Synthesis and Characterization of Crosslinked Polyimide Aerogels

Abstract

This thesis details the fabrication and characterization of chemically imidized polyimide aerogels starting from diamines and diacid anhydrides, crosslinked with 1,3,5-benzene tricarbonyl chloride (BTC). Conventional characterization techniques involving Low-Voltage Scanning Electron Microscopy and Fourier-Transform Infrared Spectroscopy were applied to assess their morphology and chemical identity, respectively. Dynamic Mechanical Analysis (DMA) and thermal shrinkage tests were conducted to evaluate the thermal behavior of these materials. Additionally, the electrolyte uptake was tested in mediums of different pH, and Nuclear Magnetic Resonance (NMR) relaxometry studies were performed to gain insight into the hydration mechanism of polyimide aerogels. The focus on thermal and hydration properties is particularly relevant in light of recent advancements, where polyimide aerogels have been proposed as promising alternatives for battery separators, offering improved features of safety and efficiency.