紫外光照射对PBO纤维结构与性能的影响

Effect of ultraviolet irradiation on structure and properties of PBO fiber

采用UVA,UVB,UVC 3种波段紫外光分别对聚对苯撑苯并双噁唑(PBO)纤维进行照射,研究了不同照射时间下PBO纤维的结构与性能。结果表明:PBO纤维经不同波段紫外光照射6 d时,UVA照射后纤维噁唑环稳定性降低,断裂强力下降率为5.42%,UVB照射后纤维噁唑环开始发生开环,断裂强力下降率为13.46%,UVC照射后纤维噁唑环已打开,断裂强力下降率为18.96%;经UVA,UVB,UVC照射13 d后,PBO纤维断裂强力下降率分别为19.36%,38.65%,53.13%,PBO纤维大分子均遭到破坏;UVC照射后PBO纤维起始分解温度下降至51℃,UVA,UVB照射后PBO纤维基本能保持自身良好的热学性能;PBO纤维最敏感的紫外光是UVC,其次是UVB,最后是UVA。

Poly（ p-phenylene-benzobisoxazole）（ PBO） fiber was exposed to ultraviolet irradiation of different bands,i. e. UVA,UVB and UVC. The structure and properties of PBO fiber were studied after ultraviolet irradiation for different periods of time. The results showed that UVA made the stability of oxazole ring depressed and the breaking strength decrease by 5. 42%,UVB made the oxazole ring start to open and the breaking strength decrease by 13. 46%,UVC made the oxazole ring open and the breaking strength decrease by 18. 96% when the PBO fiber was exposed to ultraviolet irradiation for 6 d; UVA,UVB and UVC irradiation for 13 d made the breaking strength decrease by 19. 36%,38. 65% and 53. 13%,respectively,and the macromolecules of PBO fiber damaged; UVC made the initial decomposition temperature of PBO fiber decrease to 51 ℃,and UVA and UVB made the thermal properties of PBO fiber keep fairly good; and PBO fiber was sensitive to UVC,UVB and UVA from the most to the least.