Viscosity and density of isobutane measured in wide ranges of temperature and pressure including the near‐critical region

Accurate ηρpT data for isobutane were measured for nine isotherms between 298.15 and 498.15 K using simultaneously a vibrating‐wire viscometer and a single‐sinker densimeter. The maximum pressure was 93% of the saturated for subcritical isotherms and 30 MPa for supercritical isotherms. The density measurements are generally characterized by an uncertainty of ≤0.1%. Allocation errors for temperature and pressure influence significantly their uncertainty in the near‐critical region. A comparison with the equation of state by Bücker and Wagner shows agreement normally within ±0.1%. The near‐critical isotherm 410.15 K reveals differences to ?3.7% exceeding the uncertainty of 1.9%. The uncertainty in viscosity is ≤0.3%. The comparison with the correlation of Vogel et al. yields deviations exceeding the uncertainty of the correlation (3%). The critical enhancement becomes evident for the near‐critical isotherm amounting to 1.4%. The new data will improve the viscosity surface correlation. © 2015 American Institute of Chemical Engineers AIChE J, 61: 3116–3137, 2015     

RHEOLOGICAL CHARACTERIZATION OF NON-NEWTONIAN FLUIDS WITH A NOVEL VISCOMETER

A hydrostatic head viscometer and its novel viscosity equation were developed to determine flow characteristics of Newtonian and non-Newtonian fluids. The objective of this research is to test capabilities of the hydrostatic head viscometer and its novel non-Newtonian viscosity equation by characterizing rheological behaviors of well-known polyethylene oxide aqueous solutions as non-Newtonian fluids with 60 wt.% sucrose aqueous solution as a reference/calibration fluid. Non-Newtonian characteristics of 0.3–0.7 wt.% polyethylene oxide aqueous solutions were extensively investigated with the hydrostatic head viscometer and its non-Newtonian viscosity equation over a 294–306 K temperature range, a 0.14–40 Reynolds number range, and a 55–784 s^?1 shear rate range at atmospheric pressure. Dynamic viscosity values of 60 wt.% sucrose aqueous solution were determined with the calibrated hydrostatic head viscometer and its Newtonian viscosity equation over a 3–5 Reynolds number range at 299.15 K and atmospheric pressure and compared with the literature dynamic viscosity value.     

正癸烷+正戊醇,+1-己醇,+庚醇二元混合物在293.15到363.15K和大气压力下的密度和粘度（英文）

Densities (ρ) and dynamic viscosities (η) for three binary mixtures of n-decane with 1-pentanol, 1-hexanol and 1-heptanol are presented at temperatures from 293.15 to 363.15 K and atmospheric pressure over the entire composition range. The density and viscosity are measured using a vibrating tube densimeter and a cylindrical Couette type rotating viscometer, respectively. Excess molar volumes (VE), viscosity deviations (Δη) and excess Gibbs energy of activation of viscous flow (ΔG*E) are calculated from the experimental measurements. Intermo-lecular and structural interactions are indicated by the sign and magnitude of these properties. Partial molar vol-umes and infinity dilution molar partial volumes are also calculated for each binary system. These results are correlated using Redlich–Kister type equations.     

RHEOLOGICAL CHARACTERIZATION OF NON-NEWTONIAN FLUIDS WITH A NOVEL VISCOMETER

A hydrostatic head viscometer and its novel viscosity equation were developed to determine flow characteristics of Newtonian and non-Newtonian fluids. The objective of this research is to test capabilities of the hydrostatic head viscometer and its novel non-Newtonian viscosity equation by characterizing rheological behaviors of well-known polyethylene oxide aqueous solutions as non-Newtonian fluids with 60 wt.% sucrose aqueous solution as a reference/calibration fluid. Non-Newtonian characteristics of 0.3-0.7 wt.% polyethylene oxide aqueous solutions were extensively investigated with the hydrostatic head viscometer and its non-Newtonian viscosity equation over a 294-306 K temperature range, a 0.14-40 Reynolds number range, and a 55-784 s^-1 shear rate range at atmospheric pressure. Dynamic viscosity values of 60 wt.% sucrose aqueous solution were determined with the calibrated hydrostatic head viscometer and its Newtonian viscosity equation over a 3-5 Reynolds number range at 299.15 K and atmospheric pressure and compared with the literature dynamic viscosity value.     

