Development of PP/EPDM thermoplastic elastomer by doped with 2-hydroxypropyl- 3-piperazinyl-quinoline carboxylic acid methacrylate based neusilin® for sanitary applications

Abstract

The effect of the addition of 2-Hydroxypropyl-3-Piperazinyl-Quinoline carboxylic acid Methacrylate (HPQM) in Neusilin® into thermoplastic vulcanizates (TPV) Polypropylene/ethylene propylene diene monomer (PP/EPDM) type on the mechanical and antibacterial properties were studied. Ethylene propylene diene monomer compounds were mixed with Zinc dimethacrylate (ZDMA), Dicumyl peroxide (DCP), and paraffin oil by a two-roll mill machine. Polypropylene and HPQM in Neusilin® were extruded by varies HPQM content 0, 1250, 2500, 3750 and 5000 ppm. Polypropylene added antibacterial agent and EPDM compounds were mixed by twin-screw extruded weight ratios of 100:0, 75:25, 50:50, and 25:75 w/w with varied screw speeds of 60, 80, and 100 r/min. Polypropylene/Ethylene propylene diene monomer compounds were produced by compression moulding to form specimens. The mechanical properties were tested by tensile test and hardness test. It was found that screw speed did not affect the mechanical properties. Disk diffusion test and plate count agar (PCA) method were used for antibacterial properties. For both methods, the specimens contained an antibacterial agent against Escherichia coli ( E. coli ATCC 25922) and Staphylococcus aureus ( S. aureus ATCC 25923). The result of the disk diffusion test suggests that the more HPQM in Neusilin® content, the more the inhibition radius of only E. Coli bacteria. Plate count agar method proceeded by varying the contact time at 0, 1, 2, 3 and 4 h. Viable cell counts of E. coli decreased significantly at HPQM content 2500 ppm, while the viable cell count of S. aureus remained unchanged at 3750 ppm. Moreover, the rubber ingredients in EPDM, which are DCP and ZDMA, affect the release of antibacterial agents by hydrophobic characteristics and compatible conditions.