抗菌型淀粉接枝苯丙乳液的合成与性能

通过选取植物源天然抗菌剂甘草、茶多酚、肉豆蔻、肉桂油等制备一系列抗菌型淀粉接枝苯丙乳液。通过傅里叶变换红外光谱(FT-IR)对抗菌型淀粉接枝苯丙乳液的结构进行表征,利用激光粒度分析仪对乳液的粒径分布进行分析,通过热重分析对乳液的热稳定性进行表征,研究系列抗菌型淀粉接枝苯丙乳液对大肠杆菌、金黄色葡萄球菌的抗菌性能。结果表明,天然抗菌剂的用量对乳液的稳定性和单体转化率影响较小,乳液的热稳定性较好,乳液粒径(70~95)nm;乳液粒径为纳米尺寸且粒度分布较窄时,乳液性能优良。当天然抗菌剂在乳液中浓度为5%时,乳液抗菌性能较好,节约成本。对不同种类抗菌剂的乳液横向比较表明,天然抗菌剂茶多酚制备的乳液对大肠杆菌的抑菌作用最强,天然抗菌剂肉桂油制备的乳液对金黄色葡萄球菌的抑菌作用最强。     

不同乳液及填料对水性阻尼隔声材料性能影响研究

选择了醋酸乙烯酯乳液、丙烯酸酯乳液和苯乙烯-丙烯酸酯乳液共3种不同类型的乳液及各种无机填料,制备得到不同的水性涂料,对水性涂料的复合损耗因子及隔声量等性能进行了测试,考察了乳液类型、乳液含量、乳液共混、填料种类及含量等对阻尼性能及隔声性能的影响.实验结果表明单一乳液阻尼温域较窄,乳液共混可以拓宽有效阻尼温域;通过加入云...     

固体石蜡/丙烯酸改性乳液相行为的研究

初步研究固体石蜡及固体石蜡丙烯酸改性乳液的相行为,讨论固体石蜡乳液及改性乳液的温度对折射率的影响、乳化剂用量对乳液粘度的影响、温度对乳液粘度的影响及乳化时间对乳液粘度的影响。结果表明,两种乳液的折射率随温度变化不大,粘度随着乳化剂用量的增大而增大,且随着乳化时间的增加而逐渐增大。     

有机硅乳液的研究及进展

聚合物乳液及技术已成为高分子材料科学和工程的重要领域,在国民经济中发挥着巨大的作用。本文介绍了五种类型的有机硅乳液:聚硅氧烷乳液、硅微乳、聚硅氧烷/丙烯酸酯共混乳液、共聚乳液及复合乳液。阐述了各种乳液的制备方法,对各种乳液的性能及应用进行了综合评价,提出了有机硅乳液的发展前景。     

聚丙烯酸酯改性聚氨酯复合乳液研究进展

总结了聚丙烯酸酯改性聚氨酯(PUA)复合乳液(包括PUA共混乳液、PUA共聚乳液、PUA核壳结构乳液、PUA互穿网络乳液)的制备方法和性能特点,详细介绍了近年来PUA复合乳液的新进展,并对PUA复合乳液的发展作了一些展望。     

羟基硅油乳液的研究与应用

介绍了羟基硅油乳液的常规乳液、微乳液和细乳液的制备方法,并对其应用进行了系统综述.     

马来酸酐接枝聚丙烯(MAH-g-PP)乳液成膜条件研究

测定MAH-g-PP(马来酸酐接枝聚丙烯)乳液在N2氛下的的热重曲线,确定乳液成膜温度的大致范围。研究了乳液固含量,成膜温度和时间对乳液膜性能的影响。并用PU(聚氨酯)乳液来改善MAH-g-PP乳液的成膜性,研究了共混乳液中PU乳液与MAH-g-PP乳液质量比对乳液膜性能的影响。结果表明:MAH-g-PP乳液在固含量为10%、成膜温度为185℃、成膜时间为40 min时乳液膜的综合性能较好。在共混乳液中,当MAH-g-PP乳液与PU乳液的质量比为9∶1时,乳液的成膜性得到提高,且乳液膜的性能较好。     

