臭氧气氛中聚丙烯腈纤维预氧化过程中的热行为

Thermal behavior of polyacrylonitrile fiber during preoxidization in ozone atmosphere

通过测量聚丙烯腈(PAN)纤维在空气和臭氧气氛下预氧化过程中的热应力行为,比较空气和臭氧气氛中预氧化所得纤维的物化性质。结果表明:PAN纤维在臭氧气氛中进行预氧化时,纤维的物理收缩应力和化学收缩应力比空气中的小,应力松弛严重;纤维在臭氧气氛中的敏感温度均比空气中的高,化学反应推迟;相同的升温速率下,臭氧气氛中纤维发生化学反应的时间较空气中的少,臭氧中纤维的化学反应速率较空气中的快;两种气氛中纤维的体积密度相差很小,臭氧中纤维皮芯结构状况较严重。

The thermal stress behavior of polyacrylonitrile fiber was measured during preoxidization in air and ozone atmosphere. The physico-chemical properties of the preoxidized fibers were compared in the atmosphere of air and ozone. The results showed that the PAN fiber preoxidized in ozone atmosphere exhibited the physical and chemical shrinking stress lower than the fiber preoxidized in air atmosphere and appeared more serious stress relaxation; the fiber had higher sensitive temperature in ozone atmosphere than in air atmosphere and the chemical reaction was postponed; the chemical reaction of the fiber proceeded more quickly and took less time in ozone atmosphere than in air atmosphere at the same heating rate ; the fiber had little difference in volume density in these two atmosphere, but the formation of sheath-core structure was more serious in ozone atmosphere.