3-庚3-庚酮+乙酸乙酯、3-庚酮+乙酸丁酯、3-庚酮+TBP、MIBK+TBP二元体系的过量摩尔体积和黏度

常压下测定了3-庚酮+乙酸乙酯、3-庚酮+乙酸丁酯、3-庚酮+磷酸三丁酯（TBP）、4-甲基-2-戊酮（MIBK）+磷酸三丁酯4个二元体系在293.15～318.15 K下的密度和黏度值,计算了二元体系的过量摩尔体积V^E和过量黏度Δη,并用Redlich-Kister方程对V^E和Δη进行了关联。混合溶剂的黏度数据采用Orrick-Erbar(O-E)基团贡献法进行了关联和预测,增加了O-E方法中的(-O)₃-P=O 基团贡献值。结果表明,O-E方法可根据现有的纯溶剂的黏度数据预测得到混合溶剂的黏度,平均误差小于15%。     

Investigation of the Physical and Tribological Properties of Iso-Oleic Acid

Oleic acid was isomerized into iso-oleic acid using a modified ferrite zeolite catalyst. The isomerization produced a mixture of iso-oleic acid isomers, with a methyl branching at the double bond, whose position has been randomly distributed along the fatty-acid chain. The effect of isomerization on the physical and tribological properties of iso-oleic acid relative to oleic acid was investigated. The neat fatty acids and their blends in polyalphaolefin (PAO-6) and high-oleic sunflower oil (HOSuO) base oils were used in the investigations. Relative to neat oleic acid, neat iso-oleic acid displayed: higher kinematic viscosity but lower viscosity index (VI) and acid number; lower pour point (PP) and cloud point (CP); better oxidation stability; similar four-ball (4-ball) antiwear friction and wear; and similar 4-ball extreme pressure weld point. Blends (0–10%, w/w) of iso-oleic and oleic acid in PAO-6 displayed the following similar trends with increasing concentration: mildly decreasing kinematic viscosity at 40 and 100 °C; increasing VI; lower coefficient of friction; and no change in wear. Blends (0–10%, w/w) of iso-oleic and oleic acid in HOSuO displayed the following similar trends: decreasing oxidation stability with increasing concentration; constant PP and CP with increasing concentration.     

DENSITIES AND DERIVED THERMODYNAMIC PROPERTIES OF THE BINARY SYSTEMS OF BENZENE WITH BUTYL METHACRYLATE, ALLYL METHACRYLATE, METHACRYLIC ACID, AND VINYL ACETATE AT 298.15K

Densities of the binary systems of benzene with butyl methacrylate, allyl methacrylate, methacrylic acid, and vinyl acetate have been measured as a function of the composition, at 298.15 K and atmospheric pressure, using an Anton Paar DMA 5000 oscillating U-tube densimeter. The calculated excess molar volumes were correlated with the Redlich-Kister equation and with a series of Legendre polynomials. The excess molar volumes are positive for the four binaries studied.     

DENSITIES AND DERIVED THERMODYNAMIC PROPERTIES OF THE BINARY SYSTEMS OF BENZENE WITH BUTYL METHACRYLATE,ALLYL METHACRYLATE,METHACRYLIC ACID,AND VINYL ACETATE AT 298.15 K

Densities of the binary systems of benzene with butyl methacrylate, allyl methacrylate, methacrylic acid, and vinyl acetate have been measured as a function of the composition, at 298.15 K and atmospheric pressure, using an Anton Paar DMA 5000 oscillating U-tube densimeter. The calculated excess molar volumes were correlated with the Redlich-Kister equation and with a series of Legendre polynomials. The excess molar volumes are positive for the four binaries studied.     

二甲苯与环丁砜混合液粘度和密度测定及关联

在常压下采用U形振动管密度计测定了对二甲苯与环丁砜的混合液在298 15K～353 15K下的密度,用乌氏粘度计测定了此混合溶液在303 15K～353 10K下的粘度,并由密度数据计算出超额体积VE、由粘度数据计算出了不同温度和组成下的混合粘度的变化,同时对不同温度下的超额体积与组成的关系进行了多元回归,对混合粘度变化随组成的关系按Redlich-Kister方程进行了关联。     

碳酸二甲酯相关二元体系粘度和密度的测定及关联

在常压下采用U形振动管密度计测定了碳酸二甲酯-甲醇的混合液在293．15～323．15K和碳酸二甲酯-氯苯的混和液在293．15～343．15K下的密度;用乌氏粘度计测定了这两个混合溶液在相应温度下的粘度,并由密度数据计算出超额体积V^E、由粘度数据计算出了不同温度和组成下的混合粘度的变化Δη,前者V^E、Δη均为负值。后者V^E为正值,Δη基本聚集在0附近。对不同温度下的超额体积、混合粘度变化与组成的关系按Redlich-Kister方程进行了关联,最大标准偏差小于5％;说明这两体系适合采用此方程回归。     

