Physical Properties of Petroleum Waxes. I. Effect of Oil Content

The effect of oil content on the physical properties of five microcrystalline waxes having widely different oil content have been investigated. It has been observed that the physical properties are affected to a great extent by the variation in oil content. Oil content has a profound effect on viscosity, hardness, and crystallinity of waxes. The effect is not so profound in the case of melting point.     

Estimation of the equation of state exchange energy and entropy parameters of a polymer-solvent pair by intrinsic viscosity measurements

The intrinsic viscosity data of linear poly(4-chlorostyrene) in n-propylbenzene and isopropylbenzene were used to estimate the equation of state exchange energy (X₁₂) and entropy (Q₁₂) parameters. The quantities estimated for X₁₂ were 6.7 and 8.1 J cm^?3 and those of Q₁₂ were ?0.069 and ?0.063 J cm^?3 deg^?1 in n-propylbenzene and isopropylbenzene, respectively. The average values of the chain unperturbed dimension constant (K_o) and the characteristic ratio (C_x) were found to be 0.55 × 10^?3 dl mol^1/2g^?3/2 and 10.54, respectively, from the intrinsic viscosities measured at the corresponding θ-temperatures.     

An alternative method for evaluation of intrinsic viscosity

An alternative method for determination of intrinsic viscosities is described which evolves from the application of l'Hǒpital's rule to the expression defining the intrinsic viscosity. The method yields independent evaluations of the intrinsic viscosity and does not involve extrapolation beyond the range of experimental data or rely on a theoretical expression associated with such extrapolations. The application of the method is illustrated and comparisons are included with the results obtained by traditional approaches.     

用改进的Eyring方程推算无限稀释扩散系数

在Ｅｙｒｉｎｇ绝对速率理论的基础上，提出一个关联扩散自由体积的关系式，从而得到改进的扩散系数计算方程，可从纯物质粘度推算无限稀释扩散系数，方程不含任何待定参数．对８２个各类体系共３３２点扩散系数数据，计算平均相对偏差为１２．１％，而Ｗｉｌｋｅ－Ｃｈａｎｇ方程对同样体系的计算偏差为１４．８％，Ｓｉｄｄｉｑｉ－Ｌｕｃａｓ方程的偏差为１２．３％．     

SBS浓溶液流动行为与粘度模型的研究

研究了诸因素对丁二烯－苯乙烯嵌段共聚物（SBS1401）的环已烷浓溶液和甲苯浓溶液粘度的影响，上述溶液的质量百分数范围为2％－25％，温度范围为25℃-50℃。结果表明，溶液的粘度随浓度的增大而增加，随剪切力和剪切速率的增大而减上；溶液的流动曲线符合幂律定律，并根据所测定的数据，利用回归方法对实验数据进行了处理，获得了在一定温度下，描述本体系溶液粘度特性的两变量的半经验关联式。     

20W／40铁路内燃机车多级四代油的研制

中国石化石油化工科学研究院、铁道科学研究院、大连石化公司和兰州炼化总厂研制的２０Ｗ／４０铁路内燃机车四代油，经理化性质分析及１Ｇ２和ＣＲＣＬ－３８台架评定符合ＣＤ级柴油机油指标，行车试验结果表明，油品粘度、碱值、摩擦副磨损值与参比油相当，在固定式铁路内燃机车发动机台架评定表明节能效果大于１％。     

低渗透油田粘度效应的实验研究

通过不同粘度流体的岩心流动模拟实验，揭示粘度变化对流体渗流及开发效果的影响。研究结果表明：渗透率一定时，原油的粘度越低，渗流越接近线性达西流。低渗透油田热洗井作业时，高温虽可解除部分蜡质、沥青质等的沉积，但又造成近井带原油脱气，流动阻力增加，影响油田开发速度和效果。     

用羧甲基化法改善沙蒿胶水溶性的研究

为提高沙蒿胶的水溶性而使其应用得以拓宽，采用向其大分子链引入羧甲基基团，制备羧甲基沙蒿胶的方法。考察了影响降低沙蒿胶水不溶物含量的因素，实验结果表明，氢氧化钠用量为0．8％～1．6％、水乙醇体积比(1．5～2．5)：20、氯乙酸用量0．6％～0．8％、反应温度50～65℃及反应时间为3-4h时，可使改性羧甲基沙蒿胶的水不溶物含量由55％降至4％，并使其表观粘度显提高。     

Viscosimetric Study of Multicomponent Liquid Mixtures Containing Oxygenated Compounds

Viscosities for the ternary mixtures, 1,4-dioxane + 1-butanol + cyclohexane and 1,4-dioxane + 2-butanol + cyclohexane, were determined at temperatures of 298.15 and 313.15 K. From these data the viscosity deviations were calculated and they are negative over the whole composition range. The results have been compared to predictions by the group contribution method proposed by Wu.