Study On The Structure And Antibacterial Properties Of Polymer/nano Zinc Oxide Syste

Nano-ZnO is widely studied in the field of food packaging as a new type of inorganic antibacterial agent because it is non-toxic,antibacterial and stable.In order to investigate its impact on properties of the polymer,this study used PBAT and LLDPE as matrix materials.Reinforced PBAT and LLDPE films with different weight percentages(1,3,and 5 wt%)of ZnO nanoparticles were prepared by the melt biending and casting process to investigate the effects of ZnO on the thermostability,crystallization behavior,mechanical,and antimicrobial properties of the PBAT and LLDPE films.In the system of the effects of ZnO reinforcement on the structure and properties of PBAT films,the results showed that the small amount of ZnO(1 wt%)reduced the decomposition temperature of the PBAT films by nearly 50 °C,and the thermal stability was significantly decreased with the increasing ZnO content.Melt flow index comparison showed that the ZnO nanoparticles accelerated the room temperature degradation rate of PBAT films.In addition,due to the degradation effect of ZnO nanoparticles,the mechanical properties such as the total percentage of elongation(at break),the tensile strength,and yield strength decreased with the addition of ZnO nanoparticles.The antibacterial test showed that PBAT+1wt% ZnO films could achieve high antibacterial activity(R=6.8)against E.coli.In the system of the effects of ZnO and zinc methoxide reinforcement on the structure and properties of LLDPE films,the SAXS results showed the particle size of methanol zinc was 30.26 nm and the particle size of ZnO was 27.24 nm.Melt flow index comparison showed that the addition of methanol zinc lead to the degradation of LLDPE to a certain extent.The addition of zinc methanol and nano-ZnO resulted in an increase in the crystallinity of LLDPE compared to the neat LLDPE,indicated that nanoparticles could promote the growth of LLDPE microcrystals.The surface roughness of LLDPE films was 256.1 nm,and the surface roughness of LLDPE/methanol zinc films was 271.3 nm,so the methanol zinc increased the surface roughness of LLDPE films.Therefore,the haze of LLDPE/ZnO,LLDPE/methanol zinc films increased.The antimicrobial test showed that the antibacterial rate of LLDPE/ZnO films against E.coli was 71.1%,the same amount(0.6‰)of zinc methanol could achieve higher antibacterial rate(>99.9%)and greater antibacterial zctivity(R=6.9).