Research And Application Of Chitosan-Based Complex Antimicrobial Agent

In this paper, the preparation, characterization and application of a new broad-spectral complex antimicrobial agent: Ag- carboxylmethyl chitosan-thiabendazole (Ag-CMCTS-TBZ), as well as its monocomponent-based agents, were researched. The major conclusions are:1. It was identified that carboxylmethyl chitosan (CMCTS) shows stronger antimicrobial activities than the uncarboxylmethyled chitosan (CTS), and CMCTS prepared by high molecular weight (305,000) of CTS has stronger antimicrobial activities to the chosen microbial representatives S. aureus, A. niger and M. sp., except E. coli that is weakly inhibited.2. Ag-CMCTS-TBZ not only shows excellent bacteriostasis, but also can prevent change in color of Ag~+, the defect that occurs in the monocomponent Ag antimicrobial agent, and can improve its water-solubility, while the molar ratio of Ag to sugar residues is between 1:100 and 6:100 , and that of TBZ to sugar residues is between 1:100 and 2:100, respectively.3. The antimicrobial assays to the typically representatives of bacteria and fungi, E. coli, S. aureus, A. niger , M. sp, showed that this new complex antimicrobial agent has integrated the antimicrobial characters of its monocomponent agents (CMCTS, Ag, TBZ) and bicomponents complex agents (CMCTS-Ag, CMCTS-TBZ), being able to broad-spectrally inhibit these chosen modeled bacteria and fungi. FT-IR assays showed that Ag and thiabendazole bind respectively to the amino group and carboxyl group of the CMCTS. The composition molar ratio of Ag-CMCTS-TBZ is: CMCTS:Ag:TBZ=100:57:13 or 100:37:5.4. The application assays to a water-soluble crylic acid latex coating agent showed that the antimicrobial paint, prepared by distributing Ag-CMCTS-TBZ to the coating agent, not only reserve all the qualities, e.g., color, polish, mucosity, odor and pH, but maintain the excellent bacteriostasis of the complex antimicrobial agent.