丙烯酸酯共混乳液的粒径和流变性能研究

将纯丙乳液和苯丙乳液通过乳液共混制备出丙烯酸酯共混乳液,探讨了共混比例、共混温度、共混pH值和共混工艺对丙烯酸酯共混乳液的粒径及其分布的影响,并进一步研究了共混乳液粒径大小及分布对其流变性能的影响。结果表明:共混乳液为假塑性流体;随着共混比例和共混温度的升高,共混乳液粒径减小,黏度增大;随着共混pH值的升高,乳液粒径先增大后减小,黏度总体上呈增大趋势;半连续工艺制备的共混乳液粒径分布最窄、黏度最大,连续工艺制备的共混乳液粒径分布最宽、黏度最小,间歇工艺制备的共混乳液粒径分布和黏度居中。     

乳液的发展及蜡乳液的应用

蜡乳液作为特种蜡的一个重要类别,由于其特殊的性质发展潜力巨大.从乳液发展、乳液分类、乳液稳定性等几方面进行了考察,阐述了蜡乳液的应用前景,对蜡乳液的研发工作提出了指导和建议.     

国内苯丙乳液改性的研究进展情况

介绍了有机硅改性苯丙乳液和环氧改性苯丙乳液以及聚氨酯改性苯丙乳液、纳米SiO2改性苯丙乳液等的发展情况,并简要地对苯丙乳液改性的未来方向作了展望。     

Refractory compounds of basic composition for the monolithin lining of steel-teeming ladles

Conclusions Questions of the method of production of basic ramming compounds at Panteleimonovka Refractory Plant and their use in the monolithic lining of the walls of 160-ton steel-teeming ladles of the No. 2 Converter Shop of Kirvoi Rog Steel Combine are considered.An analysis of the wear of the lining during service showed that it occurs as the result of spalling of the sintered zone and salamandering of the lining. The use of a movable thermally insulated lid made it possible to hold the temperature of the ladle lining within limits of 730–1120°C between heats and to obtain a basic rammed lining life of 21–39 heats as opposed to an average life for the shop of 14.8 heats.A reserve for increasing the ladle basic lining life is optimization of the thermal conditions of its service, including high-temperature heating of the lining before pouring of the metal, the use of thermally insulated lids with the minimum consumption of time for placing of them, an increase in the life of the well refractory to the life of the walls and bottom, and elimination of cooling of the lining between heats.A Discussion: Problems of the Production and Use of Refractories for the Lining of Steel-Teeming Ladles. [For the start of the discussion see No. 8 (1988) and for the continuation Nos. 9–12 (1988) and Nos. 1–3, 5, and 7 (1989).]Deceased.I. I. Glaka, N. F. Drobot, N. V. Kurmaz, B. P. Zinchenko, S. A. Poznyak, I. M. Ryaboshapkin, V. V. Slushko, A. A. Chulkov, Yu. Bormatov, S. I. Vanchyuk, V. I. Dobrovol'skii, B. G. Zhuravel', N. I. Kiyan, L. I. Nekrasov, N. M. Sokolov, P. V. Khomenko, G. A. Nikitenko, S. Dorgobuzov, P. I. Valiev, N. N. Gorbatko, V. I. Kovalenko, and M. I. Lyakhov of Krivoi Rog Steel participated in the preparation and tests of the basic monolithic linings.Translated from Ogneupory, No. 8, pp. 1–4, August, 1989.     

Gel permeation chromatography measurements on PVC resins and plasticisers

The value of gel permeation chromatography (g.p.c.) measurements of PVC resins is discussed in relation to quality control of commercial suspension types. Some examples of simple solvent fractionation and precipitation with methanol are given. In addition, chromatograms of selected plasticisers are shown for analytical identification together with an indication of an approximate determination of the mol. wt. of plasticisers ranging from 400–10,000. Finally a short discussion of the influence of the parameters of operation, i.e. flow rate, volume of injection and concentration of the solution in tetrahydrofuran, is given. It is concluded that g.p.c. determinations of weight-average mol. wt. are in fair agreement with light-scattering measurements.     