巴豆酸乙酯与乙醇混合液密度和粘度的测定及关联

主要介绍了3-羟基丁酸乙酯合成过程中的相关物系的物性测定.在常压下采用U形振动管密度计测定了巴豆酸乙酯与乙醇的混合液在293.15～343.15 K下的密度,用乌氏粘度计测定了此混合溶液在293.15～343.15 K下的粘度,并由密度数据计算出超额体积V E、由粘度数据计算出了不同温度和组成下的混合粘度的变化Δη,V E和Δη这些值均为负值.同时对不同温度下的超额体积与组成的关系,粘度变化与组成的关系分别用Redlich-Kister方程进行了关联,最大标准偏差小于5%;说明此方程可适用于回归两相体系中上述的物性数据.     

Thermal conductivity and viscosity of normal C2–C6 aliphatic carboxylic Acids

Equipment for measurements of thermal conductivity and viscosity of liquids in the temperature range 273–350 K and at atmospheric pressure is described. The thermal conductivity and viscosity of acetic, propionic, butyric, valeric and hexanoic acids in the liquid state have been measured. The values obtained are compared with published data and the ratio of thermal conductivity, λ, to viscosity, η, is examined in the form of the dimensionless quantities, Mλ/Rη and cpη/λ (Prandtl number).     

乙酸乙酯-1,2-丙二醇二元系的密度、折射率和黏度

常压下测定了乙酸乙酯和1,2-丙二醇二元系在298.15～323.15 K下的密度、折射率和黏度,建立了混合液密度、黏度随组成和温度变化关系的方程。计算了过量摩尔体积V^E,折射率偏差Δn_D,黏度偏差Δη和过量流动活化自由能ΔG^*E。结果表明,过量摩尔体积低温时在全浓度范围内为负值,但随温度升高,在富酯区变为正值;而折射率偏差高温时在富醇区为微小正值,其他情况都是负值;黏度偏差和过量流动活化自由能显示了相同的变化关系,均为负值,且都随温度降低而偏差增大。     

Film-Forming Properties of Blends of High-Oleic Sunflower Oil with Polyalkyl Glycol

The viscosity, density, and elastohydrodynamic film thicknesses of oil-soluble polyalkyl glycols (PAG), high oleic sunflower oil (HOSuO), and their 50/50 (wt.%) blends were investigated. The viscosity and density of the blends were found to be predictable from the corresponding neat oil properties using simple mixing rules. Pressure–viscosity coefficients (PVC) of HOSuO, the two PAGs, and the two 50?wt% HOSuO/50?wt% PAG blends were calculated from measured film thickness data using the Hamrock-Dowson method and compared to values estimated from literature data. Literature pressure-density and viscosity-temperature data for oils with high-oleic acid group content were analyzed using the Tait and Casalini et al. models. Viscosity versus pressure data obtained from these analyses was used to calculate PVC using the Barus and Bair et al. models. The PVC values calculated from the literature data following this procedure showed reasonable agreement with that from film thickness data from this work.     

Glass formation in the LiF-ZnSO<Subscript>4</Subscript> system

The glass-forming ability is investigated in the LiF-ZnSO₄ binary system. It is found that, upon cooling melts at a rate of 10³ K/s, the glass formation is observed in the concentration range 30–60 mol % ZnSO₄. The characteristic temperatures are determined using differential thermal analysis. The density of glasses is measured by hydrostatic weighing. The experimental results obtained are used to calculate the molar volumes and the thermal stability parameters of lithium-containing fluorosulfate glasses.Original Russian Text Copyright © 2005 by Fizika i Khimiya Stekla, Nepomiluev, Reznitskikh.     

Density and viscosity of the binary polyethylene glycol/CO2 systems

Density of CO₂ saturated solutions of polyethylene glycols (PEGs) of different molecular weight was measured in pressure range from 8.0 MPa up to 47.7 MPa at a temperature of 343 K by a volumetric method. To validate the method density of pure CO₂ was measured at different pressures and a temperature of 293 K. The results were compared to the literature data and the accuracy was better than 2%. The density was between 1.17 g/mL for PEG 1000/CO₂ at 14.5 MPa and 1.78 g/mL for the system PEG 4000/CO₂ at 35 MPa. Further, the data were compared to results, obtained by a gravimetric method using magnetic suspension balance (MSB).Viscosity of CO₂ saturated solutions of polyethylene glycols (PEGs) of different molecular weight at different pressures and at a temperature of 343 K was measured using a high pressure view cell. Also a temperature impact on the viscosity of pure PEGs was observed at ambient pressure. After saturating PEG 1500 with 10 MPa of CO₂ pressure its viscosity decreases from 76.6 mPa s to 2.24 mPa s at 333 K. Further addition of CO₂ and increasing the pressure results in even lower viscosity and the highest viscosity reduction was reached at the highest pressure; at 35 MPa viscosity of the system PEG 1500/CO₂ is only 0.665 mPa s.     

