Unique surface modified aramid fibers with improved flame retardancy, tensile properties, surface activity and UV-resistance through in situ formation of hyperbranched polysiloxane–Ce0.8Ca0.2O1.8 hybrids

Abstract

It is a great challenge to endow aramid fibers (KFs) with improved flame retardancy and high mechanical properties while simultaneously overcoming their poor surface activity and UV-resistance; however, no such work has been reported to date. Herein, a new type of surface modified KF with hyperbranched polysiloxane (HSi)–Ce_0.8Ca_0.2O_1.8 hybridized coating, HSi–Ce_0.8Ca_0.2O_1.8@KF, was prepared through an in situ methodology. The influence of the loading of HSi–Ce_0.8Ca_0.2O_1.8 on the structure and integrated performance of HSi–Ce_0.8Ca_0.2O_1.8@KFs was intensively studied and compared with KF and coated fibers with HSi or Ce_0.8Ca_0.2O_1.8. Results show that the HSi–Ce_0.8Ca_0.2O_1.8 hybrid has a greater ability in improving flame retardancy, UV resistance and surface activity of KF; in addition, the hybrid exhibits a synergistic effect with HSi and Ce_0.8Ca_0.2O_1.8. The peak heat release rate of HSi–Ce_0.8Ca_0.2O_1.8@KF decreases by 47.7%. After 168 h of-UV irradiation, the retentions of the tensile strength of HSi–Ce_0.8Ca_0.2O_1.8@KFs reach 91.9–97.4%, while the initial decomposition temperature of HSi–Ce_0.8Ca_0.2O_1.8@KF is about 96 °C higher than that of KF. The origin behind the synergistic effect with HSi and Ce_0.8Ca_0.2O_1.8 was also intensively studied.