SOP for UBBELOHDE Viscometer

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

Determination Intrinsic Viscosity of ACR

Determination Intrinsic Viscosity of ACR

First, equipment and auxiliary equipment

① Φ0.56mm a Ukrainian viscometer

② a set of automatic viscometer (25 ℃ ± 0.01 ℃)

③ 3 # sand core funnel 3 (covered)

④ conical flask 3

⑤ 75ml volumetric flask 3

Second, reagents: analytical grade (chloroform), content ≥ 99.0%

Third, the intrinsic viscosity of the sample test: 1, configuration solution 2, measured viscosity

1, configure the solution

① measuring bottle logo: the required capacity of 75ml three bottles (should be kept dry) clearly identified by the number.

Note: High viscosity is used separately from the volumetric flask used for low viscosity samples.

② balance calibration: Calibrate the balance, adjust the level (adjust the bottom of the balance knob so bubbles in the middle of the circle), with 200 grams weight calibration;

When adjusting the balance, or weighing, you should close the doors, windows, etc., at the same time shut down the balance door to prevent the wind from affecting the balance. When weighing, the balance can be read after the number of stable, prohibit the balance of data beating larger than reading.

 '¢ with liquid: open in Wang automatic dosing device DP25 and the DP25 and electronic scales connected to the sample bottle into the electronic balance and add 0.075g ± 0.01 ɡ expected in the automatic dial-up device DP25 touch screen settings The required concentration of 0.003g / ml, click the dosing button to complete dosing.

④ Sample Dissolution: Place the sample bottle containing the concentration solution in P12, and set the sample-dissolving time. The sample is dissolved automatically by P12.

2, Viscosity Testing:

① open the viscosity of the instrument set sink temperature 25 ℃ (Chung Mong Intelligent Viscosity Measurement System IVS300 series temperature control accuracy of ± 0.01 ℃), to be stable after the temperature field into the chloroform solvent with Ubbelohde viscometer (with basket) Click the start test, the system will automatically complete the continuous test and remove the unqualified data, get T0; the same way to measure the sample solution Flow time t.

② measure the t value of other bottles: the same way to measure the viscosity of the remaining two samples (tools can not be mixed).

③ by the viscosity of the software obtained in the sample viscosity of the sample solution.

Fourth, tool cleaning:

① Ubbelohde viscometer after use, the amount of chloroform 50ml beaker to take 25ml of chloroform added to the viscometer, use the ear wash up, then blow down, repeated three times (Note viscometer is not allowed to use water scouring, if water enters Should be dry), Ubbelohde viscometer upside down in the folder after the clip on the butterfly.

② volumetric flask and sand funnel were washed, with a 50ml beaker to take 25ml of chloroform into the volumetric flask, and then repeatedly shaken several times; sand funnel also 25ml chloroform wash shampoo, then wash the ear ball from the mouth Blowing out the waste a few times; Erlenmeyer flask with chloroform.

Note: All waste liquid into the waste collection bottle, warehousing unified treatment, after cleaning, measuring flask, sand funnel inverted placed in the tool plate, rack.

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

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