The electroinitiated polymerization of styrene: Part 1

Electrolysis of a solution of styrene and sodium borofluoride in sulpholane gives rise to low molecular weight polystyrene at the anode. The polymerization occurs by a cationic mechanism initiated by electrolytically produced boron trifluoride co-catalysed by either hydrogen fluoride and/or water. Kinetics in a single compartment cell and a divided compartment cell show differences. Acceleration occurs in the anode compartment of the divided cell with current efficiencies higher than those observed in the single cell. This is ascribed to the presence of an electrolytic termination reaction occurring in the single cell.     

The electroinitiated polymerization of styrene: Part 2

Electrolysis of a solution of styrene and sodium borofluoride in dimethyl acetamide gives rise to polystyrene at the cathode. The polymerization occurs by an anionic mechanism initiated by solvated electrons produced during electrolysis. Kinetics in a single compartment cell and a divided compartment cell show differences. Acceleration occurs in the cathode compartment of the divided cell giving rise to high current efficiencies. Evidence is given for the presence of an electrolytic termination reaction occurring in the single cell.     

Cationic Photopolymerization of 1, 2-Epoxy-6-(9-carbazolyl)-4-oxahexane Initiated by Sulfonium Salt and Iron Arene Complex

The photopolymerization of 1,2-epoxy-6-(9-carbazolyl)- 4-oxahexane (ECOH) initiated with dual function sulfonium salt bis [4(diphenylsulfonio)-phenyl] sulfide-bishexafluoroantimonate (Cyracure ^® UVI 6974) and ( η⁵-2,4-cyclopentadien- 1-yl) [(1,2,3,4,5,6-η)-(1-methylethyl)benzene]-iron (+)-hexafluorophosphate (—1) (Irgacure ^® 261) has been studied. Higher rate constant values and degrees of polymerization are established for the ECOH photopolymerization initiated with Cyracure ^® compared with those obtained using Irgacure ^® . The influence of temperature on the rate of ECOH photopolymerization, molecular weight and conversion limit is discussed. The activation energy for the photopolymerization of ECOH with the sulfonium salt has been established.     

用于舰船防污涂料的环氧甲萘醌微胶囊的性能调控

该文以聚丙烯酸酯为囊壁,环氧甲萘醌为囊芯制备了环氧甲萘醌微胶囊,并将其应用于舰船防污涂料中。采用透射电镜(TEM)和纳米粒度仪对微胶囊形貌进行表征。考察了微胶囊核壳质量比对涂料中环氧甲萘醌渗出量及涂料防污效果的影响。结果表明,制备的环氧甲萘醌微胶囊平均粒径约为323.5 nm。环氧甲萘醌微胶囊的核壳质量比为1∶7时,制备的涂膜中环氧甲萘醌的释放速率最平稳,涂层防污效果最好。该类微胶囊的研究,为获得使用寿命长、毒性小、价格低廉的舰船防污涂料提供了新途径和新思路。     

Liquid Phase Oxidation of 1, 4 and 1, 2-Dihydronaphthalene

The two isomeric olefins, 1,2 and 1,4-dihydronaphthalene, were subjected to autoxidation. Although rates as well as product patterns were entirely different for both olefins, it could be shown that an α-peroxy radical is a common intermediate with both substrates. The difference in behaviour is caused by the fact that with the 1,4-isomer chain propagation takes place by hydrogen abstraction, while addition to the reactive double bond occurs with the 1,2-isomer. By cooxidation experiments of the two olefins a high conversion into an epoxide could be obtained, which was shown to be a reaction intermediate in the formation of β-tetralone from the 1,2-isomer. The products obtained on cobalt ion catalyzed oxidation were in agreement with the accepted mechanism for this reaction. The fact that attack by oxygen with both isomers occurs only at the α-position is contrary to what could be expected on the basis of the thermodynamic stability of the products, but is in agreement with the recently proposed principle of least motion. With base catalysis almost exclusively the dehydrogenation product naphthalene was obtained.     

The polymerisation of 2-furyl vinyl ketone

Summary 2-Furyl vinyl ketone was polymerised using anionic, cationic and free-radical initiators. Yields and molecular weights varied with the type of activation. Whereas radical polymerisation gave a product possessing a regular vinylic structure, other kinds of units were detected in the polymers prepared with anionic and cationic catalysts.     