Effect of the density of the electronic states at the valence orbital of the bridge redox molecule on the dependence of the tunnel current on the overvoltage in the case of fully adiabatic electron transition

Effect of the density of the electronic states at the valence orbital of the bridge redox molecule on the dependence of the tunnel current on the overvoltage and on the width at half maximum of the current-overvoltage curve is studied. A number of the approximate expressions for the density of states, the tunnel current and the width are obtained in the fully adiabatic limit for different particular cases. It is shown that at small values of the coupling of the electronic levels of the electrodes with the valence orbital of the redox molecule and the small values of the bias voltage two regions of the reorganization Gibbs energy exist with different dependence of the width on the reorganization Gibbs energy. The results of calculations of the density of states, the tunnel current and the width are presented and used for the interpretation of the experimental data [N.G. Tao, Phys. Rev. Lett. 76 (1996) 4066, I. Visoly-Fisher, K. Daie, Y. Terazono, C. Herrero, F. Fungo, L. Otero, E. Durantini, J.J. Silber, L. Sereno, D. Gust, T.A. Moore, A.L. Moore, S.M. Lindsay, PNAS 103 (2006) 8686].     

The compositions of some unhydrolyzed naturally occurring waxes,calculated using functional group analysis and fractionation by molecular distillation,with a note on the saponification of carnauba wax and the composition of the resulting fractions

Summary Methods for the determination of acid, ester, hydroxyl, and ketone (or aldehyde) groups and of mean molecular weights of small samples of natural waxes are reported. Complete analyses can be made on 0.5 g. of sample. A simplified procedure for quantitative separation of acid and unsaponifiable fractions of a wax is also reported. Molecular distillations of beeswax, caranda wax, crude and refined candelilla wax, and ouricury wax, have fractionated these complex mixtures into simpler ones. Hydrocarbons and free unsubstituted alcohols and acids, if present, distil readily at 150°C. A pot still suitable for convenient molecular distillation of up to 100-g. charges of waxes or other high melting materials is described. A method for the calculation of composition of unhydrolyzed waxes based upon function group analysis of molecular distillation fractions is described. Results of application of this method to the waxes distilled are reported and show the ubiquitousness of hydroxy acids. All of the above waxes and carnauba wax contain major proportions of esters of the hydroxy acids, and none contains as much as one-half simple esters of unsubstituted acids and alcohols. A portion of a dissertation submitted by Thomas Wagner Findley to the Graduate School of the Ohio State University in partial fulfilment of the requirements for the Ph.D. degree. S. C. Johnson and Son Inc. Fellow in Physiological Chemistry, 1946-50.     

Reflection of a shock wave from a rigid wall in a mixture of a liquid metal and solid particles

The problem of reflection of shock waves and expansion waves from a rigid wall in a mixture of liquid iron and small molybdenum crystals is considered. The study is performed within the framework of equilibrium and nonequilibrium approximations of mechanics of heterogeneous media with different pressures of the components. The mathematical model is verified by fitting the dependence of the equilibrium-frozen velocity of sound on the initial pressure in the mixture with available experimental data. In the equilibrium approach, the dependence of the type of the reflected wave on the type of the incident wave is determined. Direct numerical calculations within the framework of the nonequilibrium model of mechanics of heterogeneous media confirmed the validity of the reflection chart obtained. The possibility of significant compacting of molybdenum particles in reflected waves is revealed. Translated fromFizika Goreniya i Vzryva, Vol. 36, No. 4, pp. 97–107, July–August, 2000. This work was performed within the framework of the Integration Project No. 97-24 of the Siberian Division of the Russian Academy of Sciences.     

Chemical nature of pre-asphaltenes from flash pyrolysis tars and supercritical gas extracts

Pre-asphaltenes from flash pyrolysis tars of three Australian coals and a supercritical gas extract of one of these coals were studied by ¹³C and ¹H n.m.r. of the silylated pre-asphaltenes. Further information was obtained by hydrogenolysis of one of the pre-asphaltenes followed by g.c. analysis. ¹³C n.m.r. studies of the silylated derivatives and g.c. analysis of the hydrogenated pre-asphaltene showed the presence of long alkyl chains. The aromaticity of the pre-asphaltenes from the flash pyrolysis tars increased as the rank of the coal increased. The pre-asphaltene from the supercritical gas extract was less aromatic than that from the flash pyrolysis tar of the same coal. Average structural data for each of the pre-asphaltenes are reported.     

