Synthesis of Monodisperse Polystyrene Particles in the Presence of Sodium Dodecyl Sulfate and Carboxyl-containing Initiator

Emulsion polymerization of styrene in the presence of an anionic surfactant, sodium dodecyl sulfate, in a concentration close to the critical micellization concentration, was studied, as influenced by the pH of the initial reaction mixture and the content of the carboxyl-containing azoinitiator.__________Translated from Zhurnal Prikladnoi Khimii, Vol. 78, No. 6, 2005, pp. 1029–1033.Original Russian Text Copyright © 2005 by Men’shikova, Evseeva, Shabsel’s, Balanina, Sirotkin, Ivanchev.     

苯乙烯和甲基丙烯酸环氧丙酯共聚物单分散粒子的合成

分散聚合;苯乙烯和甲基丙烯酸环氧丙酯共聚物单分散粒子的合成     

Synthesis of Polymethyl Methacrylate Microspheres in the Presence of Dextran and Its Derivatives

Emulsion polymerization of methyl methacrylate initiated by a carboxyl-containing azo initiator in the presence of a polymeric stabilizer (dextran or its functionalized derivatives) was studied with the aim to prepare monodisperse microspheres of polymethyl methacrylate with surface carboxy, amido, and aldehyde groups. The optimal conditions for formation of monodisperse microspheres were found, allowing control of their diameter in the submicrometer range and of the nature and content of surface functional groups.     

Synthesis of Polymethyl Methacrylate in the Presence of 1,3-Diphenyl-1-hydroxytriazene and Nitrobenzene

Radical polymerization of methyl methacrylate in the presence of 1,3-diphenyl-1-hydroxytriazene and nitrosobenzene as sources of stable nitroxyl radicals was studied.     

Solubility of Polymethyl Methacrylate in Organic Solvents

Solubility of polymethyl methacrylate in 12 organic solvents at 30–70°C was studied.     

Monodisperse Crosslinked Microsphere Polymer Particles by Dispersion Copolymerization of Glycidyl Methacrylate and Divinylbenzene

Monodisperse polyglycidyl methacrylate (PGMA) microsphere particles crosslinked with divinylbenzene crosslinker were prepared by single-stage dispersion copolymerization in ethanol medium. 1 wt% of DVB was successfully incorporated due to the costabilizing effect of GMA as a surface-active monomer. This behavior may indicate that the fast formation of stable primary particle leads to monodispersity. The average particle sizes and the particle size distributions increased with the DVB crosslinker concentration. The effects of two different variables (initiator concentration, crosslinker concentration) on the rate of dispersion copolymerization have been investigated. With the initiator concentration, the polymerization procedure mainly depended on the dual natures of general dispersion polymerization, in the crosslinked state. Up to 1 wt% DVB, the particle growth was controlled by the monomer diffusion from the continuous phase into the particle phase.     

混合配体席夫碱稀土茂配合物催化合成聚甲基丙烯酸甲酯

The synthesis of high molecular mass (Mr＞5×105) polymers with a narrow molecular mass distribution (Mr,max/Mr,min＜1.05) is a challenging theme in modem polymer chemistry.     

Synthesis and Characterization of Monodisperse Spherical Zirconia Particles

Monodisperse zirconia spherical particles are prepared by hydrolysis of zirconium propoxide in 2-methoxyethanol in presence of decanoic acid as a shape stabilizer. The powder is analyzed by computer image analysis on TEM micrographs, TG-DSC, FTIR, X-ray diffraction and nitrogen adsorption isotherms. A competition phenomenon between aggregation and individual growth of the particles during precipitation is deduced from the observations.     

单分散TiO2亚微米球的制备与表征

采用乙腈与乙醇混合溶剂体系制备出了单分散的亚微米级TiO2球形胶体颗粒, 并对乙腈相对含量以及实验温度等参数的影响进行了研究. 结果表明5 ℃下乙腈相对含量为70%时可制得高质量的单分散胶体颗粒. 通过TEM、SEM、粒度分析等表征手段, 表明所得胶体颗粒平均直径约为540 nm, 标准偏差在5%以内, 颗粒的多分布系数为0.013, TG-DSC分析表明胶体颗粒为含水量很少的水合TiO2; XRD分析表明单分散TiO2胶体颗粒在600 ℃高温烧结由无定型转变为锐钛矿型, 在900 ℃高温烧结则开始出现金红石型.     

活性聚甲基丙烯酸甲酯和溴甲基化聚苯乙烯偶合反应制备接枝共聚物

采用基团转移聚合、阴离子聚合以及高分子偶合反应的方法,合成了一种结构明确、链长均匀和分子量可控的聚苯乙烯接枝聚甲基丙烯酸甲酯。主链聚苯乙烯由阴离子聚合得到,并进行溴甲基化。支链活性聚甲基丙烯酸甲酯由基团转移聚合制备。经偶合反应后得到分子量为3×10⁴～7×10⁴、多分散性指数D为1.2～1.4的接枝共聚物。溴甲基化聚苯乙烯和活性聚甲基丙烯酸甲酯的偶合反应活性随分子量的增大而降低,理想的反应温度为-20℃。用¹HNMR、GPC和DSC表征接枝产物。和均聚物相比,共聚物的玻璃化温度较低。     

