3. LIQUID LUBRICANTS These can be defined as the lubricants that exist in the liquid state and are more frequently used for the purpose of lubrication. Generally, lubricants do tend to contain 90% base oils and approximately less than 10% of the additives. Usually vegetable or synthetic oils like hydrogenated polyolefins, esters, silicones, fluorocarbons etc. are used as base oils. PROPERTIES OF LIQUID LUBRICANTS The liquid lubricants possess the following general properties: i. Viscosity and viscosity index Viscosity is the resistance to flow of one layer of the liquid over the other. It is the measure of the thickness of a liquid. Viscosity index is the scale which measures the rate of change in viscosity with temperature. Depending upon …show more content…
This property is used to analyze the fire hazards of liquids. Liquids having a flash point less than 37 degree Celsius are called flammable. While those having lower than the above mentioned temperatures are called combustible. iii. Cloud point and pour point The temperature at which the oil shows cloudiness is called cloud point. The temperature at which the oil stops flowing is called the pour point. This property tells the minimum temperature up to which the oil can be used. iv. Emulsification number It is the time required for a particular volume of oil to separate out in distinct layer from an equal volume of condensed steam under standard conditions. Good lubricating oil should form an emulsion that breaks off easily i.e. should have less steam EN. v. Aniline point The minimum equilibrium solution temperature for equal volumes of oil and aniline is termed as aniline point. Good lubricating oil has higher aniline point that indicates low percentage of aromatic …show more content…
MECHANISM OF ACTION OF LIQUID LUBRICANTS The liquid lubricants tend to lubricate via three important mechanisms: TABLE 4: CLASSIFICATION OF LUBRICATION MECHANISMS I. Thick film/ Fluid film/ Hydrodynamic lubrication As the name suggests, this mechanism of lubrication involves the introduction of a thick layer of the lubricating oil between the 2 surfaces that are in contact with one another. The thickness of the layer is about 1000 Angstroms. This results in minimum friction between the 2 surfaces and the coefficient of friction is low (0.001- 0.05). The hydrocarbon oils are preferred for this purpose. But the basic problem with such oils is that the viscosity of these oils decreases with an increase in the temperature. Thus to prevent this long chain polymers are added to the oil as they form their own cross links, thus preventing the oil to move. APPLICATIONS: It may be used in case of delicate instruments like watches, clocks, guns, sewing machines and scientific instruments. Fig 7: THICK FILM
He began experimenting with a cup that would regulate the flow of oil onto moving parts of industrial machines.
The total pressure of these two layers is the addition of the vapor pressure of each layer. Mixing these two layers results in a higher vapor pressure, which thus results in a lower boiling point than the boiling points of the water and the oil individually. Eugenol oil is the organic layer; therefore it is hydrophobic (afraid of water) and is nonpolar. This causes a boiling temperature that is slightly lower than 100 °C for the eugenol oil. Because eugenol oil has a lower boiling point than water, the molecule of eugenol is more likely to be able to escape into the air than the water, which has a higher boiling point.
A characteristic property can help identify a substance. A characteristic property will never change even when the volume of a substance is varied. A characteristic property also does not change when a substance changes state in matter. A physical property cannot identify a substance. A physical property will change when the volume of a substance is varied. It can also change when the substance changes state in matter. For example, if the volume and mass of a substance changes then the physical appearance will also change. However, the density, which is a characteristic property, will not change at all. The boiling point of a substance is the temperature that a substance changes from a liquid to a gas. The boiling point of a substance is a characteristic property because the boiling point of a substance will never change even when the volume and mass changes. The only thing that will change is the time that it takes to reach that temperature. If the mass and volume of the substance is small, then it will take a small amount of time for the substance to reach the temperature. However if the mass and volume of the substance is larger, then it will take a longer time to reach the temperature. The purpose of this lab was to see if when the volume of a substance changes so does the boiling point.
Any of a class of organic compounds that are fatty acids or their derivatives and are insoluble in water but soluble in organic solvents. They include many natural oils, waxes, and steroids.
At a constant temperature, a pure liquid has a vapor pressure that describes the pressure of escaped gaseous molecules that exist in equilibrium at the liquid’s surface. Adding energy to a pure liquid gives more molecules the kinetic energy to break the intermolecular forces maintaining the liquid and raises the overall temperature of the liquid. Eventually, adding energy boosts the liquid’s vapor pressure until it equals the surrounding atmospheric pressure. When this occurs, the pure liquid boils at a temperature called the boiling point.
