Synthesis of high temperature resistant BADCy/PES/BMI resin adhesive by solvent-free method and its performance characterization

A series of high temperature resistant adhesives were synthesis from 2,2’-Bis-(4-cyanatophenyl) (BADCy), polyethersulfone (PES) and N, N’-4,4’-diphenylmethane bismaleimide (BMI) by solvent-free method. The effect of BMI content on the curing behavior, thermal, mechanical, fracture morphology, adhesive and thermal aging properties were studied. With the addition of BMI, the curing activation energy of resin increases from 67.44 kJ/mol of BMI-0 to 69.22 kJ/mol of BMI-30. The reason is mainly due to the higher activation energy of BMI self-polymerization. The BADCy/PES/BMI resin has a wider processing window (BMI-20 has the lowest viscosity in the range of 96°–182 °C), and the processing window becomes wider as the BMI content increases. More interestingly, as BMI content increases, resins toughness decreases and lap shear strength at room temperature decreases (from 31.4 MPa of BMI-0 to 20.0 MPa of BMI-30), but the high temperature performance increases as BMI content increases (temperature for 5% weight loss under N2 atmosphere of BADCy/PES/BMI increase from 404 °C of BMI-0 to 413 °C of BMI-30).