Oxyammonolysis Products of Birch Wood and Its Principal Components

The composition of products from oxidative ammonolysis of the principal components of birch wood by mechanochemical treatment with atmospheric oxygen and ammonium persulfate in aqueous ammonia was studied.     

不锈钢中镍的测定方法——丁二酮肟光度法的改进

针对国标GB 223.25丁二酮肟重量法测定镍含量操作步骤繁琐和国标GB 223.23丁二酮肟分光光度法测定镍量含量范围窄的现状,提出了利用氨水和溴酸钾–溴化钾替代氢氧化钠和过硫酸铵的改进方法。研究了氨水用量、溶液pH值及溴酸钾–溴化钾作氧化剂对测试结果的影响。在1∶1的氨水用量约20 mL及pH≥10.2时,该方法的重复性小于1.16%、再现性小于0.86%,测量结果的相对标准偏差小于1%(n=6)。与国标相比,该方法具有快速、易掌握、测量结果准确等优点。     

Oxidative Ammonolysis of Birch Wood

The functional composition of oxidative ammonolysis products obtained from treatment of birch wood with ammoniacal ammonium persulfate using a mechanochemical method was studied.     

Preparation of polyaniline‐sulfate salt ­by emulsion and aqueous ­polymerization pathway without using ­protonic acid

Aniline was polymerized directly into polyaniline‐sulfate salt without using protonic acid in this work. Polyaniline‐sulfate salt was prepared by emulsion and aqueous polymerization pathways. The dopant i.e. sulfate ion in polyaniline‐sulfate salt was generated from ammonium persulfate which was used for oxidizing aniline. Ammonium persulfate acts both as oxidizing agent as well as protonating agent in the polymerization process of aniline to polyaniline salt. The efficiency of oxidizing and protonating power of ammonium persulfate is increased by the use of surfactant. The activity of ammonium persulfate is further increased by the use of sulfuric acid as protonic acid. It may be necessary to consider the effect of sulfate ion which is generated during the oxidation process of aniline in the chemical polymerization of aniline to polyaniline salt by ammonium persulfate either aqueous or emulsion polymerization pathway in the presence of protonic acid/functionalized protonic acid. Copyright © 2001 John Wiley & Sons, Ltd.     

Emulsion Polymerization Pathway for Preparation of Polyaniline‐Sulfate Salt,using Non Ionic Surfactant

In this work, aniline was polymerized directly to the polyaniline‐sulfate salt without using a protonic acid. The polyaniline‐sulfate salt was prepared by emulsion polymerization, using a non ionic surfactant such as poly(ethylene glycol)–block poly(propylene glycol)‐block poly(ethylene glycol). In the aniline oxidation process, to give the polyaniline salt by ammonium persulfate, the sulfate ion is generated from ammonium persulfate and doped on to the polyaniline. Ammonium persulfate acts both as an oxidizing agent, as well as the protonating agent in the aniline polymerization process, to give the polyaniline salt. This result indicates that the effect of sulfate ion, generated by ammonium persulfate during oxidation of aniline to the polyaniline salt, may be taken into consideration in the polymerization process of aniline.     

Concentration and temperature controlled oxidation and cutting of single-walled carbon nanotubes by ammonium persulfate

Science China Chemistry - SWNTs were oxidized by a simple wet chemical method involving treatment in aqueous ammonium persulfate (APS) solution at a certain temperature. Fourier transform infrared...     

利用离子膜电解法改进过硫酸铵生产研究

国内工厂生产过硫酸铵大多采用工艺简单且产品纯度高的电解法,但是电解法在生产过程中存在能耗过高的问题。这一问题限制了过硫酸铵在许多领域的进一步发展。针对这一现象,对硫酸铵电解生成过硫酸铵的设备及工艺进行设计和研究,以期达到降低能耗的目的。实验基于零极距和离子交换膜电解槽的设计,研究了加酸量、抑制剂用量、出入口温度和电解液浓度等因素对电解效率的影响。结果表明,在电解液中加酸并且在阳极液中添加抑制剂对提高电流效率和降低槽电压具有很大的影响,在最优条件下电流效率可达到98%,生产过程能耗显著降低。另外,电解槽还具有连续性生产、占地面积小的优势,进一步解决了厂家所面临的生产成本过高的问题。     

Oxidative Ammonolysis of Vegetable Raw Materials

The influence of the composition of lignocarbohydrate vegetable raw materials, process duration (15-120 min), amount of hydrogen peroxide (0.1-0.9 g per gram of raw materials), and amount of ammonia (0.25-1.5 g per gram of raw materials) on the yield of the target product and on the nitrogen content and the content of functional groups in it in mechanochemical treatment of vegetable wastes with hydrogen peroxide in aqueous ammonia (oxidative ammonolysis) was studied. Sorption and agrochemical testing of the resulting samples as nitrogen-containing ion exchangers and fertilizers was performed.     

