Effects of Combined Gamma Radiation and Thermal Exposure on Some Mechanical Properties of Three Polyaromatic Yarns
1967
Opt, Preston C. | Ross, Jack H.
Three experimental polymeric yarns, a polyimide, an aromatic polyamide, and a polybenzimidazole, were exposed to various gamma dosages up to 1.4 × 10⁹ ergs/g carbon and exposure times up to 18.2 hr. Specimens ere exposed to the gamma radiation alone and also in combination with elevated temperatures. Temperatures of 400°, 600°, and 800°F were used in conjunction with the gamma radiation. All speci mens were evaluated for mechanical properties, i.e., tenacity, elongation, and work-to- rupture. Each polymeric yarn had higher strength, greater elongation, and better energy absorbing capability after thermal-gamma exposure. Exposure at 600°F and all radia tion dosages gave the best results for the polybenzimidazole (PBI) yarn, while exposure at 400°F and radiation dosages of 1.9 × 10⁸ and 7.3 × 10⁸ ergs/g carbon gave the best results for the polyimide and aromatic polyamide yarns. It can be concluded that the thermal stability of these yarns can be improved by thermal gamma treatment.
显示更多 [+] 显示较少 [-]