However, low HLB surfactants may also be an important component of oral lipid-based formulation by behaving as a coupling agent for the high HLB surfactants and the lipophilic solvent components, as well as contributing to solubilization by remaining associated with the lipophilic solvent post-dispersion. Moreover, using a blend of high and low HLB surfactants may also lead to more rapid dispersion and finer emulsion droplet size upon addition to an aqueous phase [36, 48, 49, 51–55]. Thus, in this study, we decided to mix Tween 80 (high HLB value) with Carbitol (low HLB value) to identify the most effective combination emulsifying with three chosen oils. The size of the emulsion droplets decreased as the HLB value of surfactant mixture reached the required HLB (Table 2). In the case of soybean oil, the smallest size was 277 ± 2.49 nm obtained at 20:80 (v/v) ratio of Tween 80:Carbitol). In the cases of ethyl oleate (Tween 80:Carbitol, 90:10, v/v) and IPM (Tween 80:Carbitol, 60:40), the smallest droplet sizes were 2.9 ± 0.170 and 10.5 ± 0.596 nm, respectively. These results show that the combination of Tween 80 and Carbitol had extremely good emulsifying ability, resulting in a fine emulsion in the cases of using ethyl oleate and IPM oil. The results of the visual test (Fig. 1) are parallel to the results of droplet size measurements. The combinations that had a smaller droplet size of 100
Olefin/paraffin separation is very difficult to achieve because the molecules are similar in size and volatility. The relative volatility of propylene and propane mixture is 1.1 and that of ethylene and ethane is 1.5. Traditional
In which the graph is directly proportional to the volume and the temperature. As temperature increases, the volume increases, which exhibits a linear function. Therefore a linear equation can be made by using the two given points (85 (T1), 34 (V1 ) and (1 (T2), 29 (V2). By using the slope formula, the slope turn out to be 0.0595 mL/°C. From this the y and x intercept can derived from the slope when setting either x or y as zero to solve for the other. In this case, when x is one of the points such as 1 the y intercept can be solved to be 28.9. When setting y to zero and solving for x the value comes out to be -484(°C) which is the value in which the volume is 0. When comparing it to the actual absolute zero (-273.15°C) it is -77.2% off from the actual value in which the volume is suppose to be zero. At the end, the experiment correlated with Charles ' Law. This can be explained with water entering the test tube. In which lower temperature lowers the volume of the gas in the tube (water going in reducing the volume). When referring to absolute zero, it refers to 0 thermal energy, and in context scientists were able to cool down matter that is very close to this number but did not achieve absolute zero. For gases many factors that contribute on whether gas escape the atmosphere, this include the mass of gas, temperature, gravity, and planet size. The reason Charles ' Law uses the Kelvin scale
The viscosity of the corn syrup, measured in seconds it takes for an iron ball to move downwards in the fluid.
Oil- Is a liquid at room temperature and is generally comes from a plant origin.
Oil sands are unconventional petroleum deposits that consist of loose sand and partially consolidated sand stone that contains natural mixtures of natural clay, sand and water which is saturated with a highly viscous form of petroleum that flows extremely slowly known as bitumen (Yunchez, 2012).
Slime, has a different viscosity, based on the amount of strength you apply when playing with it. Slowly placing your hands on the slime is being described as a small amount of weight being applied to the slime, they will feel thin and water-like, letting you sink your hand into the jelly like substance. Punching it, or throwing it against a wall,
Surface Tension: The contractive tendency of a liquid that allows it to resist an external force. This is measured in Newton.
its state (Solid, liquid, gas); thus water has a higher melting point and a higher boiling
The oil refinery converts crude oil into valuable products and supplies. These products are made and sent to many countries abroad, in which are transported on land or along rivers and canals. Crude oil is then arranged and categorized into segments by fractional distillation. Raw crude oil, or unprocessed crude oil, is not normally beneficial in most industrial applications. Low sulfur crude oil has been valuable as a burner fuel to construct steam for the force of seagoing vessels. The lighter elements have the ability to construct explosive and dangerous vapors in the gas tanks. There are extremely hazardous, and are often used in war ships. The remaining hydrocarbon molecules are filtered from crude oil and used towards lubricants, feedstock, plastics, and fuels.