微米级单分散聚苯乙烯微球的制备

以苯乙烯(St)为单体、偶氮二异丁腈(AIBN)为引发剂、聚乙烯吡咯烷酮(PVP)为分散稳定剂,在乙醇-水反应介质中,采用分散聚合法制备了微米级单分散聚苯乙烯(PS)微球。分别用电镜扫描和激光粒度仪表征了PS微球表面形貌、粒径及粒度分布,探讨了影响PS微球粒径及粒度分布的诸多因素。结果表明,AIBN用量(以单体质量计,下同)大于5.0%或PVP用量(以单体质量计,下同)小于2%时,PS粒子间有聚并现象;当St浓度为10%、AIBN用量为2.5%、PVP用量为5.5%、醇水质量比为90∶10、聚合温度为70℃时,制备的PS微球粒径为1.612μm、粒度分散系数为0.357,微球单分散性及球形度最佳。     

单分散氢氧化钙/聚苯乙烯微球的制备与表征

以葡萄糖水溶液为反应介质,在氧化钙消化成氢氧化钙的过程中,加入苯乙烯单体和引发剂,采用原位悬浮聚合法成功制备了聚苯乙烯(PS)包覆氢氧化钙[Ca(OH)2]形成Ca(OH)2/PS微球.考察了葡萄糖水溶液、苯乙烯、稳定剂聚乙烯醇以及反应温度对单分散Ca(OH)2/PS微球的粒径及粒子分散系数的影响,得出较佳合成条件.在较佳条件下制备的Ca(OH)2/PS微球平均粒径为30～40 μm,粒子分散系数为0.08～0.10.扫描电镜照片表明,Ca(OH)2/PS具有良好的球形度,表面光滑、无破损.红外光谱表征显示,产物为Ca(OH)2/PS微球.     

Preparation of polystyrene/poly(methyl methacrylate) core‐shell composite particles by suspension‐emulsion combined polymerization

Suspension‐emulsion combined polymerization process, in which methyl methacrylate (MMA) emulsion polymerization constituents (EPC) were drop wise added to styrene (St) suspension polymerization system, was applied to prepare polystyrene/poly(methyl methacrylate) (PS/PMMA) composite particles. The influences of the feeding condition and the composition of EPC on the particle feature of the resulting composite polymer particles were investigated. It was found that PS/PMMA core‐shell composite particles with a narrow particle size distribution and a great size would be formed when the EPC was added at the viscous energy dominated particle formation stage of St suspension polymerization with a suitable feeding rate, whereas St‐MMA copolymer particles or PS/PMMA composite particles with imperfect core‐shell structure would be formed when the EPC was added at the earlier or later stage of St suspension polymerization, respectively. It was also showed that the EPC composition affected the composite particles formation process. The individual latex particles would exist in the final product when the concentrations of MMA monomer, sodium dodecyl sulfate emulsifier, and potassium persulfate initiator were great in the EPC. Considering the feature of St suspension polymerization and the morphology of PS/PMMA composite particles, the formation mechanism of PS/PMMA particles with core‐shell structure was proposed. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2009     

Preparation and characterization of monodisperse magnetic poly(styrene butyl acrylate methacrylic acid) microspheres in the presence of a polar solvent

Magnetic poly(styrene butyl acrylate methacrylic acid) [P(St–BA–MAA)] microspheres were prepared by emulsifier‐free emulsion polymerization in the presence of a polar solvent and a ferrofluid prepared by a coprecipitation method. The effects of some polymerization parameters, such as the medium polarity, reaction temperature, initiator content, and surfactant content in the ferrofluid, on the particle diameter and particle size distribution of magnetic P(St–BA–MAA) microspheres were examined in detail. The results showed that the electrostatic repulsion in the polymerization system significantly affected the monodispersity of the resulting magnetic polymer microspheres. The proper electrostatic repulsion, achieved through changes in the medium polarity and amount of surfactant in the polymerization system, improved the monodispersity, but a higher or lower repulsion led to a decrease in the monodispersity. Although the existence of surfactant and magnetite particles reduced the monodispersity more or less, the polymerization behavior of an emulsifier‐free emulsion polymerization in the presence of the ferrofluid was analogous to that of a conventional emulsifier‐free emulsion polymerization. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 87: 1733–1738, 2003     

