Fabrication methodologies for antimicrobial polypropylene surfaces with leachable and nonleachable antimicrobial agents

Abstract Reported herein is the fabrication of antimicrobial polypropylene (PP) surfaces with nonleachable magnesium hydroxide biocides and compares its performance with leachable copper (II) chloride dihydrate. Two methods were used for creating PP‐bearing biocides. One way involves melt‐blending of biocides and PP and subsequent injection molding to create the desired antimicrobial PP surface. Another technique consists of thermal embossing of antimicrobial agents on the PP surface. The biocide‐bearing PP surfaces were evaluated against Escherichia coli ( E. coli ) K‐12 MG1655) for up to 24 h. In the case of injection‐molded PP system, leachable CuCl 2 ·2H 2 O showed a 5.87 ± 0.01 log reduction after 24 h, but only 0.47 ± 0.03 log reduction for PP bearing nonleachable Mg(OH) 2 . On the contrary, thermally embossed PP with CuCl 2 ·2H 2 O and Mg(OH) 2 showed 2.28 ± 0.03 and 3.78 ± 0.03 log reductions, respectively, after 24 h. The nonleachable Mg(OH) 2 imparted antimicrobial properties only to the PP surface prepared via thermal embossing. In contrast, owning to the leachable copper ions, leachable CuCl 2 ·2H 2 O biocides imparted PP surfaces antimicrobial irrespective of the molding or surface embossing approach. This approach provides an advantage for nonleachable PP‐based antimicrobial surfaces in overcoming the toxicity concern associated with plastics bearing leachable biocides.