Converting PBO fibers into carbon fibers by ultrafast carbonization

We report an ultrafast transformation of poly(p-phenylene-2,6-benzobisoxazole) (PBO) fibers into carbon fibers (CFs) by direct carbonization that eliminates high-cost oxidation in traditional CF conversion. Ultrafast heating and cooling render PBO-derived CFs superlative mechanical properties. ReaxFF atomistic-scale reactive molecular dynamics simulations unveil the PBO to CF conversion mechanism in which ultrafast heating suppresses the O-contained gas release, facilitating all-carbon rings alignment during the carbonization of PBO. These findings provide new guidelines for identifying and evaluating alternative CF precursors and fresh perspectives on smart manufacturing of CFs. (C) 2019 Elsevier Ltd. All rights reserved.