Synthesis of monodisperse crosslinked poly(styrene‐co‐divinylbenzene) microspheres by precipitation polymerization in acetic acid

Poly(styrene‐co‐divinylbenzene) microspheres with size ranging from 1.6 to 1.8 μm were prepared in acetic acid by precipitation polymerization. The particle size and particle size distribution were determined by laser diffraction particle size analyzer, and the morphology of the particles was observed with scanning electron microscope. Besides, effects of various polymerization parameters such as initiator and total monomer concentration, divinylbenzene (DVB) content, polymerization time and polymerization temperature on the morphology and particle size were investigated in this article. In addition, the yield of microspheres increased with the increasing total monomer concentration, initiator loading, DVB concentration and polymerization time. In addition, the optimum polymerization conditions for synthesis of monodisperse crosslinked poly(styrene‐co‐divinylbenzene) microspheres by precipitation polymerization in acetic acid were obtained. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012     

The effects of acrylate monomers and polystyrene addition on the morphology of DOP‐plasticized styrene–acrylate polymer particles prepared by SPG emulsification and suspension polymerization

Fairly uniform copolymer particles of methyl acrylate (MA), butyl acrylate (BA), or butyl methacrylate (BMA) were synthesized via Shirasu porous glass (SPG) membrane and followed by suspension polymerization. After a single‐step SPG emulsification, the emulsion composed mainly of the monomers. Hydrophobic additives of dioctyl phthalate (DOP), polystyrene molecules, and an oil‐soluble initiator, suspended in an aqueous phase containing poly(vinyl alcohol) (PVA) stabilizer and sodium nitrite inhibitor (NaNO₂), were subsequently subjected to suspension polymerization. Two‐phase copolymers with a soft phase and a hard phase were obtained. The composite particles of poly(St‐co‐MA)/PSt were prepared by varying the St/PSt ratios or the DOP amount. The addition of PSt induced a high viscosity at the dispersion phase. The molecular weight slightly increased with increasing St/PSt concentration. The multiple‐phase separation of the St‐rich phase and PMA domains, observed by transmission electron microscopy, was caused by composition drift because the MA reactivity ratio is greater than that of St. The addition of DOP revealed the greater compatibility between the hard‐St and soft‐MA moieties than that without DOP. The phase morphologies of poly(St‐co‐MA), poly(St‐co‐BMA), and their composites with PSt were revealed under the influence of DOP. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 99: 1195–1206, 2006     

聚苯乙烯-聚甲基丙烯酸甲酯核-壳粒子的制备

由种子乳液聚合法制备了聚苯乙烯-聚甲基丙烯酸甲酯核-壳粒子。以过硫酸钾(KPS)为引发剂,辛基酚聚氧乙烯醚(OP-10)为乳化剂,合成了聚苯乙烯(PS)种子核;连续滴加甲基丙烯酸甲酯(MMA),在核表面富集MMA,制备了粒径范围在0.16~0.67μm的核-壳粒子;当单体苯乙烯与甲基丙烯酸甲酯(St/MMA)的比为30∶70(质量比)时,所得粒径在0.18μm,粒径分布为0.012。差示扫描量热(DSC)研究显示,复合粒子的玻璃化转变温度(Tg)为97.2℃,峰形单一,表现出良好的热性能。     

Uniform Polystyrene Particles by Dispersion Polymerization in Different Dispersion Medium

Using PVP K-30 as steric stabilizer and AIBN as initiator, uniform polystyrene (PS) particles were prepared by dispersion polymerization of styrene in ethanol/water and isopropanol/ water media. The effects of initiator and stabilizer concentration, alcohol/water volume ratio on the average sizes and size range of PS particles were investigated. Unifrom PS particles in the size range of 0.7-1.7 μm were obtained. The results showed that higher stabilizer concentration led to PS particles with smaller average sizes, and higher initiator concentration caused greater average particle sizes. It was also found that the average sizes reduced and size ranges became narrow as the polarity (solubility parameter) of dispersion medium employed was increased.     

