Abstract: A series of polylysine/nylon-6（ε-PL/PA6）composites with varying ε-PL content were prepared using a solution blending method with nylon-6 (PA6) and polylysine (ε-PL) as raw materials. The structure and properties of the ε-PL/PA6 composites were systematically studied using scanning electron microscopy, thermogravimetric analysis, differential scanning calorimetry, and X-ray diffraction. The results showed that when the mass fraction of ε-PL was 15%, ε-PL was most uniformly dispersed in PA6. The ε-PL/PA6 composite did not affect the crystalline form of PA6, but it increased the crystallization temperature and decreased the melting point. In the compression-molded ε-PL/PA6 composite samples, ε-PL could be continuously and slowly released in water, and the slow-release process followed the logistic model. The ε-PL/PA6 composites with an ε-PL mass fraction of 10%―20% exhibited excellent dissolution antibacterial properties and surface antibacterial properties, with surface antibacterial rates against Escherichia coli and Staphylococcus aureus both exceeding 99.99%. These composites are novel antibacterial composite polymer materials that possess both surface antibacterial and slow-release antibacterial functions.

Key words: nylon-6, polylysine, sustained release, antibacterial, composites material