Effects of solution and solid forms of 2-hydroxypropyl-3-piperazinyl-quinoline carboxylic acid methacrylate on antibacterial, physical and mechanical properties of polypropylene sheeting

Two forms of an inorganic antibacterial agent, 2-hydroxypropyl-3-piperazinyl-quinoline carboxylic acid methacrylate (HPQM), were added into polypropylene sheet. The polypropylene sheet antibacterial, physical, and mechanical performance was assessed before and after exposure to ultraviolet light at different ultraviolet aging times. Water-based HPQM (HPQM-solution) and HPQM in magnesium aluminometasilicate or Neusilin (HPQM-Neusilin) were supplied in liquid and solid powder forms, respectively. Halo test and dynamic shake flask method, together with plate count agar technique, were used for quantitative antibacterial performance analysis; the results were reported as radius of inhibition zone and bacterial reduction. The results suggested that the HPQM-Neusilin samples exhibited more effective antibacterial performance than the HPQM-Solution samples. Adding HPQM-Neusilin considerably changed the polypropylene sheet lightness ( L*). Introducing HPQM-solution into polypropylene did not change the polypropylene sheet physical and mechanical properties. Both HPQM forms showed very effective antibacterial performance against E. coli, but not against B. cereus. The minimum HPQM concentration to achieve 99.9% bacterial reduction for HPQM-solution and HPQM-Neusilin samples were 750 and 500 ppm, respectively. The antibacterial efficacies of polypropylene supplemented with HPQM disappeared after 24-h ultraviolet aging.