Heats of Self-Polymerization Reactions

A considerable amount of work on the thermodynamics of polymerization has been carried out by Dainton and his co-workers, and this, together with much other data, has been reviewed. 

For many polymerization reactions the entropy changes have been either measured or calculated, and from these, combined with the measured heats of reaction, the free energies of polymerization can be calculated. From these data it is possible to determine the extent to which polymerization occurs, and the relative influence of the heat and entropy effects on the reaction equilibrium. 

We shall look first at the heats and entropies of seif-polymerization of some Othylene derivatives, and then at similar data for co-polymerization of these derivatives, especially with sulphur dioxide. Finally, we shall mention the influence of strain on the extent of polymerization of heterocyclic compounds. 

The heats of self-polymerization of a number of derivatives are shown in Table 1. They refer to the polymerization of liquid mo- 

CH2==CHC6Ha(013)5, vinyl mesitylene CHa CHCgH Cl, o-chiorostyrene p-chlorostyrene 

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