Cellular Evolution in PEI: Mapping Bubble Dynamics through Solid-State CO_2 Foaming Processes

Abstract

Future applications of polyetherimide (PEI) extend beyond structural panels and insulation to include vibration-damping layers, impact-resistant aerospace skins, thermal-acoustic insulation, and multifunctional components in satellites and aircraft cabins. By using dynamic mechanical analysis (DMA), a constitutive model for bubble growth under CO_2 saturation is developed, capturing glass transition effects and growth of nanofoam cells. Key properties such as cell growth rate, CO_2 concentration, porosity, and stress are extracted, supporting simulation-driven design of next-generation aerospace structures with enhanced durability, thermal stability, and energy absorption