The course of emulsion polymerization of vinyl acetate using redox systems of different oxidizing agents

The emulsion polymerization of vinyl acetate (VAc) was carried out by using redox initiation systems of different persulfate cations such as potassium persulfate (PPS), sodium persulfate (SPS), and ammonium persulfate (APS); each of them was coupled with developed acetone sodium bisulfite adduct (AcSBS) as a reducing agent. The rate of polymerization was found to be dependent on the initiator concentration to the powers 1.04, 1.02, and 0.34, respectively. The effect of the different cations of the oxidizing agents upon the stability of the prepared emulsion lattices was studied by using the sedimentation method. The effect of the different cations on the morphological characteristics of some of the produced lattices was also studied. Finally, the activation energies of these reactions for potassium, sodium, and ammonium persulfate were found to be 0.84 × 10⁴, 1.92 × 10⁴, and 6.68 × 10⁴ J/mol, respectively. © 1997 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 35: 3141–3149, 1997     

Kinetic features of ammonium persulfate decomposition in aqueous medium

Russian Chemical Bulletin - Decomposition of ammonium persulfate in an aqueous medium (353–368 K) is limited by decomposition of persulfate ions with a rate constant logk 2 =...     

Preparation of MMA－BA－DMAEMA Nanosized Latex

The terpolymer latex of methyl methacrylate (MMA)/butyl acrylate (BA)/ dimethyl aminoethyl methacrylate (DMAEMA) with diameter of less than 100 nm was prepared by seeding semi-continuous emulsion copolymerization using APS (ammonium pcrsulfate) / TMEDA (N,N,N,N-tetramethylethylenediamine) as the redox initiators and SDS (sodium dodecylsulfate) and OP (P-octylpolyethylene glycol phenylether) as co-emulsifiers. The factors that influenced the process stability of the copolymerization and the particle size of the latex were investigated. The addition of aqueous ammonia as coagulation inhibitor provided better process stability of the copoly- merization. The addition of acetic acid as the acidification agent caused a remarkable reduction of the latex particle size.     

Doping of processable conducting poly(m‐aminophenol) with silver nanoparticles

Processable poly(m‐aminophenol) (PmAP) was synthesized using ammonium persulfate (APS) oxidant in 0.6 M sodium hydroxide solution at room temperature. Soluble silver hydroxide ammonium complex was formed by dissolving silver nitrate in excess liquor ammonia and the thermal decomposition of this complex easily produced silver nanoparticle. Then, in situ silver nanoparticle‐doped PmAP film was obtained by casting PmAP film from dimethyl sulfoxide (DMSO) with silver hydroxide ammonia complex mixture at 140°C. The nanocomposite was characterized by ultraviolet‐visible spectroscopy, Fourier transformed spectroscopy, transmission electron microscopy (TEM), scanning electron microscopy, electron dispersion spectroscopy, thermogravimetric analysis, and X‐ray diffraction analysis. The average size of the nanoparticle was around 130–140 nm as confirmed by the TEM analysis. Synthesized PmAP silver nanocomposite showed the highest DC‐conductivity of 1.03 × 10^?6 S/cm. From the above characterizations, it can be said that silver nanoparticle shows some doping effect on the conductivity of PmAP. The doping level of the silver nanoparticle inside the polymer was optimized in terms of DC‐conductivity of the silver nanoparticle‐doped PmAP film. Copyright © 2009 John Wiley & Sons, Ltd.     

Novel Method of Synthesis of Quaternary Ammonium Tribromides and Investigation of Catalytic Role of Benzyltrimethylammonium Tribromide in Oxidation of Alcohols to Carbonyl Compounds

Stable crystalline organic quaternary ammonium tribromides (QATBs) have been easily synthesized by the oxidation of the corresponding organic ammonium bromides (QABs) with ammonium persulfate. The reactions have been performed under solvent-free conditions in the presence of sulfuric acid and silica as supporting agent. Two equivalents of potassium bromide have been used as the source of additional bromides for quantitative conversion of QABs to QATBs. Ammonium persulfate, a cheap and readily available oxidant, carries out the bromide oxidation to tribromide very effectively under solvent-free conditions. The synthesized QATBs have been shown to catalyze the oxidation of alcohols to carbonyl compounds with hydrogen peroxide as oxidant in good yields under mild reaction conditions.     

