Study On The Preparation Of High Permeability Polyethylene Film And The Effect Of Minicucumber Preservation

Polyethylene?PE?is commonly used as packaging of fruits and vegetables,but its moisture permeability is poor,and the gas permeability is less than good.The preservation effect is not good.When packaging fruits and vegetables with high respiration rate,condensation and anaerobic respiration are easy to occur,which accelerates the decay of fruits and vegetables.The purpose of this study is to modify PE through melting and blending with PBAT which has high moisture permeability,so as to improve moisture permeability and gas permeability of PE.PE is the main,PE/PBAT blend films with PBAT ratio of 10%,20%and 30%were prepared by tape casting and blow molding,respectively.The mechanical properties,thermal properties,barrier properties and moisture permeability of the blend films were tested.Finally,it was applied to the experiment of cucumber preservation.The results show that the addition of PBAT can effectively improve the mechanical properties,air permeability and moisture permeability of PE.The water vapor transmittance of PE/30 PBAT-L film is 142.2%higher than PE film.The permeability ratio of CO₂ to O₂ increases from 3.3to 4.35.In the experiment of mini cucumber preservation,compared with the control group,Sealed packaging with PE/30PB-L film and PE/20PB-C film were suitable to maintain the postharvest quality of mini cucumber,the contents of VC and soluble solids were the highest,decline were slowest,and the color of mini cucumber were better than those of the control group.The weightlessness rate had been at a low level for a long time and had a good sensory quality.It could maintain the commodity quality for 38 d.The preservation effect was outstanding.Compared with PE/30PB-L film and PE/20PB-C film,the results showed that PE/30-PB-L film was more suitable for packaging cucumber in gas permeability and moisture permeability,after 20 days of storage,all indexes of cucumber were superior to PE/20PB-C group,suitable for long-term storage.The PE/20PB-C group has better flexibility,simpler fabrication,lower cost of equipment and materials,better production value and application prospect,and is more suitable for short-term storage or transportation packaging within 20 days.