SU377674A1 - DEVICE FOR DETERMINATION OF THE MOLECULAR-WEIGHT DISTRIBUTION OF POLYMERS - Google Patents

Description

one

The invention relates to the field of determining the molecular weight distribution (MBR) of polymers.

Instruments for determining the molecular weight distribution of polymers are known, containing a cuvette with a polymer to be tested, an optical-electronic system for measuring the intensity of light scattering with an illuminator and a photo-receiver, a device for planting a polymer, and an automatic recorder.

Automation of the process of analytical fractionation of the polymer is ensured by the fact that the device for planting the polymer is made in the form of an electric heater connected to the output of the autotransformer located at the periphery, and the photodetector of the optical-electronic system is angled to the direction of the light flux.

The drawing shows the proposed device.

The device consists of a cuvette / with the studied polymer 2; thermocouples 2, the cold layer of which is lowered into the dewar 5; an optoelectronic system for measuring the intensity of the scattering of light containing a stabilized power source 4, a step-down transformer 5, an illuminator 6, a photodetector 7, and an amplifier 8; a device for planting a polymer comprising a cylinder 9, an electric heater 10, an autotransformer //, a sliding contact 12 and a synchronous motor 13; magnetic thumbwalker 14 and automatic recorder / 5.

The operation on the instrument is carried out as follows.

The test material is placed in a cuvette /, the thermocouple 2 is inserted and placed in

cylinder 9. After that, the device is switched on to the AC network. The stabilized voltage from the power source 4 is supplied to the photodetector 7 and the amplifier 8, and through the step-down transformer 5 to the illuminator 6.

First, the solution of the polymer under study is heated to a temperature at which the polymer completely dissolves. Then include a synchronous motor 13, which

controls the movement of the sliding contact 12 of the autotransformer 11. The electric heater 10 is supplied with a voltage varying according to a given law, as a result of which the temperature in the cuvette changes.

Changes in polymer temperature will be recorded using a thermocouple 2 on an automatic recorder 15.

The polymer solution is transported by means of a magnetic messenger 14.

When the polymer fractions are deposited, the light beam from the illuminator, the passage through the solution, is recorded by the photodetector, the change in the intensity of the light beam characterizes the concentration of the precipitated polymer, which is also recorded. The automatic recorder 15 records data on the change in the intensity of the light beam.

Thus, the molecular weight distribution of the polymer is automatically recorded.

Subject invention

Claims (2)

1. A device for determining the molecular weight distribution of polymers, containing a cuvette with the polymer under test, an optical-electronic system for measuring the intensity of light scattering with an illuminator and photodetector, a device for planting polymer, and an automatic recorder, characterized in that in order to carry out the automation of the fractionation process , the device for planting the polymer is made in the form of an electric heater located at the periphery of the cuvette, connected to the output of the autotransformer. 2. The apparatus according to claim 1, characterized in that the photodetector of the optoelectronic system is located at an angle to the direction of the light flux.