Using method and application of Ubbelohde viscometer

Using method and application of Ubbelohde viscometer

Abstract: the viscosity coefficient of liquids, referred to as viscosity, reflects the size of the frictional force in the fluid, i.e., the magnitude viscosity of the fluid. This article describes the research method of using Ubbelohde viscometer fluid viscosity measurement size and application.

The molar mass of polymers not only reflects the size of polymer molecules, but also directly relates to their physical properties. It is an important but basic parameter. Unlike common inorganic or low molecular organic compounds, polymers are mostly mixtures of macromolecules of different molar masses, so the molar mass of a polymer is usually a statistical average.

There are many methods to determination of high molar mass, while the average molar mass obtained by different methods are also different. By comparison, the viscosity method is simple, easy to operate and has very good experimental accuracy. It is one of the most common methods. With the method of molar mass is called viscosity average molar mass.

Using method of Ubbelohde viscometer

1.     Take out the Ubbelohde viscometer, with a solution made of certain concentration in accordance with the provisions of the rules, and go through with a 3 sintered glass funnel filtration, discarding the initial filtrate (about 1ml);

2.     The successive filtrate (not less than 7ml) along the dry and clean Ubbelohde viscometer  2 wall into B tube, the viscometer is vertically fixed on the constant temperature water bath (bath temperature should be 25 - 0.05 DEG C unless otherwise specified), and make the water level higher than the ball C, placed in 15 minutes;

3.     The nozzle 1 and 3 are respectively connected with a latex tube, pipe clamp 1 hose, since the nozzle 3 pumping, the tested liquid solution slowly increased to the ball the central C, first open the orifice 3, then open mouth 1, the testsolution in tube falling, with a stopwatch accurate record the level of m<[1]> decreased to self testing fixed line by line m<[2]> at the outflow time;

4.     Repeated determination of two times, two times the difference between the value of determination shall not exceed 0.1 seconds, averaged two times for the test solution outflow time (T).

5.     learn from the No. 3 vertical molten glass funnel filtration solvent, the same operation, repeated determination two times, two times the measured value should be the same, for the solvent outflow time (T<[0]>), according to formula to calculate the intrinsic viscosity.

Study on Application of Ubbelohde viscometer

1. Molecular weight determination:

Because the specific viscosity is closely related to the viscosity average molecular weight of polymers, the intrinsic viscosity is a very important molecular weight parameter

Analysis of the morphology

2. Polymers in solution:

Polymer in different solvents, due to different degrees of expansion, so that the value of its intrinsic viscosity is different, batch difference can reach as much as 5 times. According to the characteristics of viscosity in different solvents, we can determine the initial conformation of the polymer in a solvent, especially some biopolymer, this phenomenon is very obvious

3. Criteria for the degree of polymer synthesis

When the polymer is polymerized by solution polymerization, the concentration of the solution increases as the degree of polymerization of the polymer increases. Therefore, in the experimental process of the synthesis of the polymer solution, can be in different stages of sampling, determination of kinematic viscosity solution by Ubbelohde viscometer, used as a criterion of polymerization degree.

4. Kinetic study of polymerization

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

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