Density, viscosity, and surface tension of water+ethanol mixtures from 293 to 323K

Density, viscosity, and surface tension of liquids are important physicochemical properties which affect mass and heat transfer in solutions. The density, viscosity, and surface tension of binary mixture of water+ethanol at 293, 298, 303, 308, 313, 318, and 323 K are reported and compared with the available literature data. The findings of these comparisons show how the measured data are reproducible from different laboratories. The molar volume of water+ ethanol mixtures are also calculated using measured density values. The Jouyban-Acree model was used for mathematical correlation of the data. The relative deviation (RD) was used as an error criterion and the RD values for correlation of density, viscosity, surface tension and molar volume data at investigated temperatures are 0.1±0.1%, 10.4±9.5%, 4.2±3.6%, and 0.3±0.3%, respectively. The corresponding RDs for the predicted properties after training using the experimental data at 298 K are 0.2±0.2%, 14.1±15.8%, 5.4±4.6% and 0.4±0.3%, respectively, for density, viscosity, surface tension, and molar volume data. This study shows that the Jouyban-Acree model can correlate/predict physicochemical properties of the mixtures of solvents at different temperatures with acceptable error in calculation.     

Hydrostatic extrusion under back pressure of high-density polyethylene

The possibility of hydrostatic extrusion of solid polymer under back pressure has been studied. Operation of equipment is described that permits hydrostatic extrusion under back pressure at elevated temperatures. To understand how the pressure influences hydrostatic extrusion, extrusions of polyethylene under back pressure up to 392 MPa were conducted at temperatures below the melting point of polyethylene at atmospheric pressure (T_m¹). Furthermore, hydrostatic extrusion in the solid phase could be conducted at temperatures beyond T_m¹, since the melting point of polyethylene increased markedly with increasing back pressure.     

纳米二硫化钼对冷冻机油密度和黏度的影响

采用聚乙烯吡咯烷酮（PVP-K30）对纳米二硫化钼（MoS2）进行表面化学修饰,配制了分散稳定性良好的环烷基纳米冷冻机油。利用旋转式黏度计和密度仪对5种配比的纳米冷冻机油（二硫化钼质量分数为0.25%、0.5%、0.75%、1%、1.25%、1.5%）在不同温度（288~333K）下的密度和黏度进行了测试,并对其数据进行了拟合关联。实验结果表明：经PVP修饰的纳米MoS2在低浓度情况下在冷冻机油中分散稳定性能良好,且在质量分数之比为1∶1时达到最佳分散效果;纳米冷冻机油的黏度随MoS2和PVP质量分数的增加而下降,在温度较低时更为明显;纳米冷冻机油的密度测量值和计算值基本吻合,其密度黏度关联式的计算值与90%的实验数据吻合较好。该结果为纳米冷冻机油在传热、流动和摩擦领域的应用提供了重要的基础数据。     

Physical and Chemical Characterizations of Normal and High-Oleic Oils from Nine Commercial Cultivars of Peanut

Density and viscosity data as a function of temperature (5–100 °C) were collected for oils (normal and high-oleic) from nine cultivars of peanut. Density decreased linearly (R ² ≥ 0.99) with increasing temperature for all oils, whereas viscosity (dynamic or kinematic) decreased exponentially with increasing temperature. At any particular temperature, dynamic viscosity increased linearly (R ² ≥ 0.95) with decreasing oil density among the various oils. Slopes of the linear fits (with units of kinematic viscosity) for dynamic viscosity versus density plots decreased in an exponential fashion as the measurement temperature decreased. High-oleic oils had both the lowest densities and highest viscosities, with viscosity differences being most apparent at cooler temperatures. Increasing contents of oleic acid, decreasing contents of linoleic acid, and decreasing contents of palmitic acid were each associated with decreased density and increased viscosity among the oils. Two of the three high-oleic oils had the significantly (p < 0.05) highest content of total tocopherols, while the other high-oleic oil was statistically grouped with the oils having the 2nd highest total tocopherol content. This suggests a link between increased total tocopherols and high-oleic peanut oils; however, no obvious linear correlations were observed in tocopherol content and oil physical properties (density or viscosity). The use of trade names in this publication does not imply endorsement by the United States Department of Agriculture-Agricultural Research Service.