Polymer–metal composite particles: Metal particles on poly(St‐co‐MAA) microspheres

Poly(styrene‐co‐methacrylic acid) P(St‐co‐MAA) microspheres with a monodisperse size distribution were prepared by emulsifier‐free emulsion copolymerization of St and MAA. The effects of MAA content on the polymerization rate and the content of MAA in the copolymer were investigated by gravimetrical and IR methods, respectively. The results of XPS measurement indicated the presence of a carboxyl functional group. By chemical metal deposition, nickel or palladium particles were formed and deposited on the surface of P(St‐co‐MAA) microspheres to form P(St‐co‐MAA)Ni or P(St‐co‐MAA)Pd composite particles. XRD measurement and TEM observation confirmed that nickel and palladium metal particles in a small size (20–40 nm) were distributed on surface of the copolymer microspheres. © 2000 John Wiley & Sons, Inc. J Appl Polym Sci 75: 1693–1698, 2000     

反应体系组成对纳米SiO_2/PS复合粒子粒径及分布的影响

研究了在纳米SiO2粒子表面的苯乙烯原位聚合反应中,反应体系的组成(单体、引发剂、稳定剂及纳米SiO2粒子用量)对纳米SiO2/PS复合粒子的形态、粒径大小及分布的影响。结果表明,当纳米SiO2粒子与单体质量比为5%,苯乙烯质量分数为25%,引发剂及稳定剂用量分别为单体用量(质量比)的0.15%和1.5%时,制备出的纳米SiO2/PS复合粒子呈球形,表面光滑无明显缺陷,颗粒之间分散性很好,粒径为0.923μm,分散系数为0.108。     

乳液聚合法制备PSA纳米微球与PS纳米微球的性能测定

以苯乙烯(St)和甲基丙烯酸(MAA)为原料,采用乳液聚合法共聚制备羧基化聚苯乙烯(PSA)纳米微球。通过改变乳化剂(SDS)的用量、St/MAA的质量配比控制微球性质和大小。利用透射电镜(TEM)、扫描电镜(SEM)、傅里叶红外光谱(FTIR)、差示扫描量热仪(DSC)、热重分析仪(TGA)和Zeta电位仪对PSA纳米微球进行表征。FTIR结果证实MAA成功引入到微球中,TEM和SEM表明当乳化剂用量为单体总质量的10%时,得到大小均匀,直径为45 nm的PSA微球。PSA的玻璃化转变温度和热分解温度随MAA的含量增加而提高。纯PS表面带负电荷,Zeta电位为-17 mV。共聚后的PSA纳米颗粒,其St与MAA物质的量比为10/1. 0,10/1. 5和10/2. 5时,Zeta电位分别为-31. 9、-39. 6和-44 mV。上述结果表明,采用共聚是调节PS微球热性质及表面性质的有效途径。     

Monosize polystyrene latices carrying functional groups on their surfaces

In this study, monosized polystyrene (PS) latices were prepared by dispersion polymerization of styrene in isopropanol-water media using poly(acrylic acid) (PAA) as a steric stabilizer and 2,2′-azobisizobutyronitrile (AIBN) as an initiator. The effects of initiator and stabilizer concentrations, alcohol/water and monomer/dispersion medium ratio on the polymerization kinetics, and the size and monodispersity of PS latices were experimented with in a stirred reactor system. Monosize PS beads in the size range of 1.0–3.0 μm were obtained. The PS latex obtained in the first step having a diameter of 2.3 μm were used as the seed latex, and styrene/acrylate monomers, acrylic acid (AA), 2-hydroxyethyl methacrylate (HEMA), and dimethylaminoethyl methacrylate (DMAEMA) were copolymerized onto the PS latex particles. The incorporation of functional groups to the surface and bulk structure of PS was confirmed by IR, FTIR, XPS, and zeta potential measurements. © 1994 John Wiley & Sons, Inc.     

