Quantum chemical calculation of imidization mechanism of polyamic acid

2nd International Conference on New Material and Chemical Industry

材料科学;化学工业

Gu, H.Y.^1 ; Song, L.X.^1 ; Zhang, J.L.^1 ; Wang, L.^1 ; Qi, Z.Y.^1 ; Zhang, T.^1

Key Laboratory of Inorganic Coating Materials CAS, Shanghai Institute of Ceramics, Chinese Academy of Sciences, Shanghai

200050, China^1

关键词: Activation barriers;    Density functional theory methods;    High-activation;    High-energy barriers;    Hydrogen transfer;    Polyamic acids;    Quantum chemical calculations;    Thermal imidization;   

Others  :  https://iopscience.iop.org/article/10.1088/1757-899X/292/1/012116/pdf
DOI  :  10.1088/1757-899X/292/1/012116

学科分类：材料科学（综合）

来源: IOP

【 摘 要 】

In this paper, the imidization mechanism of polyamic acid to prepare polyimide has been studied by the density functional theory (DFT) method. Our results have shown that the imidization would proceed via two different reaction paths. The activation barrier via hydrogen transfer to closer carboxylate oxygen in the COOH is 220.35 kJ/mol while the activation barrier via hydrogen transfer to hydroxyl oxygen in the COOH is 220.70 kJ/mol. Both reaction paths would run in the actual thermal imidization process with closer high activation barriers. The high energy barrier interpreted the fact that additional energy or catalyst is usually needed during imidization. Moreover, the intrinsic imidization mechanism indicated is critical to further improve the imidization process.