Direct preparation of carbon foam by pyrolysis of cyanate ester resin at ambient pressure

• A carbon foam with an average pore size of 200 μm can be directly prepared by pyrolysis of bisphenol A cyanate ester (CE) resin at ambient pressure.
• The CE resin undergoes the main thermal decomposition and produces rich pores in the temperature range of 400–600 ̊C.
• The carbon foam possesses a relatively high compressive strength, which is due to its well-developed pore structures without obvious cracks or voids.

In this work, a simple and efficient method to fabricate carbon foams from bisphenol A cyanate ester (CE) was developed. Pyrolysis behavior of the CE resin was investigated by thermogravimetric analysis (TGA), Fourier transform infrared spectroscopy (FTIR) and scanning electron microscopy (SEM). Results show that the carbon foam with an average pore size of 200 μm can be directly prepared by pyrolysis of the resin at ambient pressure. The resin has self-foaming characteristics at high temperatures, and its development of pore structures is mainly in the temperature range of 400–600 ̊C. The resultant carbon foam possesses a compressive strength of 3.15 MPa at a bulk density of 0.26 g/cm3, which is due to its well-developed pore structures without obvious cracks or voids.