Study On Antibacterial EVA Foamed Materials Containing Zn²⁺, Ag⁺ Or Rare Metals Oxides

With EVA(ethylene vinyl acetate copolymer) as raw materials, zinc-loaded antibacterial powder and silver-loaded zirconium phosphate as antibacterial agents, aluminate, silane and borate as coupling agents, the antibacterial EVA foamed materials were prepared by means of coupling modification, twin-roll mixing and extruding, and compression molding cross-linked foaming. These coupling modification treatments were evaluated by FTIR, hygroscopic property and viscosity. Some instruments, for example, curometer and scanning electron microscopy (SEM), were applied to analyze and observe these EVA samples. Meanwhile, the cross-linked foaming, mechanical and antibacterial properties were mensurated.The antibacterial EVA foamed materials were prepared through development of rare metals oxides (CeO₂,La₂O₃,ZrO₂) doped silver-loaded zirconium phosphate as antibacterial agents. The effects of the mentioned three antibacterial agents on some properties of the EVA samplels were investigated, such as cross-linked foaming properties, thermal decomposition temperature, mechanical properties, antibacterial rates, the water and weathering resistance of persistence antibacterial effects.The results showed that borate coupling agent was of the best modified effects on zinc-loaded antibacterial powder and silver-loaded zirconium phosphate among the mentioned three coupling agents. Compared with the EVA materials without antibacterial agents, the foaming gas pressure of EVA compounded with 2% zinc-loaded antibacterial powder or 1% silver-loaded zirconium phosphate increased during mould foaming process, and the cell size also enlarged, meanwhile, torque value decreased obviously. In a word, these EVA samples exhibit excellent mechanical and antibacterial properties. The presence of rare metals oxides (CeO₂,La₂O₃,ZrO₂) doped silver-loaded zirconium phosphate in the EVA foamed materials resulted in the improving of the thermal decomposition temperature and the mechanical properties significantly. Indeed, the mechanical properties of the foamed EVA antibacterial materials which contain 2.8% CeO₂,La₂O₃,ZrO₂ doped silver-loaded zirconium phosphate, are superior to the normal EVA foamed materials, and antibacterial properties are better than the EVA foamed materials containing 1% silver-loaded zirconium phosphate or 2% zinc-loaded antibacterial powder. Furthermore, the water and weathering resistance of persistence antibacterial effects are excellent.