Study On Antifungal And Antibacterial Performance Of The EVA Foamed Materials Containing DCOIT, Zinc-loaded, Silver-loaded Antimicrobial

With EVA (ethylene-vinyl acetate copolymer) as raw materials and DCOIT (4,5-dichloro-2-n-octyl-3-isothiazolone), zinc-loaded antimicrobial and silver-loaded zirconium phosphate as antimicrobial agents, the antimicrobial EVA foamed materials were prepared. The surface modification of zinc-loaded antimicrobial and silver-loaded zirconium phosphate was conducted by using borate as coupling agent, and the treatments were evaluated. Measurement of paper bacterial(fungal) inhibition zone, spore germination test, nature mould collection and toxicity test was carried out on the antimicrobial agents and the influence of bacterium cell was observed by the transmission electron microscope (TEM). Meanwhile, the mechanical, antifungal and antibacterial properties of the antimicrobial EVA foamed materials were mensurated and the water and weather resistance of persistent antimicrobial effects were analyzed. In addition, the antimicrobial EVA foamed materials were prepared through development of CeO₂ and La₂O₃ doped silver-loaded zirconium phosphate as antimicrobial agents, and the influence on the antibacterial properties of the EVA samples produced by the mentioned antimicrobial agents was investigated.The results indicated that DCOIT and zinc-loaded antimicrobial together with their EVA foamed materials had conspicuous inhibitory effect on Staphylococcus aureus, Escherichia coli, Penicillium funiculosum, Chaetomium globosum, Aspergillus niger, Aureobasidium pullulans and many other kinds of mould existing in nature; Silver-loaded zirconium phosphate and its EVA products were of powerful effect against bacterium, but the inhibitory effect on mould was relatively weak; DCOIT and Silver-loaded zirconium phosphate made the cell appearance of bacterium change conspicuously, the cell walls were disruptive and the cells were cavitate; The presence of La₂O₃ and CeO₂ doped silver-loaded zirconium phosphate in the EVA foamed materials resulted in the significant improvement of the antibacterial properties, and the persistent antibacterial effects of the samples were excellent; The mechanical properties of the antimicrobial EVA foamed materials which contained antimicrobial powder that was suface-modified by borate coupling agent were superior to the normal EVA foamed materials, and the addition of CeO₂,La₂O₃ doped silver-loaded zirconium phosphate showed the similar results; The oral LD50 of zinc-loaded antimicrobial and Silver-loaded zirconium phosphate in male and female mice was >5000 mg/kg, so the antimicrobials were of nontoxicity.