Fabrication of polypropylene fibers possessing quaternized ammonium salt based on the combination of CuAAC click chemistry and electrospinning

Abstract

This study provides a straightforward method for preparing fibers of polypropylene possessing quaternary ammonium salt (FPP-QAS) by combining copper (I)-catalyzed azide-alkyne cycloaddition “click” reaction (CuAAC) and electrospinning technique. Initially, chlorinated polypropylene (PP-Cl) is modified to azido-functional polypropylene (PP-N3) in the presence of azidotrimethylsilane (TMS[sbnd]N3) and tetrabutylammonium fluoride (TBAF), whereas alkyne-terminated quaternary ammonium salt (QAS-Alkyne) is synthesized via esterification of 3-dimethylamino-1-propyne with benzyl bromide. Then, FPP-QAS is fabricated by CuAAC reaction between PP-N3 and QAS-Alkyne, and subsequent electrospinning carried out at different feeding rates (FR), applied voltages (AV) and tip-to-collector distances (TCD). After that, the achieved FPP-QAS is analyzed with regard to their wettability, morphological, thermal and antibacterial features by comparing with its not only cast film (CPP-QAS) but also cast film and fibers of chlorinated polypropylene precursor (CPP-Cl and FPP-Cl). The SEM images demonstrate that the formation of microfiber diameter is uniform, cylindrical and smooth without free beads. It is also observed from the results that QAS grafted onto polypropylene backbone not only increase the thermostability and glass transition temperature but also diminish the wettability. The antibacterial activity of the electrospun FPP-QAS sample is found to be higher than that of the electrospun FPP-Cl against both Gram-negative Escherichia coli (E. coli) and Gram-positive Staphylococcus aureus (S. aureus). Thus, FPP-QAS demonstrated in this work can present alternatives to researchers working on the industrial applications of polypropylene.