Dissolution of Aramid by Ionization of Byproduct HCl Promoted by Acetate

Poor solubility of high‐performance polymer has always been a leading bottleneck for its application. Para‐aramid fiber as a typical high‐performance fiber owns significant hydrogen‐bond interaction and chloride salts are generally needed to provide Cl − ions as hydrogen‐bond acceptors for its dissolution. In this paper, Poly‐(benzimidazole‐terephthalamide) (PABI) which complexed with by‐product HCl (PABI‐HCl) during polymerization was fabricated and by‐product HCl was regarded as potential Cl − ions donor. CH 3 COONa as cosolvent was added in DMAc to dissolve PABI‐HCl. It was confirmed that solubility of PABI‐HCl in DMAc could be improved significantly in existence of CH 3 COONa. The finding was characterized by conductivity measurement, UV‐Vis spectra, Atomic Absorbance Spectra and Thermogravimetric analysis etc. By‐product HCl as a strong acid was converted into CH 3 COOH due to existence of CH 3 COO − in solution. Then it would release Cl − ions and they could interact with secondary amide of aramid to disrupt interaction among macromolecules. Therefore, aramid was dissolved successfully by utilizing by‐product HCl and no external Cl − ions donor was needed.