恒pH滴定法测定二苯胺中苯胺的含量

在质量浓度为95％的乙醇溶液中。以适当浓度的HCI溶液为滴定剂,分别对系列苯胺标准溶液滴定至选定的pH值,绘制HCI溶液消耗体积与苯胺含量的标准曲线,由该曲线求出未知样中苯胺的含量。结果表明,该方法测量的准确性高,相对误差≤1．2％,相对平均偏差为0.2％,二苯胺的存在对苯胺的测定不产生影响。与现用方法相比,该法不需要进行苯胺与二苯胺的分离,也无需对滴定剂进行标定;该法可用于工业上二苯胺中苯胺含量的测定。     

在Mo-Bi-Ce/SiO_2催化剂上丁烯-2氧化脱氢的内扩散影响

用玻璃流动外循环无梯度反应器研究了Mo—Bi—Ce/SiO_2催化剂上丁烯-2氧化脱氢的内扩散影响.确定了催化剂的有效因子,多孔催化剂的有效因子随反应温度的升高而减小.在内扩散区域的反应活化能为丁烯-2扩散活化能、动力学区域反应活化能的算术平均值.在内扩散区域的丁烯氧化脱氢生成丁二烯的选择性用经验式描述.     

Fractal structure and features of energy-release (combustion) processes in heterogeneous condensed systems

In this work, the theory of fractals has been used to describe the structure of heterogeneous condensed systems (HCS). Features of energy-release processes with variation of the initial structure parameters have been investigated. The microstructure of HCS and the dynamics of its change have been studied as functions of the proportion and properties of their components. It is shown that particles of the components form fractal structures, which are characterized by fractional dimensions. The obtained images of the microstructure reflect the presence of the geometric phase transition “fractal cluster-percolation cluster.” Regularities of reaction-front propagation are determined. It is found that the concentration limits of energy release and combustion are associated with the evolution of fractal structures and the formation (disruption) of a continuous reaction surface. The electrical conductivity of the starting compositions is measured as an indicator of the formation of fractal structures of one or another configuration. Electrical and thermal-physics properties of the samples and energy-release (combustion) parameters are analyzed. The systems exhibit similar behavior in different processes. Near the critical point, the dependence of the parameters studied on concentration has an exponential character. The exponent is close to that determined in percolation theory. A computational algorithm for the contact surface of the components is developed and implemented. The computation results allow one to distinguish the “base block” that influences the combustion rate and to determine the critical concentrations of the components. The study of HCS in the context of the new direction in the geometry of disordered systems—the theory of fractals—is promising for generalization of available experimental data and for predicting the parameters of energy release in HCS with variation in the structural parameters. Institute of Chemical Physics, Russian Academy of Sciences, Moscow 117977. Translated from Fizika Goreniya i Vzryva, Vol. 33, No. 5, pp. 3–19, September–October, 1997.     

13C n.m.r. study of the structure of poly(aspartic acid)

From hydrolysis of the product of thermal polycondensation of aspartic acid, poly(succinimide), under various conditions, a series of samples of thermal poly(aspartic acid) was obtained. These polymers differed by molecular mass and, from n.m.r. spectral evidence, by the contents of α and β peptide bonds, depending mostly on the pH of hydrolsysis. The contents of α and β bonds found were further confirmed by analysis of the n.m.r. spectra of the complex of poly(aspartic acid) with Co(II). Also, spectra of poly(aspartic acid) obtained by debenzylation of poly(β-benzyl-l-aspartate) described in our previous work were analyzed in greater detail. A comparison of racemic and optically pure polymers has shown that the n.m.r. spectra are only slightly affected by stereoregularity, and that stereoregularity is not the cause of the splitting of the various carbon bonds. Analysis of the complicated structure of the spectra, mainly of the carbonyl group, leads us to the conclusion that the distribution of the α and β bonds is random in all the polymers studied.