Development of novel hybrid materials from polylactic acid and nano-silver coated carbon black with distinct antimicrobial and electrical properties

This work aims to prepare nanosilver coated carbon black via benzoxazine oxidation as a filler for polylactic acid (PLA) to produce novel hybrid materials with improved electrical and antimicrobial properties. Nanosilver coated carbon black exhibited antimicrobial activity against S.aureus, B.subtilis, M.luteus, E.coli, P.aeruginosa and C.albicans. It was found that the nanosilver coated carbon black (10CB-Ag) was the most effective filler since it showed largest inhibition zones. Thermogravimetric analysis (TGA) showed that the silver content in 10CB-Ag was 5.68% by weight. The hybrid materials of PLA with uncoated carbon black and nanosilver coated carbon black fillers were prepared by injection molding. The optimal composition of the prepared hybrid materials was found to be 15 phr of nanosilver coated carbon black in PLA (15AgCB-PLA). This material showed quite good properties, e.g. tensile strength of 50 MPa, % elongation at break of 1.68 and electrical conductivity of 2.78 × 10^?9 S?m^?1. Moreover, it exhibited the S. aureus inhibition of about 99%. This work revealed the possibility of using this material for anti-electrostatic and antimicrobial applications.