LET and dose rate effect on radiation-induced copolymerization in physical gel

• LET and dose rate effect on polymerization in gel was almost the same as in solution.
• The ratio of the dose rate effect in the gel was higher than that in solution.
• The initiation and termination processes show the difference on the dose rate effect.

N2-saturated 2-propanol solutions containing styrene and maleimide were gelled by the addition of hydroxypropylcellulose and irradiated by proton, He and C-ion beams. The trend in the dose rate and LET effects on the yield and molecular weight distribution of the polymer produced in the gel was almost the same in the solution. On the contrary, the dose rate effect in the gel was higher than that in the solution. This effect was accelerated for irradiations by proton as well as heavier ion with a higher LET value.