One acetylenic monomer (APCB) containing carborane with extremely thermal and thermo-oxidative stability was synthesized and used as the thermal copolymerization component with acetylene-terminated imide monomer (m-EFDA) to improve the thermal and thermo-oxidative stability of the polyimide materials. The curing behavior of the blends of imide monomer and APCB was investigated by FT-IR and DSC. Rheometer study showed that the addition of APCB into m-EFDA reduced the minimum complex viscosity of m-EFDA and lowered the temperature of the minimum viscosity. The thermal and thermo-oxidative stability of the thermoset derived from m-EFDA was greatly improved by the addition of APCB based on thermogravimetric analysis. m-EFDA with an addition of APCB at a loading level of 50 wt% exhibited a high char yield of 91.5% at 1000 degrees C in air and a weight retention of 95.6% was obtained after aging in air at 400 and 500 degrees C for 5 h, respectively. (C) 2017 Elsevier Ltd. All rights reserved.