SOP for UBBELOHDE Viscometer

Bottle Grade PET Resin in Solution Instrinsic Viscosity Testing by Capillary Ubbelohde Viscometer

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Glass Capillary Viscometers (Viscometer accessories)

The principle of capillary viscometer

A viscometer based on Hagen Poisson's (Hagen-Poisculli) rule is obtained by measuring the flow rate of fluid flowing through the capillary, the pressure difference between the capillary outlet and the inlet, and then according to Hagen Poisson's law.

Capillary viscometer

A viscometer based on Hagen Poisson's (Hagen-Poisculli) rule is obtained by measuring the flow rate of fluid flowing through the capillary, the pressure difference between the capillary outlet and the inlet, and then according to Hagen Poisson's law.

Hagen - bershaw leaf formula:

ETA = (n R^4Pt) /8VL

Among them:

V--t time flows through the capillary volume

R-- capillary radius

P-- capillary pressure difference at the end of two

L-- capillary length

As long as the volume, time and pressure added to the liquid are obtained, the viscosity of the liquid can be reversed.

There are three main types of capillary viscometer: round - piston, glass tube and pass viscometer. The circular hole - piston viscometer allows for greater pressure, so it can be used to determine the viscosity of the polymer.

The pore type viscometer is also called the short tube type, and the small pore type can be used for rough measurement and viscosity comparison of Newtonian fluid. Glass tube type viscosity and wide application, can be divided into gravity type and pressure type. The gravity type is generally used to measure the Newton fluid, and the pressure type can be used to measure the non Newton fluid. There are many kinds of glass capillary viscometer, most of which are named by the designer's name abroad. The methods of their construction and use are all the same.

Polylactic acid PLA molecular weight and intrinsic viscosity

Polylactic acid, also known as polylactide, belongs to the polyester family. Polylactic acid is a polymer obtained by polymerization of lactic acid as a main raw material, and the raw materials are abundant and can be regenerated. Polylactic acid production process pollution-free, but also biodegradable products to achieve in the nature of the cycle, it is the ideal green polymer materials.

Polylactic acid (H- [OCHCH3CO] n-OH) thermal stability, processing temperature 170 ~ 230 ℃, good solvent resistance, can be processed by a variety of ways, such as extrusion, spinning, biaxial stretching , Injection blow molding. In addition to biodegradable products made of polylactic acid, biocompatibility, gloss, transparency, feel and heat resistance, polylactic acid (PLA) developed by Brilliance Albert also has some antibacterial, flame retardant It is used in a wide range of applications as packaging materials, fibers and nonwovens. It is mainly used in garments (underwear, garments), industry (construction, agriculture, forestry, paper making) and healthcare.

PLA molecular weight and viscosity (experimental results for reference only)

① Mn = 55872η1.2967 → η = 2.18 × 10-4Mη0.77

② Mw = 264911η1.7519 → η = 8.03 × 10-4 Mw0.57

③ Mn = 126911η1.6982 → η = 9.88 × 10-4Mn0.59

④ Mz = 472515η1.7836 → η = 6.59 × 10-4Mz0.56

⑤Mz + 1 = 670038η1.7453 → η = 4.59 × 10-4 Mz + 10.57

Where: η is the viscosity;

Mη is the viscosity average molecular weight;

Mw is the weight average molecular weight;

Mn is the number average molecular weight;

Mz is Z average molecular weight;

Mz + 1 is the Z + 1 average molecular weight.

Kent Yuan (Mr.) Hangzhou Zhongwang Technology Co., LTD. Skype: kenyuan9023   Wechat/WhatsApp:+86 15068109723E lei@zonwon.com  W www.zonwontech.com

Ubbelohde viscometer diameter and applicable solvent list

Capillary diameter mm: 0.37; Applicable solvents: Dioxane

Capillary diameter mm: 0.38; Applicable solvent: chloroform

Capillary diameter mm: 0.39; Applicable solvents: acetone

Capillary diameter mm: 0.41; Applicable solvent: ethyl acetate

Capillary diameter mm: 0.46; Applicable solvents: Ding Ding acetate, acetone (1: 1

Capillary diameter mm: 0.47; Applicable solvent: tetrahydrofuran

Capillary diameter mm: 0.48; Applicable solvents: n-heptane

Capillary diameter mm: 0.49; Applicable solvents: dichloroethane, toluene

Capillary diameter mm: 0.54; Applicable solvents: chlorobenzene, benzene, methanol, p-xylene, n-octane

