SIMULATION OF TEMPERATURE DISTRIBUTIONS WITHIN MONOMER FILM DURING PHOTOPOLYMERIZATION

Photoinitiated polymerizations are very fast reactions, and consequent ly significant thermal effects are observed during the reactions. Neve rtheless, isothermal conditions are necessary to measure the kinetic c onstants of polymerization. In the simulation of heat transfer reporte d in this paper, it is shown that the use of a thin film of monomer at the bottom of a DSC pan, even in the presence of an intermediate poly ethylene film, is convenient if the reaction rate is not too high. For example, the temperature increase of the film does not exceed 1 degre es C for a reaction half-rime (time to reach 50% conversion) higher th an 10 s when the enthalpy of polymerization is chosen as Delta H-R=115 J g(-1).