Carborane-based multiple-effect coupling protection mechanism assists the design of new high-temperature resistant hybrid resin

Abstract

A high-temperature resistant resin that forms organic–inorganic hybridization in situ through controllable oxidation process of carborane is reported. The precursor of resin that named CEPN is prepared by esterification reaction between 3-(3,4-dicyanophenoxy) benzoic acid (DPBA) and 1,2-bis (4-hydroxyphenyl)-o-carborane (BHCB). The detailed FT-IR and multi-dimensional XPS analysis prove that the light boron element continuously released by carborane during the curing process is oxidized to form the gradient oxygen barrier layer and the local oxygen consumption area. The resulting oxidized areas significantly decreases the likelihood of the cross-linked network being attacked by hot oxygen and slows down the degradation rate of the system. Based on the above mechanism, the resins showed an impressive heat resistance in nitrogen (Td5%, 706.7 °C) and air (Td5%, 666.3 °C) test atmospheres. At the same time, the resin also exhibits excellent thermomechanical stability (Tg, over 550 °C). We believe that the existence of this multi-functional oxidation zone based on the carborane can announces new light on the design concept of high-temperature resistant resin.