| Abstract: | The radiation-induced postpolymerization of trioxane with 1,3-dioxolane has been investigated. Trioxane and 1,3-dioxolane were carefully purified in a rigorously dry, high-vacuum system. In the present study it was found that trioxane can be easily copolymerized with 1,3-dioxolane to give a copolymer having high molecular weight and excellent thermal stability. Typically, the isothermal weight loss after heating for 60 minutes under nitrogen at 222°C was 3.5% for a copolymer of trioxane and 1.0 wt-%1,3-dioxolane preirradiated with a dose of 1.0 × 105 Rad. The thermal stability of the copolymer was scarcely affected by the polymerization temperature and time, although it decreased slightly with increasing preirradiation dose. The dependences of the yield and inherent viscosity of the polymer on the preirradiation dosage, polymerization temperature and time were quite similar to those found for the homopolymerization of trioxane. The results were analyzed by using the kinetic scheme previously reported, and it was found that no chain transfer reaction occurs in this system. These results are discussed in comparison with those of homopolymerization reported previously. |