Capillary diameter mm: 0.55; Applicable solvents: butyl acetate;

Capillary diameter mm: 0.57; Applicable solvents: dimethylformamide, water;

Capillary diameter mm: 0.59; Applicable solvents: dimethylacetamide;

Capillary diameter mm: 0.61; Applicable solvents: cyclohexane, dioxane

Capillary diameter mm: 0.64; Applicable solvents: ethanol;

Capillary diameter mm: 0.66; Applicable solvents: nitrobenzene

Capillary diameter mm: 0.705; Applicable solvents: cyclohexanone

Capillary diameter mm: 0.78; Applicable solvents: o-chlorophenol, n-butanol

Capillary diameter mm: 0.80; Applicable solvents: phenol, tetrachloroethane 1: 1;

Capillary diameter mm: 1.07; Applicable solvent: m-cresol

Tags: viscometerviscosityviscosmeterubbelohde viscometermolecular weight

Using Ubbelohde viscometer to measure the molecular weight of polyacrylamide

Test Method: Use 85g / L sodium nitrate solution will be configured as a dilute solution sample, with Ubbelohde viscometer to determine the ultimate viscosity, according to empirical formula to calculate the molecular weight of the sample.

Reagent solution: 85g / L sodium nitrate solution

Equipment: Ubbelohde viscometer (capillary diameter 0.55mm)

Constant temperature water bath (can control 30 ℃ ± 0.1 ℃)

Stopwatch (division 0.1s)

Acid filtration funnel

The company is located in:

Experimental steps:

1. Determination of sodium nitrate solution outflow time

The clean, dry Ubbelohde viscometer vertically placed 30 ℃ ± 0.1 ℃ constant temperature water bath so that the U-viscometer D ball all submerged under the water.

Will be filtered through acid filtration funnel sodium nitrate solution was added to the Ubbelohde viscometer filling line between G, so far, constant temperature 10min-15min.

M tube set a hose, with the clip, use the ear ball to the sodium nitrate solution into the D ball half, remove the ear wash ball, open the M tube.

Measure the time it takes for the sodium nitrate solution to flow through the timed markers E, F with a stop watch. Repeated determination of three times, the error does not exceed 0.2s, whichever is the average t0.

2. Preparation of sample solution

Weigh 0.03 g of solid sample or equivalent amount of colloidal sample from a known 50 mL dry beaker to the nearest 0.2 mg and dissolve with sodium nitrate solution. All transferred to 100mL volumetric flask, diluted with sodium nitrate solution to the mark, shake.

3. Determine the outflow time of the sample solution

The outflow time t1 of the sample solution is determined by the first step method

4. Calculate the result according to the formula

Kent Yuan (Mr.) Hangzhou Zhongwang Technology Co., LTD. Skype: kenyuan9023   Wechat/WhatsApp:+86 15068109723E lei@zonwon.com  W www.zonwontech.com

Using Ubbelohde viscometer one-point method to determine the intrinsic viscosity

Material: a triangular flask

Two 10ml pipettes

Ubbelohde viscometer (capillary 0.5mm)

A water bath (temperature control accuracy of ± 0.1 ℃)

A stopwatch

Rubber hose two sections

A syringe

Wash the ear ball one

The company is located in:

step:

1, the system solution: Take a certain amount of polymer, add 10mm solvent, make it completely dissolved, if necessary, heated.

2, constant temperature: installed device, stable temperature up and down changes 0.1 ℃.

3, plus the solution balance 5min: up and down into the capillary tube three times.

4, determination: measured three sets of data, so that the deviation but 0.2s.

5, Determination of solvent flow time.

data processing:

ηr = t / t0 (t is the solution flow time, t0 solvent time)

ηsp = ηr-1

[η] = [2 (ηsp-ηr)] / C (C is the concentration unit g / ml)

[η] = (ηSP / C) c = 0 = (ln ηr / C) c = 0 [η] = KMα

Remove the pipette has been pre-heated solution 10ml, into the viscometer, the same method, the installation of viscometer, the determination of the solution outflow time t. Then followed by adding 2.00,3.00,5.00,10.00 ml of distilled water.

Kent Yuan (Mr.) Hangzhou Zhongwang Technology Co., LTD. Skype: kenyuan9023   Wechat/WhatsApp:+86 15068109723E lei@zonwon.com  W www.zonwontech.com

Introduction and influencing factors of kinematic viscosity determination of petroleum products

Scope of application

The petroleum product movement tester is designed and manufactured according to the national standard GB/T265. It is used to measure the kinematic viscosity of liquid petroleum products. LCD screen Chinese display, man-machine dialogue interface, preset temperature, test time and other parameters menu prompt input, appearance design is beautiful, is the introduction of new instruments.

