Preparation and properties of bio-based gallic epoxy resin/nano-ZnO antibacterial coating

Bio-based gallic acid epoxy resin(GAER)was prepared by gallic acid as main raw material. Nano-ZnO surface modification by KH-550 was used to prepare KH550-nano-ZnO. In addition, it was combined with the bio gallic acid epoxy resin(GAER) GAER/KH550-nano-ZnO composite coating was prepared by using succinic anhydride as curing agent. The changes of microstructure before and after modification of nano-ZnO were characterized. The curing process of succinic anhydride/GAER system was studied by differential scanning calorimeter. The effects of the KH550-nano-ZnO content on the mechanical properties, the thermal properties, dynamic mechanical properties and the antibacterial properties of the coating film were tested. The results show that the addition of proper amount of KH550-nano-ZnO can increase the glass transition temperature (T-g) of the system and improve the impact resistance of coating surface. The hardness and thermal stability of the coating are increased and the adhesion is decreased with the increased content of KH550-nano-ZnO. The initial thermal decomposition temperature (7(5%)) of the composite coating is higher 12. 6-15. 4 degrees C than that of pure GAER. When the content of KH550-nano-ZnO is 2%(mass fraction), the T-g is increased by 30. 7 degrees C compared with pure GAER resin. The anti-bacterial rate of the KH550-nano-ZnO/GAER cured coating to Escherichia coli and Staphylococcus aureus reaches 99. 99%.