Study On The Structure And Gas Barrier Properties Of Silicone Coating On The PET Film

With the continuous improvement of people’s living standards,the application of the functional food packaging film is becoming more and more extensive,and the gas barrier packaging film has always been a hot spot of the research.Among them,PET has excellent properties and is widely used in food packaging film.In order to improve the gas barrier property of PET film,a kind of the UV-thermal double curing coating with high adhesion and high crosslinking degree and the modification of a barrier layer material are studied in this paper.And the combination of the two is to prepare a kind of high resistance coating.The preparation of light-heat double curing coating is based onγ-glycidyl methoxypropyl trimethoxy silane andγ-methacryl propyl trimethoxy silane as the main raw material,polyether amine D230 as a thermal curing agent,benzophenone as a photoinitiator,Methacrylic acid N,N-dimethylamino ethyl ester as a co initiator,epoxy resin as an adhesion enhancer,HDDA as a reactive dilute agent and trimethylolpropane triacrylate as a crosslinking agent.The curing reaction was conducted under UV irradiation and thermal initiation.The process of heat curing and light curing was studied.The advantages of high crosslinking degree and short curing time of light curing and excellent adhesion of heat curing were retained.And a kind of coating of high adhesion grade of 0 and high crosslinking degree of 90.27%was prepared.In order to obtain barrier coatings,a sericite with lamellar structure was added in the coating.Lamellar sericite has excellent physical and chemical properties,and is often used as a lamellar filler in coatings.But sericite has a more stable structure and has no expansion layer itself.In order to give full play to the advantage of layered structure itself and make it dispersed evenly in the coating system,the lamellar sericite is modified in this paper,including two steps of the structure activation and the intercalation treatment.Moreover,the modifie d mica was characterized by ATR and XRD,and the lamellar mica with 1.053 nm spacing and good compatibility is obtained.Combined with the two materials prepared above,the modified lamellar mica was used as a barrier material to increase the gas barrier p roperties of the PET film by adding in a silicon coating with UV-thermal double curing.The results showed that its success of hindering the direct penetration of gas molecules,making the gas entering the "loop",prolonging its penetration path,and thus effectively realizing the high gas barrier performance.The moisture permeability of the PET film after coating modification reached 12.4033 g/(m2·24h),and the permeability reached29.9097 cm~3/(m~2·24h·0.1m Pa),there is a good application in the field of food packaging...