Chiral nematic phase formation by aqueous suspensions of cellulose nanocrystals prepared by oxidation with ammonium persulfate

There is continuing interest in the growing family of nanocellulosic materials prepared from plant cell wall material. While most of the research on cellulose nanocrystals has focused on the product of sulfuric acid hydrolysis stabilized by surface sulfate half-esters, cellulose nanocrystals with surface carboxyl groups have also been prepared by oxidation of lignocellulosic materials with ammonium persulfate. The major difference is that the persulfate oxidation leads to nanocrystals stabilized by surface carboxyl groups. Some properties of cellulose nanocrystals from cotton and wood, prepared by persulfate oxidation, are compared with those observed for nanocrystals prepared by sulfuric acid hydrolysis. Evidence from polarized light microscopy showed that the nanocrystal suspensions prepared by persulfate oxidation also form chiral nematic ordered phases in water.     

Oxidative and photooxidative degradation of poly(acrylic acid)

The oxidative degradation of poly(acrylic acid) (PAA), a water soluble polymer, was studied at various temperatures with different concentrations of persulfates, potassium persulfate (KPS), ammonium persulfate (APS) and sodium persulfate (SPS). The photodegradation of PAA was also examined with APS as oxidizer. The degraded samples were analyzed for the time evolution of molecular weight distribution by gel permeation chromatography. A theoretical model based on the continuous distribution kinetics was developed that accounted for the polymer degradation and the dissociation of persulfate. The rate coefficients for the oxidative and photooxidative degradation of PAA were determined from the parametric fit of the model with experimental data. The rate of degradation increased with increasing amount of persulfate in both oxidative and photooxidative degradation. The rate of degradation also increased with increasing temperature in the case of oxidative degradation.     

分光光度法快速测定钢铁中的锰、磷、硅

用硝酸、过硫酸铵溶解试样,在较高温度下,分别用过硫酸铵光度法测定钢铁中的锰含量,铋磷钼蓝光度法测定磷含量,抗坏血酸硅钼蓝光度法测定硅含量。方法简便、快速、灵敏、准确并已应用于锰、磷、硅自动分析仪。     

Facile synthesis of poly(hydroxyethyl acrylate) by frontal free‐radical polymerization

We report the first synthesis of poly(hydroxyethyl acrylate) (PHEA) without solvent by free‐radical frontal polymerization (FP) at ambient pressure. In a typical run, the appropriate amounts of reactant (hydroxyethyl acrylate) and initiator (1,1‐di(tert‐butylperoxy)‐3,3,5‐trimethylcyclohexane) (Luperox 231) were mixed together at ambient pressure. FP was initiated by heating the wall of the tube with a soldering iron, and the resultant hot fronts were allowed to self‐propagate throughout the reaction vessel. Once initiated, no further energy was required for polymerization to occur. To study the macrokinetics, we also produced PHEA frontally with ammonium persulfate as initiator and dimethyl sulfoxide as the solvent. The dependences of the front velocity and front temperature on the initiator concentration and reactant dilution were investigated. The front temperatures were between 124 and 157 °C, depending on the ammonium persulfate concentration. Thermogravimetric analysis indicates that PHEA prepared by FP with ammonium persulfate as initiator had higher thermal stability than solvent‐free frontally prepared PHEA with Luperox 231 as initiator. © 2007 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 45: 873–881, 2007     

Cyclopolymerization of diallylamine derivatives in dimethyl sulfoxide

Diallyl quaternary ammonium chlorides, bromides and N-alkyldiallylamine hydrochlorides were polymerized with ammonium persulfate (APS) in dimethyl sulfoxide (DMSO). The dependences of yield and molecular weight of polymers on polymerization conditions were examined and quaternary ammonium chlorides were found to have better polymerizability than bromides. The poly(diallyl quaternary ammonium chlorides) obtained with APS—DMSO system are expected to have quite high molecular weights, as determined from the measurement of limiting viscosity numbers of the polymers in NaCl aqueous solution.     

Solid State Oxidation of Thiols to Disulfides Using Ammonium Persulfate

A solid state method for the oxidation of thiols is described that uses benign oxidant, ammonium persulfate.     

纤维素与己内酰胺的接枝共聚反应

以过硫酸铵和过硫酸钾为引发剂,在碱性环境下进行纤维素与己内酰胺的接枝共聚反应.采用红外光谱仪(FT-IR)、扫描电子显微镜(SEM)及X射线衍射仪(XRD)对接枝共聚物的分子结构、表观形貌和结晶性进行了表征.通过单因素实验重点考察了单体用量、引发剂浓度、反应温度和反应时间等对接枝共聚物接枝率的影响.结果表明:以3 g纤...