Thermal treatment modification method for PBO (Poly-p-phenylene ben-zobisthiazole) fibers

The invention relates to a thermal treatment modification method for PBO (Poly-p-phenylene ben-zobisthiazole) fibers, and belongs to the technical field of macromolecular fiber modification. The thermal treatment modification method for the PBO fibers comprises entering a thermal treatment channel, a preheating section, a thermal treatment section and a cooling section. According to the thermal treatment modification method, the PBO fibers enter the sectional type thermal treatment channel through a tension roller; the preheating section and the cooling section which are additionally arranged in the sectional type thermal treatment channel have an important role in improving the intensity and the modulus of the fibers; as water has a plastification effect, in a preheating process of the preheating section, movement of a molecule chain is facilitated, the mutual action between the specific moisture content and the preheating section is controlled, and the crystallizing degree and the orientation degree of the fibers in the thermal treatment section are improved; finally, due to the cooling section additionally arranged in the sectional type thermal treatment channel, the fibers subjected to thermal treatment can be effectively prevented from being directly exposed in the air, so that high-temperature thermo-oxidative degradation of the fibers in hot air is effectively reduced, and the intensity and the modulus of the treated fibers are greatly improved.