Synthesizing and characterization of novel high‐performance heat‐resistant bismaleimide IPN coatings containing bisphenol A ethoxylate with improved impact resistance, thermal stability, and hydrophobicity

Abstract This study developed novel heat‐resistant bismaleimide IPN coatings (MA‐Bis A coatings) containing a bisphenol A ethoxylate structure with enhanced impact resistance, thermal stability, and hydrophobicity. The coatings employed an interpenetrating polymer network (IPN) formed through cross‐linking between bismaleimide chains and bisphenol A ethoxylate diacrylate (Bis A‐DA), synergistically combining rigid aromatic groups for strength with flexible ether and methylene linkages for impact resistance. A heat‐resistant bismaleimide precursor resin was synthesized and served as the base precursor for MA0, blended with varying amounts of Bis A‐DA to produce MA5, MA15, MA30, and MA50 variants. Fluorine‐ and silicone‐modified MA50 derivatives further enhanced performance. A dual‐cure process involving UV exposure and thermal curing enabled IPN formation. MA50 exhibited a 425% increase in impact resistance, with silicone modifications providing an additional 62% improvement. Silicone‐modified coatings achieved the highest hydrophobicity, with a contact angle of 94° (SI1). Thermal analysis showed T5 values of 391–438°C, T10 values of 416–508°C, and char yields up to 50.4%, with MA50 achieving a Tdi of 433°C. Glass transition temperatures (Tg) ranged from 300°C to 350°C for MA30, MA50, and derivatives. All coatings demonstrated excellent corrosion resistance, adhesion (5B), scratch resistance (6H), and solvent resistance. Highlights Novel heat‐resistant bismaleimide IPN coatings with bisphenol A ethoxylate. Highly improved impact resistance and flexibility. Substantially improved thermal stability. Highly improved hydrophobicity by incorporation with 1% silicon diacrylate. Excellent corrosion resistance, adhesion (5B), and scratch resistance (6H).