Antimicrobial properties of poly(propylene) carbonate/Ag nanoparticle-modified tamarind seed polysaccharide with composite films

Completely biodegradable poly(propylene)carbonate-based composite films with 10 wt.% of tamarind seed polysaccharide (TSP) as filler were prepared by solution casting method. In these composite films, using TSP as the reducing agent, silver nanoparticles (AgNPs) were in situ generated using 1 to 5 mM aq. AgNO3 source solutions. The hybrid nanocomposite films were characterized by FTIR spectroscopy, X-ray diffraction, scanning electron microscopy (SEM), polarized optical microscopy (POM), tensile testing, thermogravimetric analysis, and antibacterial studies. From the SEM analysis, it was evident that the particle size of the AgNPs varied between 44 and 86 nm when 1 to 4 mM source solutions were used. But on the other hand, the particle size increased to 406 nm when 5 mM source solution was used indicating agglomeration of the AgNPs. The reinforcement of TSP enhanced the crystallinity of the poly(propylene carbonate) (PPC) matrix. The hybrid nanocomposite films exhibited enhanced tensile and thermal properties when compared with the PPC matrix. Further, the hybrid nanocomposites exhibited excellent antibacterial properties against Escherichia coli (E. coli), Pseudomonas aeruginosa (P. aeruginosa), Bacillus licheniformis (B. licheniformis) and Staphylococcus aureus (S. aureus) bacteria. These hybrid nanocomposites with excellent tensile and antibacterial properties can be potentially used for food packaging applications.