Abstract
In the present paper, the relationship between the strength of PIC and the total exposure dosage of gamma-rays was discussed for the mortar specimens containing MMA monomer cured by the irradiation at the dose rate of (1.25, 2.5, 5 and 10)×105 Roentogen/hr. In addition, the effects of the turning irradiation, wrapping and annealing were examined, and the strength of PIC polymerized by the radiation method was compared with that of PIC polymerized by the thermal catalytic initiation method.
The results show that the total radiation dosage for polymerization to obtain the desirable MMA-PIC strength is 4MR at 106R/hr dose rate, 3MR at 5×105R/hr, about 2.5MR at 2.5×105R/hr and 2MR at 1.25×103R/hr. These values change depending upon the ambient temperature in the radiation cave. If the polymerization is carried out under an appropriate condition, the characteristics of PIC, obtained by both the thermal catalytic initiation method and the radiation polymerizing method, are the same. The effect of annealing on PIC strength is negligibly small in the temperature range lower than 100°C. Therefore, it is necessary to make the annealing temperature higher than 100°C. No effect of the turning irradiation was found out.
