Radical Polymerization in the Solid State

Many authors have studied radical polymerization in the solid state by using the ESR technique. An advantage of studying polymerizations in the solid state is the long life time of free radicals leading to much higher concentrations than that in the liquid state. As an example, the benzoyl peroxide (BPO)-initiated polymerization of methyl methacrylate (MMA) in frozen aromatic solvents with irradiation of light is shown in Fig. 7.4 [4]. 

Kamachi et al. [5] calculated the conformation energy of the propagating radical of MMA and found that two stable conformations with different dihedral angles between the (Ca )—Hp bond and the p-orbital were possible. There are two possible 

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