Viscosity is one of the main indexes of petroleum products, and viscosity is one of the important factors that affect the biodegradability of base oils. Many domestic lubricants are classified and classified according to their kinematic viscosity of 40oC and 100oC. In practical application, viscosity is an important index to evaluate the flow performance of lubricating oil. It is important for quality identification of petroleum products and their application. Viscosity is large, oil film thickness is large, lubrication performance is good, but the viscosity is too large, will increase the friction resistance, waste of resources.

Kinematic viscosity is the ratio of the dynamic viscosity of a liquid to its density at the same temperature. It represents a measure of the friction of a liquid when it flows under gravity. Kinematic viscosity measurement is the determination of the time at which a certain volume of liquid passes through a calibrated glass capillary viscometer at a constant temperature. The product of the capillary constant and flow time, i.e., the kinematic viscosity of the liquid at this temperature.

Functional characteristics

1. ring type fluorescent lamp illumination, fluoroscopy is good. Easily observed.

2. heater and guide tube and bath parts are made of stainless steel, durable and durable.

3. Automatically calculate the capillary constant and the average product of the test time. The temperature control precision is high and the accuracy is good.

4, computer temperature control, timing, constant temperature, water bath and other parts. Constant temperature bath is small cylinder, round cylinder, double layer, uniform temperature distribution in the bath, the temperature control effect is good.

5. Chinese LCD screen display, man-machine interface, the preset temperature, test time and other parameters, menu input, actuator adopts advanced SSR, its features of no contact, no spark, no action noise, vibration resistance, long life.

Technical parameter:

1, weight: 25kg

2, constant temperature accuracy: + 0.1

3, the number of cards installed capillary: 3 branches

4 ,heater power: 1000W

5, environmental temperature: room temperature to 35 degrees

6, temperature control settings: room temperature to 100 degrees set at any time

7, work power supply: 220V + 10% 50Hz

The main factors influencing the determination of kinematic viscosity:

First, the measurement of the factors:

1. Stopwatch: The stopwatch is used to determine the time the sample flows through the viscometer. If the stopwatch is not precise enough, it may cause a test error. Therefore, for the use of the stopwatch, be sure to regularly test.

2. viscometer coefficient: capillary viscometer must be calibrated on a regular basis, otherwise it will cause a greater error.

Second, the experimental operation of the factors

1, the viscosity of the process of measuring the flow of oil through the viscometer

The flow time of the specimen must be within the specified range. GB / T265 provides that the flow time to> 200S. Mainly in order to ensure that the oil flow in the viscometer for the laminar flow. If the oil flow rate is too fast beyond the specified range, will become turbulent, with turbulence can not use the cassace equation to calculate the viscosity of oil. In addition, the flow rate is too fast, the reading error will increase accordingly. If the oil flow rate is too slow, within a specified time is not easy to maintain constant temperature

2, the viscosity of the test process bath temperature accuracy

Determination of kinematic viscosity to be strictly in accordance with the provisions of constant temperature test, which is the determination of oil moving viscosity of one of the important conditions. In GB / T265, the temperature control accuracy of the thermostatic bath must be ± 1oC, while in the ASTMD445 bath temperature control accuracy of ± 0.5oC. Because the viscosity of the oil sample decreases with increasing temperature and increases with the temperature drop, it must be strictly in accordance with the specified constant temperature, the slight temperature deviation will make the viscosity measurement results have a greater error.

Third, the viscosity of the other factors in the determination process

Test oil samples containing impurities, moisture and capillary viscometer is not washed, will also affect the sample in the capillary viscometer in the normal flow, the results are high. The solvent used for the washing in the viscometer is not dry and the sample is diluted so that the result is low.

When measuring the viscosity of the oil, the sample in the viscometer can not have air bubbles. If the oil bubbles will affect the oil volume, while entering the capillary will form a gas plug, so that the flow resistance of oil increased, the determination of high results.

Kent Yuan (Mr.) Hangzhou Zhongwang Technology Co., LTD.

P  /Wahtsapp: +86 15068109723  E lei@zonwon.com

Influence of Test Temperature on Polyester Chips Viscosity

Influence of Test Temperature on Polyester Chips Viscosity

Abstract: Testing result indicates that polyester chips viscosity are very sensitive to the test temperature. So it requires to control the temperature precision range strictly . Therefore, an ideal constant temperature water bath is necessary to get the reliable result of the viscosity.