St-BA-BVP无皂共聚物阳离子乳胶粒大小及形态研究

合成阳离子共单体 1-丁基 ,4 -乙烯吡啶溴化铵 ( BVP) ,并以偶氮二异丁基咪盐酸 ( A IBA)作引发剂 ,制备苯乙烯 /丙烯酸丁酯 ( St/ BA )共聚物乳液 ,通过 TEM研究改变 BVP的浓度、St/ BA主单体的配比及单体加料方式对 P( St/ BA / BV P)乳胶粒大小形态的影响 ,结果表明批量法和单体全滴加法制备的乳胶粒形状规则、分布均匀、半连续法制备的乳胶粒子呈多分散分布 ,粒径相差很大 ,且 P( St) / P( BA)得到的乳胶粒呈明显的核壳结构。     

Environmentally benign precipitation copolymerization of methacrylate ester and styrene to make polymeric microspheres in supercritical carbon dioxide

The polymeric microspheres were synthesized by the precipitation copolymerization of glycidyl methacrylate (GMA) with methacrylic acid(MAA) or 2‐hydoxyethyl methacrylate (2‐HEMA) containing styrene (ST) in SC‐CO₂. Scanning electron microscopy (SEM) showed that the products were spherical microparticles, with the addition of MAA and/or 2‐HEMA as the monomer, with diameter of 0.2–2 μm. The effects of copolymerization pressure, temperature, and ratios of GMA/MAA, ST, and/or GMA/2‐HEMA, on the particle size and morphology were investigated in detail. A new experiment setup is proposed for the large amount of production, based on the rule of lower monomer concentration, more stable system, and better use of the present polymerization apparatus. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 103: 2425–2431, 2007     

分散聚合法制备亚微米级单分散聚苯乙烯微球

以醇和水的混合液为分散介质,聚乙烯基吡咯烷酮（PVP）为分散剂、偶氮二异丁腈（AIBN）为引发剂,利用分散聚合法制备亚微米级的单分散聚苯乙烯（PS）微球。分别讨论分散剂的用量以及分散介质的溶解度参数对PS微球粒径的影响。结果表明,当分散介质溶解度参数和单体苯乙烯的溶解度参数越接近时,所制得的PS微球粒径越大,反之越小;随着分散剂PVP量的增加,微球的粒径减小,粒径分布变窄;所制得的聚苯乙烯微球表面光滑,呈均匀的球形。     

The synthesis and characterization of lanthanide-encoded poly(styrene-co-methacrylic acid) microspheres

Lanthanide-encoded polystyrene microspheres with methacrylic acid (MAA) as a co-monomer and with diameters on the order of 2 μm and a very narrow size distribution were synthesized by two-stage dispersion polymerization (2-DisP). These microspheres were designed as a platform for mass cytometry-based bioassays. Different lanthanides (Ln) were loaded into these microspheres during the synthesis, through the addition of LnCl₃ salts and excess MAA to the reaction after about 10% conversion of styrene, i.e., well after the microsphere nucleation stage was complete. Different levels of MAA were employed to investigate the relationship between the number of carboxyl group on the particle surface and the amount of MAA used. The reaction remained well controlled with both 2 and 4 wt % MAA. As monitored by inductively coupled plasma (ICP) mass spectrometry, we found high incorporation efficiency (>95%) of Ln ions into the particles when the total amount of LnCl₃ salts in the reaction mixture was sufficiently small. The Ln incorporation efficiency decreased with the increasing amount of LnCl₃ salts. Mass cytometry analysis shows that individual microspheres contain ca. 10⁵-10⁸ chelated lanthanide ions, either a single element or a mixture of elements. This method of incorporating lanthanide into P(S-MAA) particles through the second stage of two-stage dispersion polymerization yields microspheres suitable for the highly multiplexed detection of biomolecules.     

