Study On Preparation And Performance Of PE-based Nano Packaging Material

Polyethylene(PE) is a kind of resin that widely used as sub layer of composite material or substrate material for modification in the field of packaging. The nano particle which with the special surface effects and the size effect, will have an impact not only on the strength and barrier properties, but also give special performance such as antibacterial property to material when mix or coat with PE. These will play a key role in extension the shelf life of the product. In recent years, packaging and storing technology for preservation was put forward a higher requirement by the soaring amount of regional circulation for upscale seasonal fruits and vegetables. Therefore, PE-based nano packaging material was prepared in this study that aims to develop new packaging materials with comprehensive antibacterial and preservative performance.In this study, nano- Zinc oxide and nano- Titanium dioxide are modified by coupling agent, using Infrared Spectroscopy and Transmission Electron Microscope to characterize the changes about chemical groups, surface structure and property of the nano powder. Prepare the PVA Sol to make PVA nano-ZnO/PE and PVA nano-TiO2/PE films by coating method. Research and analysis the film’s mechanical, barrier and antibacterial properties by using Electronic universal testing machine, Oxygen permeability tester, Water vapor permeability tester and Foil method. Then new modification method that rare earth dope for nano-particles was put forward to the weakness of composite film, and prepare the new film for further study and analysis. During the experiment, PE film coated rare earth cerium doped ZnO(Ce4+-ZnO) and PE film coated rare earth cerium doped TiO2(Ce4+-Ti O2) were prepare for characterize the mechanical and barrier properties, antibacterial effects as well select some fresh fruits and vegetables as specific contents to research the preservation effect of the film.The results show that KH570 give a good modification effect to nano-ZnO and NDZ101 is more suitable for modification of TiO2. the PVA nano-ZnO/PE and PVA nano-TiO2/PE films can get good mechanical performance when content of the nano-powder is around 1%, and barrier properties reach the optimal point when content of the nano-powder is about 1.5%; The antibacterial rate of PVA nano-Zn O/PE film is over 90% under the different conditions that protected from light, natural light and UV light, and antibacterial rate of PVA nano-TiO2/PE films is over 97% under natural light and UV light. The new film that coated the rare earth doped nano-particle in this study show a better antibacterial properties and practical preservation performance compared with the film coated coupling agent modified nano-particle. The fruit rot and water loss during the storage of Cherry can be effectively inhibit by new composite film, so that prolong the shelf life from the days of 7 to more than 19; The new film also can slow down the browning, autolysis, cap-opening and other phenomena during the storage of Tricholoma Matsutake, and to extended the shelf life from the days of 3 to around 7.