相分离聚合法:(Ⅱ)二乙氨基乙基型共聚功能微球的合成

<正> 随着生物工程高技术的发展,功能高分子微球作为一类新的功能高分子材料已得到十分广泛的应用。然而关于最难以合成的粒径在微米级、粒度分布窄的高分子微球合成的报道至今仍很少。本文报道了用相分离法(即静止的分散聚合法)合成含有DEAE基团的高分子微球的研究。探讨了单体、交联剂、引发剂及聚合温度、聚合时间等聚合条件对生成微球的影响。相分离聚合法的特点是利用了随着在聚合过程中单体的逐渐聚合,分子量长大,聚合体与反应体系间相容性变差而最终分相成球的原理,因而所形成的微球粒度圆,粒径比较均一。与一般的分散聚合法相比不仅生成微球的粒径较大,且不需要搅拌,使反应装置得以简化。     

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     

微波合成均分散高分子微球及其机理

微米级大粒径单分散高分子微球在标准计量、情报信息、分析化学等许多领域都有广泛的应用前景［１］,在临床检验和诊断、免疫技术、细胞学研究以及血液循环等生物医学领域也发挥了极大作用［２］．在微球的各种特性中,影响其应用的重要因素是微球的尺寸、分散性及形态等,因此对微球的尺寸和均匀性的控制就显得十分重要,对其形成机理的研究也很有意义,对此已有许多实验和理论的报导［３－６］．在微波辐射条件下,采取种子聚合法合成高分子微球,可以得到不同尺寸的粒子,并且有很好的分散性,比普通加热条件下反应时间大大缩短,所得数…     

热敏性聚(N-乙烯基异丁酰胺)接枝高分子微球的合成

用自由基聚合和端基反应法合成了大分子单体聚 (N 乙烯基异丁酰胺 ) (PNVIBA) ,将其与苯乙烯在乙醇 水的混合溶剂中进行分散共聚 ,得到了PNVIBA接枝聚苯乙烯 (PNVIBA g PSt)高分子微球 .用GPC、激光光散射和电子显微镜等对聚合物的分子量和微球直径及形态进行了表征 .研究结果表明 ,大分子单体PNVIBA和PNVIBA g PSt高分子微球具有明显的热敏性 ,并且发现PNVIBA g PSt微球直径和形态可通过改变反应条件加以控制 ,得到了一种新形态的亚微米级高分子微球     

超顺磁性高分子微球的制备与表征

用化学共沉淀方法制备了Fe3O4纳米微粒,并用油酸(十八烯酸)和十二烷基苯磺酸钠为双层表面活性剂进行表面修饰,制备了稳定的水分散性纳米Fe3O4可聚合磁流体.在Fe3O4磁流体存在下,将苯乙烯与甲基丙烯酸通过乳液聚合方法制备了磁性高分子微球.透射电镜研究表明,Fe3O4微粒的平均粒径在10nm左右,乳液聚合形成的磁性高分子微球的粒径平均约为130nm;用超导量子干涉仪对微粒及高分子微球进行了磁性表征,结果表明,合成的Fe3O4纳米微粒以及磁性高分子微球均具有超顺磁性.同时,还用红外光谱及X射线衍射表征了磁性高分子微球的化学成分和晶体结构.用热失重方法测得磁性高分子微球中磁性物质的含量为23.6%.     

一步聚合法制备壳核型、可控阶层结构的羰基铁/聚苯乙烯复合微球

采用改进的悬浮聚合法合成了一系列粒径和结构可调的羰基铁粉/聚苯乙烯磁性高分子微球.利用傅立叶变换红外光谱仪、热重分析仪、X射线衍射仪、扫描电镜等分析了微球的结构、化学成分及形貌.结果表明,通过改变苯乙烯单体和聚乙烯醇(PVA)的加入量,可以制备三类不同形貌和结构的复合微球,即多孔复合微球,无孔复合微球和含"带状"突起的...     

