Research On Novel Polymeric Antibacterial Agents And Antibacterial Materials

In this paper, three kinds of antibacterial polymers were prepared. They are antibacterial plastic, resin and fiber. The preparation conditions were optimized. And antibacterial tests were carried out.The ion-exchanged zeolites were used as antimicrobials in plastics, and were prepared by solution exchange. Two kinds of inorganic antibacterial agents, single-ion exchanged zeolite (silver zeolite, zinc zeolite) and bi-ion exchanged zeolite (silver-zinc zeolite) were prepared. The preparing conditions were investigated. The antibacterial test shows that the bi-ion-exchanged zeolite has the best antibacterial effect. And for the single-ion exchanged zeolite, the antibacterial effect of silver zeolite is better. The prepared antibacterial agent was blended with PE or PP, and antibacterial assessment shows that the polymer composite exhibits satisfying antibacterial effect.The insoluble crosslinked polystyrenes (PS) grafted with different quaternary ammonium groups were synthesized as antibacterial agents. Their antibacterial activities against Staphylococcus aureus (S. aureus) were investigated by a colony count method. It was found that when the concentration of the insoluble antibacterial agent is low, the antibacterial activity is different from the typical soluble antibacterial agent. The antibacterial activity is bacteriostatic rather than bactericidal. A model for explanation of the antibacterial activity of the insoluble ammonium salt was set up. We believe that the structure of the crosslinked polystyrene is the key point to the antibacterial activity. The result of antibacterial activity of insoluble ammonium salts in low concentration shows that the removal of the bacterial in the suspension is in the way of capturing the bacterial in a living mode. The adsorption process plays an important role in the antibacterial behavior. Especially the adsorption of the dead cells may greatly affect the antibacterial activity of the insoluble ammonium salt.We also investigated the preparation of antibacterial fiber. The Cu2+ was introduced into the viscose fiber by making use of the complexion reaction of the hydroxyl group on the fiber. The preparing conditions and antibacterial test were investigated.There are three notable novel points in this paper: (1) we applied the improved method of Optical Density (O.D.) measurement to assess the antibacterial ability of the ion-exchanged zeolites. This method is much easier and faster than the old MIC method. What's more, it is appropriate for the comparison of a series of antibacterial agents; (2) we set up a model for the antibacterial activity of the insoluble polymeric ammonium salts. This new model can explain and simulate the experiment data quite well. Accordingly, a possible mechanism was proposed; (3) we prepared the antibacterial fiber by directly complex the Cu2+ on the viscose fiber.In the research work of this paper, we have tried many methods for study of antibacterial polymers. We have engaged inorganic antibacterial agents, such as silver and zinc ion-exchanged zeolite, and also organic ones, such as quaternary salts; we also used different supports for antimicrobials, such as zeolite, macroporous resin, and viscose fiber; by using blending, chemical bonding, complex bonding, we introduced the antibacterial agents into the polymer materials; finally, we investigated the antibacterial activity of different agents and materials by carrying different antibacterial tests. We set up the model for antibacterial activity, and tried to explain the mechanisms of the antibacterial behaviors. The research work provides valuable information for synthesizing more secure and efficient antimicrobials and antibacterial materials in the near future.