Pbo Fiber, Heat Resistance And Uv Characteristics

High performance PBO (poly (p-phenylene-2, 6-benzobisoxazole)) fiber, because of its excellent mechanics, heat resistance function and fire-retardant property, has been used in many fields include military and public. It is called super fiber of 21 century.This kind of new fiber is placed in the stage of beginning in our country and there is not enough information of its properties. An integrated and detailed research about PBO single fiber treated with heat is done and gets some useful datum for reliable composite design. These information and datum can offer necessary support for the design of PBO fiber composites in the future.Based of Weibull / weakest link model, the statistic average strength and its distribution of four different length PBO single fibers which were treated with heat and ultraviolet radiation were researched. The tensile force of every single fiber was measured and the exactness of Weibull distribution was checked up by using Kolmogorov examination. The results point out the complexion that the statistical strength changed with fiber length. From the experiment, the equation to forecast the strength of PBO fiber is deduced. The results also indicate the statistical strength of fibers treated with heat decrease by length and critical length is 3~4cm. when fiber length exceed critical length, the influence of fiber length to statistical strength indistinct. The paper indicates the relation of treatment temperature and strength distribution.Subsequently, the 3cm PBO fibers are treated with 350℃ and ultraviolet radiation different hours. The results show the PBO fiber depredates with treatment hours and temperature. When treatment time is 6h, 10h, 14h, 19h and 25h under 350℃,the strength retention is respectively 90.89%,85.49%,78.58%,69.81% and 60.71%;When UV radiation time is 1h, 6. 5h, 11h and 18h, the strength retention is respectively 98.65%,96.46%,90.39% and 86.17%.The results show PBO fiber hasperformance of excellent heat-resistant and general UV-resistant..The surface of treated fibers can be observed by using SEM. The surfaces are no more lubricous and present vice such as groove and disfigurement because of oxidation. The surfaces also show micro-fiber crazing and peeling out. These phenomena are main reason why the statistic average strength and its distribution change.