特殊形态接枝高分子颗粒的合成

表面接枝高分子微球具有分子结构的可设计性 ,分散稳定性好 ,被用于高效催化剂的载体、药物释放控制和疾病治疗等生物医学领域 ,因而引起了许多高分子材料和生物医学工作者的极大兴趣[1～ 3] .我们用链转移自由基聚合法合成了一端为苯乙烯基封端的聚乙二醇 ( PEG)和聚 ( N -异丙基丙烯酰胺 )等亲水性大分子单体 .在与疏水性单体如苯乙烯等的二元分散共聚反应中 ,利用接枝共聚物在溶液中的自组装 ,制备了粒径分布均一 ,颗粒表面形态光滑 ,同时表面具有功能性高分子链的微球 [4～ 8] .传统的合成高分子微球的研究主要是以苯乙烯或甲基丙烯酸…     

含钆温度敏感高分子核磁共振成像(MRI)造影剂的制备及研究

合成了一种新型可聚合型含钆单体,在温敏单体N-异丙基丙烯酰胺存在下,采用无皂乳液聚合法一步制备了含钆温度敏感的高分子微球.透射电子显微镜测试表明微球呈单分散性;动态光散射测试表明高分子微球的平均水合粒径约260 nm,呈现很窄的粒径分布;当温度从25℃升到45℃时,其粒径减小约60 nm,表明含钆高分子微球具有较好的温度敏感性.体外MRI测试表明,所得高分子微球的体外弛豫率为8.01(mmol/L)-1S-1(3 T),能有效的增强MRI信号,具有优良的MRI造影功能.上述结果表明,所得微球作为一种多功能MRI造影剂,在生物医学领域极具应用前景.     

AMPS/MMA二元共聚微球的超声无皂乳液制备与表征

将超声辐射无皂乳液聚合作用于含有2-丙烯酰胺基-2-甲基丙磺酸（AMPS）和甲基丙烯酸甲酯（MMA）的水溶液中,在不加任何引发剂和乳化剂的条件下合成AMPS/MMA二元共聚高分子微球,考察了超声反应时间对单体转化率的影响,用FTIR、TGA-DSC、TEM和粒度分析仪等技术进行了表征,并初步探讨了聚合反应机理。结果表明,合成得到的高分子微球粒径在0.77μm左右,分散均匀,且具有较好的热稳定性     

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。     

相分离聚合法:(Ⅰ)羧酸型共聚功能微球的合成

Crosslinked functional microspheres with Carboxylic group have been synthesized by the method of Phaseseparated polymerization from monomers of methacrylic acid and other vinyl-type monomers. The effects of reaction condition such as comonomer, crosslinking agent, initiator and polymerization temperature, as well as polymerization time on the morphological structure of microspheres formed have been studied. The functional polymeric microspheres with good spherical form, diameter near 5 micrometers, narrow dispersion in diameter and contained carboxylic group can be synthesized stably.     

Functional fluorescent microspheres

Novel functional microspheres encapsulated with tris(8-hydroxyquinolinolato) aluminum were synthesized by dispersion polymerization. They were characterized by scanning electron microscopy (SEM) and electrical conductance titration. The average diameter and size distributions (SDs) of these microspheres were determined by laser diffraction size analysis. The microspheres show good fluorescence.     

Precipitation polymerization in acetonitrile and 1‐propanol mixture: synthesis of monodisperse poly(styrene‐co‐divinylbenzene) microspheres with clean and smooth surface

Precipitation polymerization of styrene (St)–divinylbenzene (DVB) has been carried out using acetonitrile/1‐propanol mixture as the reaction media and 2,2′‐azobisisobutyronitrile (AIBN) as initiator. Monodisperse micron‐sized poly(St‐co‐DVB) microspheres with clean and smooth surface were synthesized in the absence of any stabilizing agent such as surfactants or steric stabilizers. The effects of various polymerization parameters such as 1‐propanol fraction in the reaction media, initiator and total monomer concentration, DVB content, polymerization time and polymerization temperature on the morphology, particle size and size distribution were investigated. It was found that smoothly shaped stable particles were obtained when less than 70 vol% of 1‐propanol was used in the media. The particle size increased with the AIBN concentration, whereas the change of uniformity was less obvious. Monodisperse microspheres were obtained when the total monomers loading ranged from 0.5 to 3 vol%. The particle diameter ranged from 2.73 to 1.87 µm with an increasing DVB content and the uniformity was enhanced. In addition, the yield of microspheres increased with the increasing total monomer, initiator, and DVB concentration and polymerization time. Copyright © 2010 John Wiley & Sons, Ltd.     

