Developing thermally resistant polydopamine@nano turbostratic BN@CeO_2 double core-shell ultraviolet absorber with low light-catalysis activity and its grafted high performance aramid fibers

摘要

Constructing novel surface structure to overcome two bottlenecks (low surface activity and poor resistance to UV) of aramid fiber (KF) is a meaningful topic. Herein, a new hybridized UV absorber (PDA@tBN@CeO2) with strong UV absorption, low catalytic activity and high heat resistance was synthesized by forming nano turbostratic boron nitride (tBN) and polydopamine (PDA) shells on CeO2 core, successively. The double shell-core structure not only significantly reduces the photocatalytic activity of CeO2, but also obviously improves the UV-blocking effect of CeO2 and provides active groups for chemical grafting with KF. On this basis, three modified KFs (T-KF1, T-KF2, T-KF3) were fabricated by constructing unique surface structure with different loading of PDA@tBN@CeO2 through chemical bonds, guaranteeing the good interface between KF and PDA@tBN@CeO2. The effects of PDA@tBN@CeO2 concentration on structure and overall performances (surface activity, UV resistance, thermal and mechanical properties) of T-KF fibers were investigated. All T-KFs have greatly improved surface activity and UV-resistance, the improvement degree is dependent on the loading of PDA@tBN@CeO2. For T-KF2 with 1 wt% of PDA@tBN@CeO2, its initial decomposition temperature and the value after 168 h-UV irradiation are 49 degrees C and 90 degrees C higher than those of original KF, respectively; moreover, tensile strength and energy to break of T-KF2 are severally 1.14 and 1.21 times of those of original KF, the simultaneously improved degrees are the best values among modified KFs reported so far. In addition, T-KFs show outstanding retentions of tensile performances after 168 h UV irradiation, especially, the retention of energy to break of T-KF2 is 1.62 times of that of KF. The excellent integrated performances of T-KF are proved to be attributed to the unique structure of PDA@tBN@CeO2 as well as the interaction between PDA@tBN@CeO2 and KF. (C) 2018 Elsevier B.V. All rights reserved.