Synthesis of fluorinated polypropylene using CuAAC click chemistry

Synthesis of fluorine containing polypropylene (PP-F) from chlorinated polypropylene (PP-Cl) via Cu(I) catalyzed Huisgen type 1,3-dipolar cycloaddition (CuAAC) and its water repellency properties are demonstrated. Initially, clickable azido-functional polypropylene (PP-N-3) and alkyne-functionalized fluorine compound (F-Al) are independently prepared by nucleophilic substitution of PP-Cl with azidotrimethylsilane-tetrabutylammonium fluoride and esterification reactions of 2,2,3,3,4,4,5,5-octafluoro-1-pentanol with 4-pentyonic acid. The CuAAC reaction between PP-N-3 and F-Al leads to corresponding PP-F under mild conditions. The chemical structures and surface properties of desired PP-F are characterized by Fourier transform infrared, H-1-NMR, differential scanning calorimetry, scanning electron microscopy, atomic force microscope, and contact angle analyses. Based on water contact angle (WCA) measurement, it is found that both PP-Cl and PP-N-3 films have shown similar hydrophobicity, whereas the WCA of PP-F is surprisingly decreased due to the presence of ester and triazole groups coming from F-Al compound and the clicked product. This facile modification procedure could be utilized in order to alter the wetting or thermal properties of the commercial polymers for potential applications. (c) 2018 Wiley Periodicals, Inc.