Synthesis of monodisperse crosslinked polystyrene microspheres via dispersion copolymerization with the crosslinker‐postaddition method

Monodisperse crosslinked polystyrene microspheres were prepared by the dispersion copolymerization of styrene and divinylbenzene in a mixed solvent of ethanol and H₂O. 2,2′‐Azobisisobutyronitrile and poly(N‐vinyl pyrrolidone) were used as the initiator and steric stabilizer, respectively. The crosslinker‐postaddition method was adopted through a slow addition of a crosslinking agent into the dispersion system at a certain time after the beginning of the polymerization. The effects of the postaddition recipe, postaddition beginning time, postaddition velocity, and agitation rate on the particle size, size distribution, and morphology were discussed. The resulting polymer microspheres were characterized with scanning electron microscopy and laser particle analysis. Crosslinked polystyrene microspheres with a narrow size distribution and a 12.0% crosslinker level were obtained with a size of 1.0 μm through the crosslinker‐postaddition method. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 2008     

超声波引发苯乙烯分散聚合反应制备SiO2/PS复合粒子

在系统研究超声波场下辅助引发苯乙烯(St)分散聚合反应规律的基础上,利用超声波的分散、粉碎、活化、引发等多重作用,在实现纳米SiO2粒子于反应介质中均匀分散的同时,引发St单体在纳米SiO2粒子表面进行分散聚合反应,制备出二氧化硅/聚苯乙烯(SiO2/PS)复合粒子,并运用扫描电子显微镜(SEM)、透射电子显微镜(TEM)、红外光谱(FTIR)、热重分析(TGA)、X射线衍射谱(XRD)及X射线光电子能谱(XPS)等多种测试手段对SiO2/PS复合粒子的形貌、粒径及分布、表面特性、化学组成及结构等进行了表征。     

Interfacial‐initiated seeded emulsion polymerization: preparation of polystyrene/poly(methacrylic acid) core/shell particles in the absence of surfactant

Composite polymer particles with hydrophobic polystyrene (PSt) as the core and hydrophilic poly(methacrylic acid) (PMAA) as the shell were prepared through two‐stage emulsion polymerization without any surfactant. In the first step, narrowly distributed PSt seed particles were prepared by surfactant‐free emulsion polymerization with 2,2′‐azobis(2‐methylpropionamide) dihydrochloride (AMPA) as the initiator. In the second step, hydrophilic PMAA shells were fabricated onto PSt seed particles through redox interfacial‐initiated seeded emulsion polymerization with cumyl hydroperoxide (CHPO)/ferrous sulfate/ethylenediaminetetraacetic acid (EDTA)/sodium formaldehydesulfoxylate (SFS), where the initiation took place mainly at the interface between PSt seed particles and the aqueous medium. The composite particles were characterized with transmission electron microscopy, fourier transform infrared spectroscopy and dynamic light scattering, and the results show that a core/shell structure was successfully built. Hydrodynamic radius (R_h) of the composite particles increased with the amount of polymerized monomers in the seeded emulsion polymerization. Copyright © 2006 Society of Chemical Industry     

Dependence of morphological changes of polymer particles on hydrophobic/hydrophilic additives

Fairly uniform microspheres of poly(styrene‐co‐methyl methacrylate) were prepared by employing a microporous glass membrane [Shirasu porous glass (SPG)]. The single‐step SPG emulsification, the emulsion composed mainly of monomers, hydrophobic additives, and an oil‐soluble initiator, suspended in the aqueous phase containing a stabilizer and inhibitor, was then transferred to a reactor, and subsequent suspension polymerization followed. The droplets obtained were polymerized at 75°C under a nitrogen atmosphere for 24 h. The uniform poly(styrene‐co‐methyl methacrylate) microspheres with diameters ranging from 7 to 14 μm and a narrow particle‐size distribution with a coefficient of variation close to 10% were prepared by using SPG membrane with a pore size of 1.42 μm. The effects of the crosslinking agent and hydrophobic additives on the particle size, particle‐size distribution, and morphologies were investigated. It was found that the particle size decreased with a narrower size distribution when the additives were changed from long‐chain alkanes to long‐chain alcohols and long‐chain esters, respectively. Various microspheres with different morphologies were obtained, depending on the composition of the oil phase. The spherical poly(styrene‐co‐methyl methacrylate) particles without phase separation were obtained when using an adequate amount of the crosslinking agent and methyl palmitate as an additive. © 2000 John Wiley & Sons, Inc. J Appl Polym Sci 77: 1013–1028, 2000