Designing Thermally Resistant Polyimide Oligomers: Insights from Molecular Dynamics Simulations

초록

We perform a systematic computational study for designing high-temperature resistant Oligo-polyimides (Oligo-PIs). Their properties can be significantly enhanced by substituting the diamine component. Oligo-PI Type A- end-capped with 4-Phenylethynyl anhydride (4-PEPA) groups and comprising of 11 repeat units of 1,3-Bis(4-aminophenoxy)benzene (TPE-R) and 10 repeat units of 3,4 '-Biphthalic Anhydride (a-BPDA)) was chosen for modification. We selected 4-PEPA and a-BPDA due to their efficacy in forming thermally stable Oligo-PIs. Here, we developed a molecular modification approach to substitute the Oligo-PI Type A TPE-R segment with various commercially available polyimide (PI) monomers. This method, integrated with high-fidelity molecular dynamics simulations, allowed us to quantitatively predict the glass transition temperature (T g) and identify 27 Oligo-PI candidates demonstrating structural integrity above 823 K, the conventional turbine inlet gas temperature. Posteriori structural analysis revealed important structural attributes such as side group, symmetry and configuration, chain-chain interactions, and molecular symmetry, which are crucial to their high T g. This strategy demonstrates a promising method for the tailored design of high-temperature resistant materials, paving the way for advancements in gas turbine materials.