Preparation And Properties Of Novel Pullulan Antibacterial Food Packaging Films

The natural pullulan can be modified by molecular modification to produce a modified food packaging film,which can be used as a food packaging material to solve the problems of poor antibacterial performance of natural polysaccharide food packaging materials and high non-natural chemical polymer food packaging material infiltration toxicity,and difficult to be degraded Problems,to achieve complementary performance advantages.This study selected high-gas barrier properties pullulan as raw materials,its secondary chemical molecular modification,design and synthesis of three different series of antibacterial diamine aminated polyallyl pullulan,and innovative and film formation A new type of antibacterial pullulan polysaccharide food packaging film was prepared by combining natural sodium alginate and chitosan with different concentration ratios,and the infrared spectrum,thickness,water vapor transmission rate,optical performance,and mechanical properties of the composite film were also studied.Material properties such as performance and antibacterial properties were thoroughly and thoroughly studied.This study provides a theoretical basis for the development of a novel antimicrobial Pullulan food packaging material,provides new ideas for the development of green,safe,and degradable food packaging materials,and provides for the deep processing and utilization of natural polymer polysaccharides in the food packaging field.The experimental basis.The main research content is as follows: First,natural pullulan with high gas barrier properties is used as raw material,and two different methods are used to independently synthesize different structural new compounds: 1)introduction of active aldehyde groups on the surface of pullulan by oxidation of sodium periodate to obtain polyacyl pullulan(OxPullulan);2)respectively with aliphatic diamine hexamethylenediamine(HMDA),steroidal diamines Adipic acid dihydrazide(ADH)and enamine diamine diethylenetriamine(DETA)were grafted on the surface of the polyacetal pullulan molecule by reductive amination to form diamine-type pullulan.Derivatives-Antibacterial bisamine-amined polyacetal pullulan.The structures of the novel antibacterial bisamine-amined polyacetal pullulan were characterized by FTIR,1H NMR,XRD and TG-DTA.They were HMDA-Ox Pullulan,ADH-OxPullulan,DETA-Ox Pullulan.Ultrasound-assisted solution casting method was used to synthesize antibacterial bisamine aminated polyacetal pullulan polysaccharides and naturally occurring macromolecular polysaccharides with better film forming properties such as sodium alginate and chitosan at different concentrations to prepare novel antibacterial agents.Pullulan food packaging film,they are ADH-OxPullulan/SA?ADH-OxPullulan/CS?HMDA-OxPullulan/SA?DETA-Ox Pullulan/SA?DETA-OxPulluln/CS.Through FTIR,WVP,UV-Vis,SEM and other characterization methods,the in-depth structure-activity relationship of the internal bonding method,water vapor transmission rate,optical properties and surface morphology of the composite membrane was investigated,and the natural polysaccharide(sodium alginate,The incorporation of chitosan has a close relationship with membrane thickness,water vapor transmission rate,mechanical properties and surface morphology,ie,the incorporation of natural polysaccharides can help reduce the water vapor transmission rate of the composite membrane and enhance water resistance.It can reduce the thickness of the composite film and enhance its mechanical properties.The HMDA-Ox Pullulan/SA composite membrane is the thinnest,the DETA-OxPullulan/CS composite membrane has the lowest water vapor transmission rate,and the ADH membrane has the best light-blocking performance.The mechanical properties of the ADH-OxPullulan/SA composite membrane are optimal.We study,analyze and prepare optimal performance membranes from multiple perspectives.Based on this,in the application research of food packaging film materials,Staphylococcus aureus and Escherichia coli were respectively used as representatives of Gram-positive and Gram-negative bacteria to study different molecular structures,different compounding materials and different compounding proportions.Food packaging film has a certain antibacterial properties.This research finally obtained a new type of natural polysaccharide antibacterial food packaging material that combines safety,low toxicity,high biodegradability,life-friendly and safe use,safe and green environmental protection,and excellent mechanical properties.It can be widely used as a food packaging film.