Abstract: | The polymerization of styrene (St) in benzene solution in the presence of 1,3-dioxane (DON), 1,3-dioxepane (DOP), trioxane (TRON), or tetraoxane (TEON) by means of photoirradiation of the system at 40°C has been studied kinetically from the standpoint of photosensitized polymerization. The rate of photosensitized polymerization Rp increased in the order: DOP < DON < TRON < TEON, as shown by the rate constant of decomposition of cyclic acetals, and then could be expressed by Rp = kmonocyclic acetal]0.5St]1.0. The polymerization was confirmed to proceed via a radical mechanism. |