Insight into the formation of conjugated ladder structure of polyacrylonitrile by X-ray photoelectron spectroscopy. (15th August 2022)

• Record Type: Journal Article
• Authors: Shi, Hui; Ouyang, Qin; Wang, Xiaolian; Yang, Yunguo; Song, Tinglu; Hao, Jianwei; Huang, Xianbo
• Is Part Of: Measurement. Volume 200(2022)
• Publication Date: 2022-08-15
• Subjects: Polyacrylonitrile -- Conjugated ladder structure -- Thermal stabilisation -- X-ray photoelectron spectroscopy; Weights and measures -- Periodicals; Measurement -- Periodicals; Measurement; Weights and measures; Periodicals; 530.8
• DOI: 10.1016/j.measurement.2022.111565
• Languages: English
• ISSNs: 0263-2241

Abstract

Highlights: The transition temperature of conjugated ladder structure (TCLS ) of polyacrylonitrile is established. This TCLS during thermal stabilization is proposed to be the efficient temperature of structural evolution. The method based on XPS is proposed for verification of the conjugated ladder structure. Abstract: Understanding the formation of conjugated ladder structure of polyacrylonitrile (PAN) is of great significance to optimize the conditions of thermal stabilisation. Here, X-ray photoelectron spectroscopy (XPS) is applied to observe the structural evolution in order to find the optimal conditions for thermal stabilisation. And a new method of analysing the transition temperature of conjugated ladder structure (TCLS ) is introduced. Thermogravimetric (TG) and differential scanning calorimeter (DSC) analysis confirm the necessity of air atmosphere to the formation of stable structure, and XPS analysis reveals the complete formation of conjugated ladder structure between 200 and 300 °C. In this range, a method of analysing TCLS is established by the considerable increase of conjugated ladder carbon content and asymmetric tail in C1s spectrum. Besides, the optimal conditions for thermal stabilisation are determined, which are a heating rate of 5 °C/min, a temperature of 250 °C (the TCLS ), and a retention time of 60 min, respectively.