Lichtinduzierte polymerisation, 2. Polymerisation von methylmethacrylat mit 9,9-disubstituierten acridanen

With 9-Benzyl-9-phenylacridane and with 9-Benzyl-10-methyl-9-phenylacridane as representatives of 9,9-disubstituted Acridanes it is shown that these compounds decompose under the influence of light even in the absence of hydrogen-donating agents with formation of free radicals which are able to initiate the polymerization of methylmethacrylate.     

偏三甲苯-甲醇烷基化制均四甲苯催化剂的研究

采用自制催化剂对偏三甲苯-甲醇烷基化制均四甲苯研究,探讨了不同反应工艺条件对催化剂活性的影响研究,得出催化剂的最佳使用工艺条件是反应温度为350℃、反应压力条件为1. 5 MPa、空速条件为0. 5～1. 0 h-1、原料配比为n(甲醇)/n(偏三甲苯)=2;同时考察高温焙烧以及预积碳处理两种改性手段对催化剂性能的影响,实验结果证实上述两种改性手段均能明显提高催化剂的活性。     

1-苄基-4-（4-甲氧基）-苯基-1，2，3-三唑的合成

采用氯苄和叠氮化钠在乙醇中反应制备了苄叠氮,进而与对甲氧基苯乙炔进行1,3-偶极环加成反应合成了未见报道的1-苄基-4-（4-甲氧基）-苯基-1,2,3-三唑,产率达到了48％,产物结构经NMR和MS确认。     

4-羟基-2,2,6,6-四甲基哌啶氮氧自由基的制备

阐述了一种新的氧化方法，即在二价金属盐－过氧化氢（30％）氧化体系中，氧化4－羟基－2，2，6，6－四甲基哌啶醇成4－羟基－2，2，6，6－四甲基哌啶氮氧自由基，在70摄氏度下反应10h，产率95％以上。     

4–氨基–1,2,4–三唑硝酸盐的合成及晶体结构研究

以甲酸和水合肼为原料,经甲酰化、环化、酸化合成了4–氨基–1,2,4–三唑硝酸盐(4–ATN),收率97.2%。采用IR、1H–NMR、质谱、元素分析及四圆单晶衍射仪等手段对目标化合物进行了表征,并进行了热性能分析。结果表明:4–ATN晶体属单斜晶系,存在分子内和分子间氢键。空间群为Cc,晶胞参数:a=0.955 1(4)nm,b=0.524 5(2)nm,c=1.181 0(5)nm;α=90°,β=96.627(6)°,γ=90°;V=0.587 7(4)nm3,Dc=1.663 g/cm3,Z=4,μ=0.151 mm–1,F(000)=304,μ(Mo Kα)=1.109 mm–1,R1=0.034 2,wR2=0.106 1。     

2,2,6,6-四甲基-4-甲氧基哌啶氮氧自由基制备方法的改进

阐述了一种制备 4 -甲氧基 -2 ,2 ,6 ,6 -四甲基哌啶氮氧自由基的改进方法 :以四氢呋喃为溶剂 ,0℃时 ,在N2 的保护下和NaH的存在下 ,2 ,2 ,6 ,6 -四甲基 -4 -羟基哌啶氮氧自由基与MeI在室温反应 5h。分离混合物 ,得到粘稠状红色液体 ,加入正己烷 ,在 -2 0℃条件下储存 ,结晶出针状深红色的晶体。熔点 :4 2～ 4 3℃ ,产率 70 %以上     

Sorption of N2, CH4 and CO2 in Silicalite-1

An isosteric sorption apparatus has been used to obtain data for the sorption of N₂, CH₄ and CO₂ in Silicalite-1 over the temperature range 0–70°C. Isotherms have also been determined in a high pressure sorption balance at equilibrium pressures up to 20 atm. Isosteric heats of sorption have been calculated from these sorption data. Separation factors calculated from Henry's Law constants determined from the initial slopes of the single-component isotherms have been found to be in good agreement with experimental separation factors. The single-component sorption data have been fitted to various isotherm models and the Ideal Adsorbed Solution theory has been used to predict a binary sorption isotherm from the respective single-component data. The predicted isotherm is in good agreement with the corresponding experimental isotherm.     

