Requirements for Detection of parallel samples

1. UV. Determination of the content required for the test two, if the control method, the reference also requires two, the absorption coefficient method is also two. The deviation of each result from the average value is within 0.5%.

2. Atomic Absorption. In the case of a quantitative test, two aliquots are prepared for each test sample, three times for each injection. RSD should not be more than 3%, graphite furnace properly relaxed, large dispersion can be measured several times to increase the reliability of the reading. 3% here, I personally consider it a RSD requirement of three injections per sample instead of a parallel sample. I do not know what people think.

3. Fluorescence analysis. parallel samples need to be done, the results of the average deviation within ± 1.5%.

4. Melting point detection. Each test at least 3 repeated measurements, 3 readings within 0.5 degrees to poor. If the test three times the difference between exceeding 0.5 ℃, or the average margin in the edge, the need to re-test twice, according to the average of five times the correction value calculation results. Melting point standard to be measured twice, the difference is less than 0.3%.

5. Pour point. need to be measured twice, but no bias limit requirements.

6. Polarimetry. Determination of specific rotation than the same sample and the blank each measured three times, take the average. Determination of content required parallel samples, and two parallel samples within the range of 0.02 °.

7. Refraction. Requirements of the same sample and blank each measured three times.

8. Viscosity.

8.1 Ping Viscometer. Prepare two parallel samples each measured three times, and these three measurements shall not exceed the average value of 5%.

8.2 Rotary Viscometer. No requirement.

8.3 Ubbelohde Viscometer. Prepare two parallel samples each measured twice, and these two measurements shall not exceed 0.1S. The results for both samples do not exceed 1% of the average, if more than two additional retestings are required.

9. PH. Prepare a sample and measure it twice, with a difference of no more than 0.1

10. Non-aqueous titration. The test should be not less than 2 copies. The direct use of perchloric acid raw material titration, the relative deviation of not more than 0.2%. Alkali titration solution titration, the relative deviation of not more than 0.3%. Preparations need to be extracted or evaporated to dry titration, the relative deviation of not more than 0.5%. Such as extracting the washing operation is complex, the relative deviation of not more than 1.0%.

11. Nitrogen content. for the test sample should be determined 2 copies, the constant nitrogen relative deviation should not exceed 0.5%. Semi-trace nitrogen relative deviation of not more than 1.0%.

12. Determination of ethanol (gas phase method). two copies of the test, the relative average deviation of not more than 2.0%.

13. hydroxyl value, iodine value, saponification value. parallel determination of 2 parts, the relative deviation of not more than 0.3%.

14. acid value, peroxide value. only a measure.

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.

Capillary viscometer instructions

Description of glass capillary viscometer

Glass capillary viscometer to determine the liquid viscosity and polymer molecular weight of important instruments, the measurement range up to tens of thousands of centistokes (mm2 / S). Advantages are ease of use and accuracy compared to other types of viscometers. So widely used in petroleum industry, chemical industry, and other industrial and scientific research.

The Ubbelohde capillary viscometer produced by our factory conforms to the technical requirements stipulated by relevant national standards and ministry standards. In order to expand international exchanges, but also according to the specifications of IOS-3105 international standards for production, welcome to order.

Working glass capillary viscometer instructions for use 

Capillary viscometer by structure, shape can be divided into Ukrainian, Fen's, Ping's, counter-current four. The viscosity of the sample they measured was kinematic viscosity. Has been widely used in petroleum, chemical, light industry, mechanical and electrical, defense, transportation, coal, metallurgy, medicine, food, papermaking, textile, research, institutions of higher learning and other units. Correct use of capillary viscometer is important to ensure accurate product quality and scientific data.

(A) washing and drying

Before using the viscometer must be washed, the general first with solvent residue dissolved in the viscometer repeated washing, and then alcohol or gasoline wash, and then fuming sulfuric acid or potassium dichromate wash 2-3 hours immersion, Finally rinse with tap water, distilled water and rinse, into the oven, heating to 150oC or so, or in the natural temperature upside down for days, so far.

(B) loading: (except Uzbek directly into the thick tube from outside)

Use a rubber ball with a small mouth (earbuds) or syringe to attach the small glass tube to the thick tube, hold the viscometer in the left hand, and block the thick tube mouth with your index finger. Turn the viscometer upside down and place the long glass tube with capillary Into the sample, pull the syringe, the sample is drawn to the second coil (so that the liquid level and the coil tangent), and then erected. After the countercurrent is installed, clamp the latex tube with the clamp and wrap it on the pipe that sucks the sample.

