Study On Preparation And Properties Of Lecithin Modified Polymer Packaging Film

Phospholipids are the main components of the bio-membrane.Phospholipids are also natural amphiphilic molecules.They have a wide range of sources and excellent performance.However,the application of phospholipids is relatively limited.The polymer packaging film has low surface energy and poor hydrophilicity,so oil and protein are easy to be absorbed on its surface,which results in waste and reduced efficiency.The use of lecithin modified polymer packaging film can improve the anti-adhesion performance of the packaging film and can expand the application of phospholipids,which is significant.In this paper,I use coating method and UV cross-linking modification method to modify polymer packaging film.Coating method refers to the use of polyvinyl alcohol(PVA),epoxidized lecithin(EPL),nano-PTFE particles(PTFE NPs),which formulate water-based paint coating on polyester(PET)film to improve the Oil Repellency and Hydrophobicity;UV crosslinking modification method refers to graft lecithin layer on the surface of the film to improve hydrophilicity and anti-protein adhesion.The preparation of EPL and PET films and PVA coating fluids were first performed.The epoxidation modification of soybean phospholipids is the epoxidation of the unsaturated double bonds in the non-polar tail of phospholipids.The results of experimental indicated by epoxy values show the preferred reaction conditions for the preparation of EPL are:reaction time 6 h,hydrogen peroxide dosage 30%-40%,reaction temperature 60°C,acetic acid dosage 5%-6%,catalyst amount8%-11%;through the corona strength test of PET film and PVA coating fluid standing experiment,we know the optimum corona strength of the base film is 30 V/m~2,and the concentration range of the PVA coating fluid is 10%-12%.Then goes to make the preparation of PVA/EPL/PTFE NPs waterborne coating and performance tests.The hexadecane CA of the coating on the PET film is used as an index.The single-factor experiment and orthogonal experiment show that the optimal formula of the water-based paint are:PVA concentration is 11%,EPL concentration is 5%,and PTFE NPs concentration is 4%,the hexadecane CA is 78°,which indicates that the coating has a certain degree of oil repellency;the water CA test shows that the coating is superhydrophobic,and the self-cleaning test shows a good self-cleaning,adhesion and stability test show that the coating has strong adhesion and stable performance.At the end of this paper,make the preparation of lecithin modified PE film and performance tests.The water CA of the modified PE film is used as the index.The single factor experiment and orthogonal experiment show the optimum conditions are:lecithin concentration is 5wt%,vacuum drying time is 1 hour,the photoinitiator ITX concentration is 3wt%,UV light is 45 minutes,the lecithin modified PE film obtain the excellent hydrophilic properties,the ELISA test shows that the a good resistance to protein adhesion,the stability test shows that the film surface grafts phospholipid modified layer,which performance is stable.