Effect of Aging Conditions on Anti-bacterial Performance and Mechanical Properties of Polypropylene and Polystyrene Doped with HPQM

Abstract

The effect of service conditions on anti-bacterial performance of polypropylene (PP) and polystyrene (PS) thermoplastics doped with 2–Hydroxypropyl–3–Piperazinyl–Quinoline Carboxylic acid Methacrylate antibacterial agents (HPQM) were studied. HPQM with two different forms, which were HPQM based Neusilin® (HPQM-neu) and HPQM based solution (HPQM-sol), were loaded in the polymers at the loading range of 0-1250 ppm. The antibacterial efficiencies of specimens before and after through service conditions against with Escherichia coli (E.coli) bacteria were indicated by bacteria reduction test. The results suggested that, the optimal HPQM concentrations to reach 99.9% bacteria reduction were 500 and 750 for PP/HPQM-neu and PP/HPQM-sol, respectively, whereas those of PS/HPQM-neu and PS/HPQM-sol were 1250 ppm. After through service conditions at room temperature, the bacteria reduction of PP/HPQM-neu 500 ppm and PS/HPQM-neu 1250 ppm could not reach at 99.9%, but the bacteria reduction of PP/HPQM-sol 750 ppm and PS/HPQM-sol 1250 ppm still reached at 99.9%. When tested at 80oC, the anti-bacteria performance of PP/HPQM-sol 750 ppm and PS/HPQM-sol 1250 ppm became less effectively, not reaching at 99.9%, and tended to drop with increasing water immersion time. The addition of HPQM in both forms into PP and PS did not significantly affect the flexural and Impact properties.