Mechanism and evaluation in electroinitiated copolymerization coatings of acrylonitrile and acrylic acid

Adherent films of copolymers on different metal surfaces were formed by an electrolytically initiated polymerization of acrylonitrile (AN) and acrylic acid (AA) in 0.05N H₂SO₄ aqueous solution. The electrolysis was carried out under a constant current. Hydrogen overvoltages for five different metals used as the cathode were measured in order to interpret the nature and quality of the coating. Solutions containing varying volume fractions of AN and containing different electrolytes gave rise to coatings of varying film thickness. Based on the analyses of copolymer compositions, it is believed that the polymer was formed at the cathode by a free-radical propagation mechanism. The film hardness and the adhesion between the polymer and the metal surface were measured with an Arco microknife. Furthermore, the scanning electron microscope (SEM) was used to examine the structure of the film surface and cross section. The corrosion rates of the coated and uncoated metals in substitute ocean water were also measured for purposes of evaluation of the coatings.     

Einfluß des stofftransportes bei der polymerisation von äthylen und 1-okten mit Ziegler-Katalysatoren

The polymerization of ethylene and 1-octene with supported Ziegler-catalysts was investigated with regard to the influence of mass transport of monomers on the kinetics, molecular weight and molecular weight distribution. In the case of the polymerization of ethylene, it was found that for certain conditions of reaction the mass transport of ethylene can influence the kinetics of polymerization respectively the catalyst efficiency strongly. The molecular weight and molecular weight distribution of the polyethylene formed are practically not affected by the conversion as well as particle size of catalyst and polymer. The molecular weight distribution however is affected by the concentration of the catalyst. The polymerization process of ethylene in suspension is distinguished by chemical and physical processes. A continuous chain initiation, for example, is based on the continuous reduction of the catalyst particles to small pieces during the course of polymerization. An apparent chain termination respectively catalyst deactivation can occur when catalyst particles are encapsulated within the growing polymer particles. The polymerization of 1 -octene for similar conditions of reaction gave polymers which were solved completely in the system used. The molecular weight distribution of the polymer formed nevertheless was very broad. This indicates that the mass transport of the monomers through the solid phase of polymer cannot be the main reason for the broad molecular weight distribution of the polymers which are produced by heterogeneous Ziegler-catalysts in suspension.     

水杨醛缩3-(5-取代苯基-1,3,4-(噁)二唑-2-亚甲硫基)-5-吡啶-3-基-1,2,4-三唑-4-胺席夫碱的合成及抗菌活性

3-(5-取代苯基-1,3,4-噁二唑-2-亚甲硫基)-5-吡啶-3-基-1,2,4-三唑-4-胺与水杨醛缩合制得相应的席夫碱类化合物,其结构经MS、IR、1HNMR和元素分析确证。用试管稀释试验法研究了目标化合物的体外抑菌活性,结果表明多数化合物在体外表现出较好的抑菌活性。     

Effects of applied potential on electroinitiated copolymerisation of α-methylstyrene and β-bromostyrene

Electroinitiated cationic copolymerisation of α-methylstyrene and β-bromostryene has been studied at various applied potentials. The relationship between copolymerisation potential and resulting copolymer composition was investigated. The advantages of employing constant potential electrolysis over constant current electrolysis are discussed in terms of the reactivity ratios. The reactivity ratios of the monomers are calculated according to the integrated Lewis-Mayo equation.     

Nitriles in heterocyclic synthesis: Synthesis of pyrazolo[1, 5-a] pyrimidine,pyrazolo[1, 5-c][1, 2, 4]triazine and pyrazolo[4, 3-e][1, 2, 4]triazine derivatives

5-Amino-3-phenylpyrazole ( 1 ) reacted with enaminonitriles 2a – c to afford the pyrazolopyrimidines 5a , b and the 5-substituted aminopyrazole 8 . 5a reacted with arenediazonium chlorides and benzaldehyde to give 6 and 7 respectively. Also, o-hydroxyacetophenone afforded the fused pyrazole derivative 9 on treatment with 1 . Enaminonitrile 3 coupled with 11 and arenediazonium chlorides to give 12 and 13 respectively. Cyclization of 13a , b afforded the pyrazolotriazines 15a , b .     

2-溴-3-甲基-1,4-二甲氧基萘的合成

以2-甲基萘醌为原料,经过催化氢化、甲醚化和溴化3步反应,合成了维生素K2的重要中间体2-溴-3-甲基-1,4-二甲氧基萘(1)。以钯碳为催化剂加氢还原,得到了2-甲基-1,4-二羟基萘(3),收率98.8%;3在碱性条件下用硫酸二甲酯进行甲氧基保护,生成2-甲基-1,4-二甲氧基萘(4),收率95.1%;4与溴反应可以得到1,收率90.1%。3步反应总收率由传统方法的48.7%提高到84.6%。