- 作者: 葉錫溶; 陳燦然
- 作者服務機構: Contribution from the Institute of Nuclear Science, National Tsing Hua University
- 中文摘要:
Thin films of fractionated polyvinyl chloride were irradiated both in the air and in vacuum with electron beam of different dose rates generated by Van de Graaff generator. The dose rates used in this study ranged from 3.97×10.. rads/sec. The temperature of irradiation was kept below 30℃ to eliminate the heat effect due to electron beam irradiation. The molecular weights of the irradiated polymer were estimated by measuring the viscosity of irradiated polyvinyl solution chloride in cyclohexanone. The estimation was carried out immediately after irradiation to avoid the post irradiation effect.
When the polyvinyl chloride was irradiated in the air with the dose rate below 2.27×10.. rads/sec, the molecular weights of irradiated polyvinyl chloride decreased gradually. Beyond the total dose of 3.4×10.. rads, however, the molecular weights of irradiated polyvinyl chloride began to increase. Nevertheless, when the dose rate higher than 2.87×10.. rads/sec was applied, the molecular weights of the irradiated polyvinyl chloride increased as soon as the polymer was subjected to irradiation. In all case studied the molecular weights of polyvinyl chloride increased rapidly beyond the total dosage of 5×10.. rads, and the polymer became insoluble when the total dosage reached 7×10.. rads. More clear cut trend was observed when the polyvinyl chloride was irradiated in vacuum. - 英文摘要: --
- 中文關鍵字: --
- 英文關鍵字: --