Polyester resin in the field of polymer occupy a leading position, it is not only high strength, good heat resistance, non-toxic, and good insulation. By different processing means, it can be made in the film, in the audio and video tapes, lighting film, food packaging, for high-strength composite film, and can be processed into different types of beverage bottles and electrical parts. Polyester chips are also important raw materials for the chemical fiber industry. Spinning polyester chips must maintain a high purity. So the inspection department to each batch of products to conduct a series of performance indicators to ensure the quality of the batch. The viscosity index indirectly represents the size of the molecular weight, which directly affects the quality of the finished polyester yarn, and the test temperature is particularly sensitive to the viscosity, so the required test temperature range must be strictly controlled.

Polyester chips are specified in the relevant standard method by dissolving one or two mixed solvents at a certain temperature to a certain concentration and then measuring the solvent at a specified test temperature by an Ubbelohde viscometer (having a defined capillary diameter) And the time the solution flows, converted into relative viscosity and intrinsic viscosity. ASTMD2857 specified test temperature accuracy of ± 0.01 ~ 0.02 ℃, ISO12228 specified test temperature accuracy of ± 0.05 ℃, China is the national standard in principle to the ISO closer to the set, also set to ± 0.05 ℃

Select the Taiwan polyester chips (contract, the intrinsic viscosity IV0.645 ± 0.015) set the temperature of the thermostat different temperature for the test to observe the changes in viscosity:

1. Test conditions

Solvent: mixed solvent, weight ratio of phenol: tetrachloroethane = 3: 2

Solution concentration: 0.5%

Test temperature: 25.00 ~ 25.08 ℃

2. Accuracy measurement at different temperatures

Table 1 Effect of temperature on the determination of PET slice adhesion

The same time as

Test temperature ° C Relative viscosity Viscosity

25.00  1.363  0.645

25.01  1.363  0.645

25.02  1.360  0.641

25.05  1.355  0.634

25.08  1.350  0.625

From the data of Table 1, the intrinsic viscosity value decreases with increasing temperature, the temperature rises by 0.01 ℃ Viscosity is not affected; the temperature rises 0.02 ℃, the intrinsic viscosity decreases 0.004; when the temperature rises to 0.05 ℃, the intrinsic viscosity decreases 0.011; To 0.08 ℃, the intrinsic viscosity dropped to 0.021, has been outside the scope of the contract. This shows that the temperature parameters directly affect the size of the viscosity, it is necessary to strictly control the temperature accuracy range, the determination of the results can be a reliable guarantee.

3. Need to pay attention to the problem

Determination of viscosity method is not complicated, but in order to ensure the correctness of the test results must be strictly to the various test links, try to avoid errors. This is mainly: ① weighing; ② solution preparation; ③ viscometer cleaning; ④ viscosity determination of the viscosity of the vertical degree; ⑤ visual line when the level of the situation; ⑥ timer press speed; ⑦ constant temperature water bath temperature The

Among them, the constant temperature water bath temperature control accuracy is determined by the thermostat, and the visual line of the error is also determined by the thermostat, especially those observation window for the arc when the marking line blurred, the greater the error. In addition, it is almost entirely determined by the quality of the inspectors. Therefore, the configuration of an ideal precision constant temperature water bath is a guarantee of an important device for viscosity determination.

The same time as

At present, the domestic production of the thermostat groove accuracy is rarely higher than ± 0.05 ℃, roughly, seems to meet some of the international standards and the implementation of the new national standard, but in fact, due to uneven temperature distribution throughout the tank, With the temperature control temperature fluctuations, the overall control accuracy is clearly inferior to 0.05 ℃, especially in the factory application, a number of viscometer placed in different locations, this phenomenon even more directly affect the test data, while , The thermostatic bath with the refrigeration system is far from being extended, and the viscosity test also brings a lot of trouble (generally, there is no cooling system of the thermostat, only when the room temperature is lower than the test temperature of 5 ℃, to ensure that the temperature control Precision).

What is the true 0.01 ° C temperature control accuracy?

The same time as after adjusting the temperature of the thermostat, from today to tomorrow, the temperature changes, not more than 0.01 ℃, and the temperature inside the thermostat tank temperature distribution is poor, not more than 0.01 ℃.

Kent Yuan (Mr.) Hangzhou Zhongwang Technology Co., LTD.

P  /Wahtsapp: +86 15068109723  E lei@zonwon.com