Study On The Preparation And Characteristic Of PLA/PBAT Composite Packaging Film And The Migration Of Its Additives To Food Simulants

Three kinds of PLA/PBAT films with different ratio of 10/90,20/80 and 30/70were prepared by melt mixing,extrusion granulation and blowing.The influence of different PLA/PBAT proportions on the mechanical properties,barrier properties and transmittance of PLA/PBAT films were investigated and discussed.It was found that30/70?PLA/PBAT?film have the best mechanical properties,barrier properties.Finally,the mechanical properties and the inner structure of the films after UV aging were studied,finding that UV aging caused the membrane ester bond breaking,and the mechanical properties are reduced greatly.The detection method of plasticizer ATBC was established by gas chromatography mass spectrometry?GC-MS?.The initial content of ATBC in the film was detected.The influence of different proportions and UV aging time on the migration of ATBC in composite films was investigated and explained by SEM.It is found that the migration rate of ATBC from PLA/PBAT=30/70 film is the lowest,which with the highest crystallinity.While UV aging can reduce ATBC migration rate by 15%as some densification appeared.PLA/PBAT/CaCO₃/erucamide was blended with the mass ratio of 10/70/20/1,then 0.5%of nanometer-sized ZnO,TiO₂ or SiO₂ were added seperately,these three different nano-composite films were prepared by melt compounding and blow molding.At the same time,two blank films without nanocomponents or erucamide were prepared to compare.The influences of different nanomaterials on mechanical properties,barrier properties and UV transmittance of PLA/PBAT/CaCO₃ films were investigated and discussed.The results showed that three kinds of nanometer-sized component reduced the mechanical properties and UV transmittance,improved the barrier properties.A method for the detection of erucamide was established,and the standard curve equations of erucamide in four different food simulants were established.The initial content of erucamide in the films was detected after dissolving the films.The migration of erucamide into isooctane,95%ethanol,100%ethanol was studied.The influence of different food simulants and three nanoscale components?ZnO,TiO₂and SiO₂?on the migration of erucamide were analyzed.The results showed that the migration into the alcohol is the biggest,with the maximum dissolution of film;nano-components redused the migration of erucamide,rank:TiO₂>SiO₂>ZnO.