Viscosity of water at 20°C

The viscosity of water in the 19.5–25.5°C temperature range was redetermined by a group of workers at the Norwegian Institute of Technology in 1988, under the stimulus from the IUPAC Subcommittee on Transport Properties headed by Professor J. Kestin. This Note explains an apparent discrepancy, reported in the original work, between the damping-sensitive and the period-sensitive solutions of the working equations employed. The disagreement between the two viscosities reduces to 0.0001 mPa · s, or 0.01 %, when the appropriate corrections to the period are introduced.Paper dedicated to Professor Joseph Kestin.     

Studies of linear polymer dimensions of poly(4-chlorostyrene) in various solvents around the θ temperatures by intrinsic viscosity

Intrinsic viscosities of poly(4-chlorostyrene) solutions in isopropyl-benzene and n-propylbenzene at temperatures above and below the theta (θ) temperatures of these solvents were measured using a capillary viscometer. The viscosity measurements were performed on three poly(4-chlorostyrene) samples having molecular weights (M?;_v) 1.75 × 10⁶, 6.5 × 10⁵ and 2.7 × 10⁵. A smooth and continuous contraction below the θ temperatures was observed for both solvents. The temperature dependence of [/eta] can be represented by a master curve in a plot of α³/eta|/tau|M^1/2 (g^1/2 mol^?1/2) versus |/tau|M^1/2 (g^1/2 mol^?1/2), where α/eta = [/eta(T)]/[/eta(θ)]^1/3 is the expansion factor and /tau = (T - θ)/T is the reduced temperature. A universal plot of reduced viscosity size (α/eta) versus reduced blob parameter (N/N_c) shows the achievement of collapsed state for T<θ. The prediction of thermal blob theory is also verified for T > θ. The temperature dependence of intrinsic viscosity, both below and above the θ temperature, exhibits similar behaviour to the temperature dependence of dipole moments for both of these solvents.     

Physicochemical Characteristics of Brown Rice as Influenced by Gamma Irradiation

Brown rice samples prepared from medium grain (Mars) and long grain (Lemont and Tebonnet) varieties were irradiated at 0, 1.0, 2.0 and 3.0 kGy and analyzed. The amount of solids leached upon cooking increased with increased dose levels indicating the degradation of the rice grain structure. Damaged starch for Mars decreased to the 1.0 kGy level and increased thereafter. Moisture content remained constant between 13% and 14%. Amylose content was not greatly affected by irradiation. Peak viscosity, setback values, final viscosity, viscosity at 50°C, and consistency all decreased with increasing levels of irradiation. As radiation increased, an increase in the yellow color of the rice samples was noted.     

用磺化稠油降低稠油粘度的初步研究

在低温下 (15～ 2 0℃ )用 5 0 %～ 6 0 %的硫酸将辽河稠油磺化 ,得到了一系列磺化稠油 ,在 5 0℃粘度为 115 3mPa·s的辽河稠油中按质量比 2 g/kg加入磺化稠油 ,使 5 0℃粘度降至 786～ 914mPa·s ,降粘率为 19.8%～31.8%。将磺化反应进行优化 ,得到磺化稠油的最好制备条件 :5 5 %硫酸 ,用量为稠油的 1.5 % ,在 15℃反应 2h。得到的磺化稠油在加剂量为 2 g/kg时使稠油 5 0℃粘度下降 30 .8%。稠油降粘率与加剂量的关系曲线很复杂 ,经过一个明显的极大值和一个极小值 ,极大值对应的加剂量为 2 g/kg ,即最佳加剂量。讨论了稠油降粘机理。图 1表 1参 2。     

Shear viscosity of methanol and methanol + water mixtures under pressure

Shear viscosities have been measured for methanol up to 400 MPa at 298, 313, and 323 K and for methanol-water mixtures (a) at 0.1 MPa and 278 K and (b) up to 300 MPa at 298 K. Where a comparison is possible the results are in good agreement with literature data. The data for the mixtures are discussed in terms of hydrogen bonding in methanol and water and by the use of excess viscosities.     

液体的粘度与导热系数间的关系

将流体粘度和导热系数的自由体积模型与平衡性质的统计力学理论相结合,导出用液体蒸发潜热表示的关联液体粘度与导热系数的基本方程。对30种有代表性的物质(354个点)的平均相对关联误差为3.56％。应用蒸发潜热与温度的关系式,进一步得到以温度表示的关联上述两种传递性质的方程,对30种物质的关联误差为3.24％。     

Viscosity and surface tension of p-xylene-ethylacetate liquid mixtures

Experimental density, viscosity and surface tension data are reported for p-xylene-ethylacetate mixtures at 20°. 30° and 40°C. over the entire composition range. The presence of interactions has been studied in the light of excess properties.     

Recent Advances with Glycidylamine Resins

A new procedure for the glycidylation of aromatic amines has been developed recently, which leads to resins of lower viscosity, longer shelf-life and higher purity than methods used previously. Resins made by the new process show considerable processing and applications advantages over those made by earlier methods. The new process has also made accessible high purity glycidyl derivatives of amines which have hitherto proved difficult to glycidylate effectively.     

低矿化度污水对聚合物粘度的影响

污水对聚合物的粘度影响极大,直接关系到注聚合物工程的驱油效果和经济效益。根据现场和室内的试验,提出了污水中的含油、杂质、二价铁和污水处理中使用的絮凝剂(带正电)是影响聚合物粘度的主要因素,并确定了蒙古林注聚合物试验条件下的水质标准。     

The viscosity of aqueous KCl solutions in the temperature range 25–200°C and the pressure range 0.1–30 MPa

In this paper, new precise viscosity data are presented for aqueous solutions of KCl; these data cover the temperature range 25–200°C, the pressure range 0.1–30 MPa, and the concentration range 0–4.6 mol KCl/kg H₂O. An empirical correlation which reproduces the data within the experimental precision of ±0.5% is given. The accuracy of the data is estimated to range from ±0.5 to ±1.5%.