(C) thermostat and transfer vertical

The sample is placed on a viscometer thermostat shelf (clip), the capillary left, right, before and after the vertical transfer, measured at a constant temperature of 10 minutes, began to measure, note the first to the second coil Between the outflow time, the general election line three times (removed not normal) take the average.

(D) available capillary diameter, sample viscosity range, refer to the following table: (selected viscometer sample outflow time of not less than 200 seconds)

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 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

Determination of Molecular Weight of Polyacrylamide by Dilute Solution Viscosity Method

Determination of Molecular Weight of Polyacrylamide by Dilute Solution Viscosity Method

Abstract: To learn and master the Ubbelohde viscometer viscosity measurement method; to understand the statistical significance of the molecular average molecular weight and polymer dilute solution of the intrinsic viscosity of the characterization method; master the determination of polymer dilute solution viscosity experiment Technology and viscosity method to characterize the molecular weight of polymer; the viscosity of polyacrylamide aqueous solution to reflect the molecular weight of polyacrylamide;

Experimental principle

        Liquid flow is due to external force molecules irreversible displacement process. Liquid molecules exist between the interaction force, so when the polymer liquid flow, the polymer molecules to produce internal friction between the performance of the liquid viscosity characteristics.

        According to Newton's law of viscous flow, the viscous resistance of the liquid to the flow is caused by the flow gradient between the two layers of flowing liquid (with A) due to intermolecular friction.

In the Ubbelohde viscometer capillary, it is assumed that the force that causes the polymer dilute solution to flow is all used to overcome the internal friction f:

For most flexible polymer - good dilute solution solvent system, protraction

with c and  with c. Extrapolated intercepts coincide with the value of the point

 , that is, the shape of the polymer is the polymer solution between the chain and the polymer solvent interaction between the molecules of the reaction, the current Mark-Houwink empirical formula:

Can be found in the relevant manual. Therefore, the polymer can be dilute the viscosity of the polymer to calculate the molecular weight.

Instrument: Ubbelohde viscometer constant temperature water bath, electronic scales, stopwatch, pipettes, flasks, ear cleaning ball, glass sand funnel;

Reagents: polyacrylamide samples, sodium chloride, purified water;

Experimental steps:

1. Solution preparation

2. Viscosity meter cleaning and drying

3. Viscometer installation: check the viscometer, with a clamp carefully fixed viscometer, into the constant temperature sink. The viscometer should be kept vertical, and the constant temperature surface should be immersed in the two balls above the capillary and the temperature remains constant.

4. Determine the elution time of the solution: Remove the 10 ml solution from the self-volumetric flask and inject it from the A tube into the viscometer. The clip holds the C tube and draws the solution from the B tube to the top of the a The ball volume of half of the time until the release of the ear ball, release the C tube clip, the air into the C tube, immediately horizontally watching the decline in the liquid level with a stopwatch recorded liquid flow through the a and b line time is Out of time.

5 ml, 5 ml, 10 ml and 10 ml of solvent were added to the same solution for 2/3, 1/2, 1/3, 1/4 of the original solution, and the respective elution times (t2, t3 , T4, t5).

Determination of pure solvent elution time: The solution in the viscometer was poured out and washed several times with solvent to determine the elution time t0 of the pure solvent.

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

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

Coyp right by @Hangzhou Zhongwang Technology CO.,LTD

Determination Liquid viscosity determination at different temperatures

Determination Liquid viscosity determination at different temperatures

Abstract: to understand the principle of the thermostatic bath, structure and function of each component, learn to adjust the thermostat. Understand the significance of liquid viscosity and the principle and method of measuring viscosity. Determination of viscosity of ethanol at different temperatures by Ubbelohde viscometer, calculate the activation energy of ethanol flow.

1.      Constant temperature technology:

A thermostatic bath commonly used in laboratory is a common temperature control device. The basic principle is that when the bath temperature is lower than the set temperature, it heating automatically; when the bath bath temperature is higher than the set temperature, stop heating automatically, and automatically depending on the situation. As a result, the temperature fluctuates in a small range, and the system is confined to the required temperature at very small intervals under the constant temperature water.

