Effect of different aromatic amines on the crosslinking behavior and thermal properties of phthalonitrile oligomer containing biphenyl ethernitrile

Abstract

Abstract To find a proper amine to promote the processability of phthalonitrile‐based composites, three different aromatic amines: 4‐aminophenoxyphthalonitrile (APN), 2,6‐bis (4‐diaminobenzoxy) benzonitrile (BDB) and 4,4′‐diaminediphenyl sulfone (DDS) were used as curing agents to investigate the crosslinking behavior and thermal decomposition behavior of phthalonitrile oligomer containing biphenyl ethernitrile (2PEN‐BPh). Differential scanning calorimeter (DSC) and dynamic rheological analysis were employed to study the curing reaction behavior of the phthalonitrile/amine blends and prepolymers. The studies revealed that BDB was the preferred curing agent and the preferred concentration of BDB was 3 wt %. The thermal properties of the 2PEN‐BPh polymers were monitored by TGA, and the results indicated that all the completely cured 2PEN‐BPh polymers maintained good structure integrity upon heating to elevated temperatures and these polymers could thermal stabilize up to over 550°C in both air and nitrogen atmospheres. Dynamic mechanical analysis (DMA) showed the glass transition temperature ( T g ) exceeded 450°C when the 2PEN‐BPh polymer post cured at 375°C for 8 h. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011