The Polymer Society of Korea

Abstract

Although epoxy resins exhibit excellent mechanical strength, adhesion, and thermal stability, their inherent flammability restricts use at elevated temperature. Here, we mitigate this limitation by embedding silica-microencapsulated intumescent flame-retardant (MCIFR) particles in a diglycidyl ether of bisphenol A (DGEBA) and diaminodiphenylmethane (DDM) epoxy matrix. Pentaerythritol (PER) and ammonium polyphosphate (APP), key intumescent components, were individually microencapsulated though a TEOS sol-gel route and subsequently functionalized with APTES to enhance interfacial compatibility. During combustion, the MCIFR generated an expanded silica-reinforced char that impedes heat and oxygen transfer, thereby improving flame retardancy. The hybrid composites were evaluated for the structure, thermal properties, and flame retardancy using various analytical methods.