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

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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

K, α value of Some Common Polymer

K, α value of Some Common Polymer 

Abstract:

Polymer, Polymerization Method, Molecular Weight Range, Solvent Temperature K Value, Polystyrene (PS) Solution Polymerization 3-1700 Toluene 25 ° C 1.7 0.69 1-11 Benzene 25 ° C 4.17 0.60 5.9-5.2 Benzene 20 ° C 1.23 0.72 330-Benzene 30 ° C 1.1 0.73 polymethylmethacrylate bulk polymerization 70-6300 benzene 25 ° C 0.468 0.77 (PMMA) 240-4500 benzene 25 ° C 0.38 0.70 emulsion polymerization 410-3400 acetone 25 ° C 0.96 0.69 410-3400 toluene 25 ° C 0.71 0.73 410-3400 Chloroform 25 ° C 0.34 0.83 styrene-butadiene rubber (SBR) emulsion polymerization 25-500 toluene 25 ° C 5.25 0.66 emulsion polymerization 50 ° C 26-1740 toluene 30 ° C 1.65 0.73 emulsion polymerization 5 ° C 55-1000 toluene 30 ° C 2.95 0.75 natural rubber (NR) 0

Polymer	Polymerization Method	Molecular Weight Range	Solvent	Temperature	K Value	α Value
Polystyrene (PS)	solution polymerization	3-1700	Toluene	25 ° C	1.7	0.69
		1-11	benzene	25 °C	4.17	0.60
		5.9-5.2	benzene	20 ° C	1.23	0.72
		330-	benzene	30 ° C	1.1	0.73
Poly (methyl methacrylate) （PMMA）	Polymerization	70-6300	Benzene	25 ° C	0.468	0.77
		240-4500	benzene	25 ° C	0.38	0.70
	Emulsion Polymerization	410-3400	Acetone	25 ° C	0.96	0.69
		410-3400	Toluene	25 ° C	0.71	0.73
		410-3400	Chloroform	25 ° C	0.34	0.83
Styrene-butadiene rubber (SBR)	emulsion polymerization	25-500	Toluene	25 ° C	5.25	0.66
	Emulsion Polymerization 50 ° C	26-1740	Toluene	30 ° C	1.65	0.73
	Emulsion Polymerization 5 ° C	55-1000	Toluene	30 ° C	2.95	0.75
Natural rubber (NR)		0.4-1500	Benzene	25 ° C	5.02	0.17
Butadiene rubber (BR)		20-1300	Toluene	25 ° C	2.15	0.65
		26-660	Butanone	30 ° C	4.8	0.55
Polyacrylonitrile (PAN)		48-270	Dimethylformamide	25 ° C	1.66	0.81
Polyester (PET)		3-370	Dimethylformamide	25 ° C	2.33	0.75
		12-28	Phosphorus Chlorobenzene	25 ° C	3.0	0.77
		5-25	phenol / tetrachloroethane	25 ° C	2.1	0.82
Polyvinyl alcohol (PVA)		11.6-195	Water	25 ° C	5.95	0.63
		44-1100	Water	50 ℃	5.9	0.67
		30-120	Water	30 ℃	6.6	0.64

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 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