活性聚甲基丙烯酸甲酯活性链和溴甲基化聚苯乙烯偶合反应制备接枝共聚物

采用基团转移聚合、阴离子聚合以及高分子偶合反应的方法，合成了一种结构明确、链长均匀、分子量可控的聚苯乙烯接枝聚甲基丙烯酸甲酯。主链聚苯乙烯由阴离子聚合得到，并进行溴甲基化。支链活性聚甲基丙烯酸甲酯由基团转移聚合制备。经偶合反应后得到分子量为３×１０４～７×１０４、多分散性指数Ｄ为１．２～１．４的接枝共聚物。用１ＨＮＭＲ，ＧＰＣ和ＤＳＣ表征接枝产物。和均聚物相比，共聚物的玻璃化温度较低。     

Synthesis of Monodisperse α-Fe2O3 Particles in Short Periods

Asanimportantmaterialusedformagnetic,pigment,catalysis,gas-sensitiveandmedicalimagingapplications,monodispersehematite(a-Fe2O3)particleshaveattractedmoreattentionsinrecentyears1,2.Althoughvariousmorphologica-Fe2O3particleshavebeensynthesizedbyforcedhydrolysisprocess3,4,inwhichthepropertiesofa-Fe2O3particlesvaryconsiderablywithalargenumberofsynthesisparameterssuchaspH,theconcentrationofreactants,thecoexistentanionsetc.,thereisalackofmethodforpreparingmonodispersea-Fe2O3particlesinshortperiod…     

Effect of Metal Complex Binding on the Properties of Polymethyl Methacrylate

Coordination binding of polymethyl methacrylate with copper(II) ions was studied by IR spectroscopy and viscometry.     

掺C60有机玻璃的吸收光谱研究

研究了Ｃ６０分别在有机玻璃（ＰＭＭＡ）和正己烷中的吸收光谱，发现Ｃ６０在有机玻璃中的吸收峰同在正己烷中相互对应，同时前者的吸收峰相对于后者峰宽变大，峰位产生红移，分析了产生这种现象的原因。     

Synthesis of Monodisperse Al-Substituted Hematite Particles from Highly Condensed Metal Hydroxide Gels

Monodispersed aluminum-substituted hematite particles were synthesized from concentrated mixed solutions of FeCl(3) and AlCl(3) using the gel/sol process. With increasing aluminum content (Al/(Fe+Al)) in the starting solutions, hematite particles became more and more elongated. The product particles exhibited ellipsoidal, rod- and peanut-like shapes, depending on Al concentration. Higher Al content (>20 mol%) in the system greatly suppressed the formation of hematite. Atomic emission spectrometry analysis and lattice parameter measurement confirmed the substitution of Al in hematite particles. Copyright 2000 Academic Press.     

Synthesis of Starch-Grafted Polymethyl Methacrylate via Free Radical Polymerization Reaction and Its Application for the Uptake of Methylene Blue

In this research, a new biodegradable and eco-friendly adsorbent, starch-grafted polymethyl methacrylate (St-g-PMMA) was synthesized. The St-g-PMMA was synthesized by a free radical polymerization reaction in which methyl methacrylate (MMA) was grafted onto a starch polymer chain. The reaction was performed in water in the presence of a potassium persulfate (KPS) initiator. The structure and different properties of the St-g-PMMA was explored by FT-IR, 1H NMR, TGA, SEM and XRD. After characterization, the St-g-PMMA was used for the removal of MB dye. Different adsorption parameters, such as effect of adsorbent dose, effect of pH, effect of initial concentration of dye solution, effect of contact time and comparative adsorption study were investigated. The St-g-PMMA showed a maximum removal percentage (R%) of 97% towards MB. The other parameters, such as the isothermal and kinetic models, were fitted to the experimental data. The results showed that the Langmuir adsorption and pseudo second order kinetic models were best fitted to experimental data with a regression coefficient of R² = 0.93 and 0.99, respectively.     

Synthesis of Highly Charged, Monodisperse Polystyrene Colloidal Particles for the Fabrication of Photonic Crystals

We have developed a series of emulsion polymerization recipes for the synthesis of highly charged, monodisperse polystyrene colloids of diameters between 100-400 nm. These spherical colloidal particles were crosslinked with divinyl benzene and functionalized with 1-allyloxy-2-hydroxypropane sulfonate. These highly charged, monodisperse colloidal particles readily self-assemble into robust three-dimensionally ordered crystalline colloidal arrays (CCAs). These CCAs operate as photonic crystals that Bragg diffract light in the ultraviolet, visible, and infrared regions of the spectrum. Copyright 2000 Academic Press.     

Spherical Polarization Body: Synthesis of Monodisperse Micron‐Sized Polyaniline Composite Particles

A new method to synthesize uniform polyaniline‐coated composite microparticles was contrived considering the surface reactivity and porous structure of substrate polymer particles. It was found that the pore diameter together with the epoxy functional group plays a crucial role in controlling the structure of polyaniline shell. The polyaniline composite particles produced in this study are believed to find great applicability in piezoelectronics and as electro‐rheological fluids.     

Arduino实时在线监测系统在聚甲基丙烯酸甲酯本体聚合过程中的应用

利用自主研发的实时在线监测系统，对不同聚合温度条件下，聚甲基丙烯酸甲酯（PMMA）的本体聚合过程进行实时在线监测，建立"虚拟信号值-反应时间"实时在线监测曲线.通过曲线的变化，可以清晰观察到PMMA本体聚合过程的4个阶段，即诱导期、初期、中期和后期.根据本体聚合"转化率-反应时间"S型曲线的特点，构建"虚拟信号值-反应时间-转化率"关系曲线和聚合物转化率计算公式，并提出PMMA预聚体的预测和实时在线监测方法.方法具有操作简单、实时性强、外界因素影响小和性能稳定等优点，是一种新型的实时在线分析方法.