熔融纺制的沥青基炭纤维

MELT SPINNING PITCH-BASED CARBON FIBERS

虽然沥青基炭纤维可以熔融纺制,但中间相沥青的流动性使得它极难处置。同许多液体一样,中间相沥青也可以是非牛顿型的。但其粘度对温度的敏感性要比大多数熔融纺丝物料的感性高得多。在本研究中,应用能量平衡和力平衡来论证工艺参数和原料性质对中间相可纺性的影响。研究结果表明:在熔融纺丝期间,温度与中间相粘度的相关性会产生丝的应力,这种应力接近丝的抗拉强度极限。因此,在沥青基炭纤维形成过程中,控制温度和传热速率是极为关键的。

Although pitch-based carbon fibers can be melt spun, the flow characteristics of mesophase pitch make it extremely difficult to process. Mesophase pitch, like many fluids, can be non-Newtonian, but its viscosity is considerably more temperature sensitive then most melt-spun materials. In the present study, energy and force balances are applied to demonstrate the influence of process variables and material properties on the spinability of mesophase. The results indicate that the extreme temperature dependence of the viscosity of mesophase can create filament stresses during melt spinning that are near the ultimate tensile strength of the filament.Therefore,The control of both temperature and heat-transfer rate is extremely critical during the formation of pitch-based carbon fibers.