Preparation And Performance Study Of PET Composite Film With Anti-fog And Light Energy Conversion Functions

The photoecological agricultural film can convert the blue-green light and ultraviolet light that are harmful or non-absorbed to plants into the red-orange and blue-violet light required for plant photosynthesis under the irradiation of ultraviolet light,thereby achieving the purpose of increasing plant yield.Polyethylene terephthalate(PET)film is widely used in various industries due to its excellent mechanical properties and weather resistance.However,due to its poor hydrophilicity on the surface,the fogging phenomenon on the surface of PET film is more serious,which greatly limits the application of PET film.Easy to atomize agricultural film is not conducive to the production of crops.Water droplets generated by atomization hinder the transmission of light,reduce the light transmittance of agricultural films,cause various pests and diseases,and affect the yield and quality of crops.In order to promote the application of PET films on photoecological agricultural films,this thesis focuses on anti-fog droplets on the surface of PET films and the modification of light energy conversion functions.A series of PET composite films have been successfully prepared.The research contents are as follows:(1)Polyvinyl alcohol with good hydrophilicity(PVA)and organic rare earth complexes with light energy conversion function were introduced into the PET substrate film by a coating method to prepare a dual-function PET composite with high efficiency of anti-fog and light energy conversion film and explore the best coating process.The structure of the hydrophilic layer of the composite film was characterized by FT-IR,and the optical microscope photos showed that the coating was relatively uniform.The anti-fog test shows that the PET composite film has efficient anti-fog performance.The composite film remains transparent for more than 10 hours in a water vapor environment of 60°C.The fluorescence intensity and fluorescence lifetime tests show that the prepared sample has a good light energy conversion function,and the PET composite film shows bright red light under ultraviolet light irradiation,which is beneficial to the photosynthesis of plants.(2)By chemical grafting and physical coating,acrylic(AA),PVA and organic rare earth complexes were introduced onto the surface of PET films to prepare a dual-functional PET composite film with hydrophilic anti-fog and light energy conversion functions.The structure of the hydrophilic layer of the composite film was characterized by FT-IR,showing that the PET-AA-PVA film was successfully prepared.Based on the original good anti-fog and light energy conversion functions,the chemically modified samples have better durability.(3)A water-absorbing substance and an organic rare-earth complex with a light energy conversion function are introduced into a PET substrate film by a coating method,and a dual-function PET composite film having super water absorption and light energy conversion functions is prepared.The water contact angle is measured It shows that it has excellent water absorption.Optical microscope photos show that the surface of the composite film is very uniform.In addition to the original good anti-fog and light energy conversion function basis,the water absorption rate can reach about 20%.