Polymerisation kinetics by gel permeation chromatography GPC

It may happen that the properties of a monomer and its oligomers and polymers are so similar that they cannot be separated by precipitation that in the appropriate solvents the reaction mixture gels, so that dilatometry cannot be used that it becomes so opaque that neither refractive index nor optical rotation can be determined and that the reaction is too slow for normal reaction calorimetry. This situation was met when the author attempted to study the polymerisation of trimethyl and tribenzyl laevo- 

The principle is this A reaction mixture is made up and distributed into breakable phials. These are thermostatted, broken at noted times into a neutralising solution, and the mixture analysed immediately by GPC. This was done in the apparatus shown in Fig. 5.10 as follows. 

The ampoule A was charged with the crystalline monomer, a phial P of initiator (e g. PFj solution), and a magnetic breaker M and then sealed at B to the rest of the rig which was then evacuated. Methylene chloride was distilled in from a reservoir on the vacuum line to dissolve the monomer and was then pumped off slowly, and evacuation was continued for 8 h, which process produced an efficient final drying. The purpose of the two pumping ducts C and D is to circumvent the evacuation obstacle presented by the sintered filter S. The required volume of solvent was then distilled into A, the rig sealed off from the line at E, and the ampoule A brought to the right 

It was found unnecessary to remove solvent, initiator and neutralising agent before the GPC analysis. Evidently, this method is applicable to any 

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