微球粒径大小及其分布的影响,探讨了分散聚合的反应机理。结果表明,通过改变反应工艺条件,能够制备粒径为1．0～3．0μm、单分散性很好的PS微球;通过无皂种子乳液聚合得到的核壳结构的PS／PAA微球粒径为2．50μm,多分散系数(PI)为0．0325,酸值为10．27mgNaOH／g,其表面带有羧基的特性能进一步扩大应用范围。     

Characterization of Fe3O4/P(St-MPEO) Amphiphilic Magnetic Polymer Microspheres

IntroductionMagnetic microspheres have been widely usedin many fields,such as targetdrug,cell separationand enzyme immunoassay,since the past twentyyears because of their relatively rapid and easymagnetic separation[1] .Although a poly(ethyleneoxide) supported- catalyst system with a solublepolymer as the carrier can easily keep the activityand the selectivity of the catalyst,its recovery hasto be performed by filtration or precipitation fromthe reaction medium,which is time- consuming andener…     

Synthesis of microspheres stabilized sterically with two-component grafted chains by dispersion copolymerizations using mixture of two macromonomers in nonaqueous media

The polymer microspheres were synthesized by dispersion copolymerization of divinylbenzene (DVB) with two vinylbenzyl-terminated poly(ethylene glycol methylether) (PEG)/poly(t-butyl methacrylate) (PBMA) macromonomer blends in methanol. In these systems of two macromonomer blends as the emulsifier, the polymer microspheres formed had a very narrow particle size distribution. Two macromonomers formed comicelles with DVB monomer and acted not only as the comonomer but also as the stabilizer. Such polymer microspheres were stabilized sterically with two-component grafted chains, such as PEG and PBMA, in methanol.     

白蛋白原位复合生物医用功能材料的研究(Ⅰ)──材料的合成和表面结构研究

采用大分子单体技术合成了以聚甲基丙烯酸甲酯为主链,聚氧乙烯链为侧链,末端为白蛋白诱导吸附基团的十八烷基功能聚合物聚甲基丙烯酸甲酯接枝十八烷基聚氧乙烯.采用变角X光电子能谱和表面接触角研究了该功能聚合物在空气和水界面的性质.结果表明,在聚合物-空气界面,十八烷基聚氧乙烯(SPEO)的表面含量随表面层厚度的降低而升高,并在表面发生高度富集.在聚合物-水界面,聚合物表面重组行为较弱,形成了高SPEO含量的疏水表面,该SPEO尾形结构表面预期可发挥聚氧乙烯和十八烷基的协同作用,形成白蛋白原位复合的生物医用功能材料.     

Graft copolymers having hydrophobic backbone and hydrophilic branches. X. Preparation and properties of water-dispersible polyanionic microspheres having poly(methacrylic acid) branches on their surfaces

The free radical copolymerization of poly(t-butyl methacrylate) (PBMA) macromonomer with styrene in ethanol give monodispersed microspheres with 0.8-1.6 μm diameter. The resulting microspheres were treated with HCl solution to convert into anionic microspheres having poly(methacrylic acid) chains. ESCA analysis of the microsphere surface suggested that PBMA chains were favorably located on the surface of the microspheres. The particle size of the microspheres decreased with increasing molecular weight and concentration of the macromonomer. Water dispersibilities of the microspheres were evaluated by measuring the relative turbidity of the suspension of microspheres as a function of pH. The results show that they were strongly dependent on pH. © 1995 John Wiley & Sons, Inc.     

PNVA-g-PSt微球的功能化与离子吸附研究

由大分子单体法合成了表面聚N-乙烯基乙酰胺接枝聚苯乙烯(PNVA-g-PSt)微球,通过对该接枝链进行化学改性得到了新型功能化高分子微球.用透射电子显微镜、激光光散射和X射线光电子能谱对高分子微球的形态、表面组成和直径大小进行了表征,发现微球经水解后形态更加规整,在分散状态下直径有所增加且保持核-壳型结构.实验比较了几种高分子微球对Cu2 ,Pb2 离子的吸附效果.定量测定结果表明:高分子微球经功能化处理后,其吸附效果有了很大的改进,在较低浓度范围,Pb2 离子的脱除率可达100%.     

Preparation of a thermosensitive and biodegradable microgel via polymerization of macromonomers based on diacrylated Pluronic/oligoester copolymers

A novel biodegradable and thermosensitive hydrogel microparticle was prepared via suspension polymerization of a kind of block copolymer macromonomers. According to the molecular design, the macromonomer is composed of a thermosensitive triblock copolymer poly(ethylene oxide)-poly(propylene oxide)-poly(ethylene oxide) (PEO-PPO-PEO) and two oligomers of biodegradable polyester such as oligo(lactic acid) or oligo(ε-caprolactone), and end-capped with acryloyl groups. Microgels were obtained by inverse suspension polymerization of the macromonomer aqueous droplets initiated by a redox initiator. Thermosensitivity and in vitro biodegradation of the resultant microgels were confirmed. The gel microparticles in an aqueous solution were swollen at low temperature and shrunken at high temperature (human body temperature). Degradation rate could be adjusted by controlling the composition and the degree of polymerization of oligoester. Thus, the microgels exhibit combinatory and tunable properties.