Carboxymethylcellulose acetate butyrate/poly(4-vinyl-N-pentyl pyridinium bromide) blends as antimicrobial coatings

Abstract

Blends of carboxymethyl cellulose acetate butyrate (CMCAB), a cellulose derivative, and poly(4-vinyl-N-pentyl pyridinium bromide) (QPVP-C5), an antimicrobial polymer, were prepared by casting method and characterized by means of Fourier transform infrared vibrational spectroscopy (FTIR), scanning electron microscopy (SEM), thermogravimetric analysis (TGA), differential scanning calorimetry (DSC) and contact angle measurements. Miscibility between CMCAB and QPVP-C5 was evidenced by DSC measurements of blends, which showed a single thermal event of Tg, and SEM images, which revealed homogenous morphology, regardless the blend composition. Moreover, thermal stability of QPVP-C5 was substantially enhanced, when it was mixed with CMCAB. Upon increasing the QPVP-C5 content in the blend the wettability and antimicrobial activity against Gram-positive bacteria Micrococcus luteus increased, indicating the surface enrichment by pyridinium groups. In fact, blends with 70 wt% QPVP-C5 reduced 5 log and 4 log the colony-forming units of Micrococcus luteus and Escherichia coli, respectively.

Keywords

• Coatings
• carboxymethylcellulose acetate
• poly(4-vinyl-N-pentyl pyridini
• antimicrobial properties
• blends