Study On Preparation,Properties And Anti-migration Ability Of SiO_x/PET Composite Films

Plastic packaging materials may interact with food when in direct contact with each other.It can reduce the shelf life of food and cause the safety issues about the plastic components to food migration,so the development and application of barrier packaging materials are imperative.Now,the PET plastic packaging material deposited SiOx barrier is gradually concerned with its excellent barrier property.In this paper,in order to clarify the principle of barrier property of SiOx layer and its anti-migration principle for migration components in plastics,the self-made SiOx/PET composite films were used to study the barrier properties and the migration of additives in plastics to food simulants,and the main results are as follows:(1)The thermal,mechanical and barrier properties of SiOX/PET composite films were improved by the SiOx layer.Compared with PET film,the Tg of SiOx/PET composite film was increased with the increase of thickness of SiOx layer,but its growth rate was gradually decreased.The tensile strength and the elongation at break of SiOx/PET composite films were increased first and then decreased,specifically the tensile strength was increased by 5.5%to 25.0%,the elongation at break was increased by 9.3%to 20.6%.The barrier properties of oxygen and water vapor were obviously improved and then the trend were gradually gentle,specifically the oxygen transmission rate was reduced by 7.7%to 79.3%and the water vapor transmission rate was reduced by 46.0%to 77.3%.(2)SiOx layer had anti-migration effect on small molecular plasticizer DOP in SiOx/PET composite film.When the thickness of the SiOx layer was 40nm-320nm,the specific migration amount of the plasticizer DOP in the composite film to the food simulants was reduced by 11.40%-90.0%at 20?,about 18.8%-87.5%reduction at 40? and 17.7%to 85.0%reduction at 70?.When the thickness of SiOx layer was sufficient,the factors such as food simulant and migration temperature had little effect on the migration of plasticizer in the ffilm.(3)SiOx layer had anti-migration effect on antioxidant 1010 in SiOx/PET composite film.The migration of the antioxidant 1010 was detected only in the food simulant Dl.When the thickness of the SiOx layer was 40nm-320nm,the specific migration of the antioxidant 1010 to the food simulant D1 was reduced by 69.8%-82.6%under the condition of 20?,about 37.5%-40.6%reduction at 40? and about 33.8%-63.2%reduction at 70?.(4)The migration time,temperature and food simulant had effect on the migration of the additives(plasticizer DOP and antioxidant 1010)in the composite film.When the film was directly contact with the food simulant,the pre-migration of the additive grew faster and then gradually equilibrates.Meanwhile,under the same food simulant but different temperature,the migration rate was increased with the increase of the migration temperature,and the specific migrations from large to small in turn were 70?>40?>20?.At the same temperature conditions and film,the specific migrations of plasticizer according to the food simulant from large to small in turn were the food simulant D1>the food simulant C>the food simulant A>the food simulant B.(5)The migration prediction model of Wei-bull-SiOx/PET double layer material was established,and the migration behavior of small molecule plasticizer could be predicted under certain conditions.