Viscometers for the study of polymer photodegradation in solutions

The kinetics of polymer photodegradation in solutions can be studied by measuring the change in solution viscosity during irradiation (cf. section 10.9). 

The following procedure is followed in order to carry out measurements in an inert gas atmosphere or in the vapour of a solvent  

The viscometer is connected to an efficient evacuation device (10 -10 mmHg)  

The polymer solution in the viscometer is cooled to its freezing point by liquid air or by a cooling mixture  

The evacuation line is cut off and the solution in the viscometer is thawed to expel air from the solution into the evacuated space  

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