2. Determination of liquid viscosity:

All the liquid have viscosity, it can be represented by a viscous coefficient η. η has the relationship with the molecular size, shape, and composition of liquid molecular force. In this experiment, the viscosity of liquid is measured by capillary outflow method. Under certain temperature by Poiseuille formula PI ETA = r4pt/ (8LV). The international system of η units is ETA Pa * s, 1P=0.1Pa * s. Usually use two kinds of liquid viscosity formula for doing business. That is η2=η1×p2t2/p1t1

The temperature changes of the intermolecular force , viscosity also changed.The relationship are η=Aexp(Evis/RT) or Inη=InA+Evis/RT.
 Among them, Evis is called liquid flow activation energy, to In on the 1/T map in a straight line, the slope of S=Evis/R,so Evis=SR.

Operation procedure of viscosity test:

1. Switch on the constant temperature sink power supply, turn on the switch, set the temperature for the experiment temperature, wait for the water temperature to the set temperature and keep stable.

2. Determination of 25 degree ethanol through Ubbelohde viscometer capillary time. Clamp the tube on the C tube with a clamp to absorb the gas. Draw the ethanol from the D ball, capillary, and E ball to the G ball. Step B tube of latex tube, remove the C tube clip, at this time, D ball part of ethanol flow back to the F ball, D ball through the C tube and atmospheric communication, capillary end that the atmosphere. The B pipe clamp is removed and the ethanol falls in the B tube. When the liquid level flows through the scale a, the stopwatch is started and the time is stopped when the liquid level drops to B. This time is the time between the AB and the volume of V ethanol flowing through the capillary tube ta. Repeat operation 2~3 times, each difference is not more than 0.5s, take the average.

3. Increase the temperature 3 degrees, ibid., the 2 step, determine the temperature of ethanol flow through the capillary tube, so measured 4~5 data.

4. After measuring, turn off the thermostat, the switch and the agitation tank switch, disconnect the power supply, and return the instrument, ear ball and stopwatch.

Experimental raw data

Number	1		2		3		4
T/℃	28		31		34		37
ρ/g×cm-3	0.78267		0.78		0.77756		0.775
t/s	a	b	a	b	a	b	a	b
	306.44	306.68	294.47	296.9	275.18	277.87	266.25	265.5

When T = 28 ° C, the viscosity of ethanol is η1 = 1.015 mPa × s

The activation energy of anhydrous ethanol was found to be 13.40 kj / mol

Experimental Data Processing and Results Discussion:

From the formula η1 / η2 = p1t1 / p2t2, and the viscosity of ethanol η1 = 1.015mPa × s can be obtained at different temperatures viscosity, as shown in the table below:

1/(T/K-1)	3.32×10-3	3.28×10-3	3.26×10-3	3.22×10-3
In(η/mPa×s)	0.0149	-0.0243	-0.0943	-0.138

Make Inη—1/T chart

Takes on the straight line A (0.00331, -0.001), B (0.00324, -0.109) two points, find the slope S = (0.001-0.109) / (0.00324-0.00331) = 1.54 × 103K

             Evis = RS = 8.31 x 1.54 x 103 KJ / mol = 12.80 KJ / mol

   The relative error E = | Evis-Evis true | / Evis true × 100% = | (12.8-13.4) /13.4|×100%=4.47%

Experimental error analysis:

1. viscometer can not be guaranteed when placed completely straight, resulting in a certain error;

2. with a stopwatch time, because the stopwatch itself is not accurate enough, will cause some error, and in the stopwatch may appear even when the phenomenon, so that measurement is not allowed;

3. because in the observation of the liquid surface, in the a and b line to determine the standard can not be exactly the same, resulting in a certain error.

Note:

1. viscometer must be placed as far as possible;

2. with the suction ball to absorb the liquid, the liquid may not be mixed with bubbles, or should be exhausted in order to be able to experiment;

3. if the operation to contact B tube or C tube should be particularly careful, because the B tube or C tube has a longer arm, the force is small but the formation of a larger torque, easy to break at the interface between the tube;

4. viscometer can not water, should ensure that the purity of the tube ethanol.

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

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

Coyp right by @Hangzhou Zhongwang Technology CO.,LTD