| Biodegradable Copolyester which perform excellent biocompatibility and biodegradation have been applied in the fields of food packaging, agricultural films, medical devices and daily used goods, they are hopeful to replace polyolefin in some application fields. The surface of biodegradable polyester material is easily infected with bacteria, viruses and other microbes, therefore make people infected and damage health, which limit their widely use in the fields of toys and packaging materials. A lot of interest focuses on the development of antibacterial biodegradable material.Grafting copolymerization or melting blending method by physical added bacteriostasis component are usually used to ensure polymer antibacterial performance. Especially adding inorganic nanoparticles or organic antibacterial agent into the polymer materials have become one of research hot spots.In this work, triazoles and zinc complexes bacteriostatic agent (Zntrs) are synthesized with triazole, succinic acid as ligand, inorganic metal ions, zinc as central coordination atoms. It is conducted a preliminary characterization. The antibacterial composites are prepared with Zntrs and zinc oxide antibacterial agent as fillers, which added to the biodegradable polyester PBS and PLA by melt blending method respectively. The effect of bacteriostatic agent on inhibiting the growth of escherichia coli of PLA or PBS has been researched.FT-IR, EDS and SEM are used to systematically discuss the influence of nano zinc oxide (nano-ZnO) and zinc oxide whisker (T-ZnO) on bacteriostatic properties and mechanical properties of PLA composites, the thermal degradation behaviors of the composites were analysized using TGA. Antibacterial efficiency are investigated with the method of bacteriostatic circle and lamination in antibacterial test. Degradation performance of the PLA and PBS bacteriostasis material under the condition of acid, alkali, ammonia solution are investigated.The results show that the Zntrs bacteriostatic agent can give PBS strong ability to inhibit the growth of escherichia coli, adding10wt%Zntrs bacteriostatic agent can make antibacterial rate of PBS reach to92.9%on E. coli. However, it has low thermal stability which is not suitable for PLA materials that has high processing temperature. Zinc oxide can give the PLA materials excellent antibacterial properties, the antibacterial efficiency of nano-ZnO is higher than T-ZnO.The dispersity of nano-ZnO particles in the PLA matrix and interface compatibility of ZnO/PLA composite materials are improved after the surface of ZnO modified by silicon coupling agent KH550, at the same time, the bacteriostatic rate of nano-ZnO/PLA composites containing3wt%nano-ZnO on E. coli increases from81.3%to98.7%, the antibacterial rate of T-ZnO/PLA composite materials increases from67.3%to85.3%. After surface treatment by silane coupling agent KH-550, the nano-ZnO particles will cover the catalytic activity point on the surface of nano-ZnO, the reaction of thermal degradation on PLA are inhibited by nano-ZnO, however, the reaction of thermal degradation are enhanced by T-ZnO after whose surface are modified.The degradation rates of PLA and PBS antibacterial materials in acid, alkali, ammonia are faster than that of pure PLA and PBS. The properties of biodegradable polyester materials have a tendency to reduce after a period of time of degradation in alkali and ammonia. The present work aims at the experimental support for the preparation of antibacterial biodegradable polyesters. This dissertation should have positive significance in biodegradable polyester materials replacing general polymers and protecting environment. |
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