聚二乙烯基苯微球的合成及其表征研究

采用分散聚合方法制备了聚二乙烯基苯微球 ,研究了引发剂、稳定剂、单体 溶剂比例和溶剂种类对微球粒径及其分布的影响 ,在适当的条件下可以得到平均粒径较大、粒径分布较窄的微球 .用红外光谱法研究了聚合物微球内稳定剂、悬挂双键以及对位和间位二乙烯基苯含量随聚合过程的进行发生的变化 .测得的微球TG曲线表明 ,聚合物微球具有良好的热稳定性 .     

带有酰胺侧基的中空手性高分子微球的合成及其分离性能

合成了带有手性基团的多孔高分子微球, 并将其作为高效液相色谱手性固定相用于分离制备盐酸贝那普利的一个重要中间体(R)-α-羟基苯丁酸乙酯.     

Polysaccharides as a source of advanced materials: Cellulose hollow microspheres for drug delivery in cancer therapy

Biocompatible hollow poly(methyl acrylic acid-co-N-isopropylacrylamide-co-ethyleneglycol dimethacrylate)@cellulose succinate (P(MAA-co-NIPAAM-co-EGDMA)@CS) microspheres have been synthesized by employing uniform silica-MPS microspheres as template. Silica spheres were synthesized via Stöber method involving tetraethyl orthosilicate. The surface of resulting silica Stöber microspheres was modified using 3-methacryloxypropyltrimethoxysilane (MPS), a polymerizable silane coupling agent. The above reagent introduces carbon–carbon double bonds on microspheres’ surface. This strategy uses the copolymerization of the following monomers, methacrylic acid (MAA), N-isopropyl acrylamide (NIPAAM) and the ethyleneglycol dimethacrylate (EGDMA), which was used as cross-linker, aiming at fabricating the first shell. Distillation precipitation polymerization method was carried out with 2,2-azobis(2-methylpropionitrile) as initiator in acetonitrile aiming at coating the inorganic microspheres with organic shell of the above-mentioned copolymer. In continuation, cellulose succinate and cellulose powder was absorbed through electrostatic interactions onto microspheres’ surface and the isolated product was cross-linked through esteric bonds formation. The cellulose succinate hollow microspheres were obtained after the silica core removal. The resulting spheres were characterized by Fourier transform infrared spectroscopy and observed by scanning and transmission electron microscopy. Dynamic light scattering was used to study the hydrodynamic diameter of the synthesized microspheres. The anticancer drug daunorubicin was loaded in the spheres, and its release behavior was evaluated at acidic and slightly basic pH conditions, aiming at evaluating its behavior at the healthy and pathogenic tissues.     

微米级单分散共聚物微球的制备

用分散聚合法制备了苯乙烯 甲基丙烯酸甲酯微米级单分散共聚物微球 ,粒径为 5 4 μm .将分散聚合体系与乳液聚合体系进行了比较 ,并对共聚物微球的形貌、粒径分布及共聚情况进行了表征研究 .     

Controllable preparation of magnetic polymer microspheres with different morphologies by miniemulsion polymerization

Magnetic poly(styrene-co-acrylic acid-co-acrylamide) microspheres were prepared by water-in-oil-in-water (W/O/W) miniemulsion polymerization of monomers in the presence of Fe3O4 nanoparticles. The copolymerizable monomers of acrylic acid and acrylamide were used not only to modify the surfaces of the microspheres with functional groups, but also to act as viscosity regulators to control the morphology and size of these microspheres. It was experimentally observed that the surfaces of these microspheres were functionalized with NH2 groups produced by copolymerization, the morphologies (sphere, ringlike, and one-hole) of the microspheres were controlled by the concentration of copolymerizable monomers, and all samples prepared were superparamagnetic. The possible mechanism of formation of these magnetic microspheres is also discussed.