Preparation And Application Of Atmosphere Preservation And Water Soluble Film

Since the beginning of the 21 st century,the use of plastic films has been extremely large,and mainly based on various non-degradable petroleum-based plastic films.To effectively mitigate and solve the problem of white pollution,the development of environmentally friendly degradable plastics is imperative.In this project,PVA/starch water-adjustable water-soluble film was prepared by solution casting method.It was modified with synthetic ZIF-8 to optimize the gas selective permeability of PVA/starch membrane.The main research contents are as follows:(1)Potato starch and corn starch were used to mixed with PVA to make films respectively,the microscopic morphology and mechanical properties were observed with optical microscope and universal tensile machine.The results show that the compatibility between potato starch and PVA is not good,and its tensile strength and elongation at break are very low.Therefore,corn starch and PVA was selected to form a film.(2)In order to improve the mechanical properties of the film,the PVA/starch film was plasticized and reinforced with 1,4-butanediol and methyl cellulose respectively.The mechanical properties,thermal stability and glass transition temperature of the film were tested,the results show that the performance of the film is the best when the content of 1,4-butanediol is 40% and the content of methyl cellulose was 5%.(3)The zeolite-like imidazole skeleton compound(ZIF-8)was synthesized by solvothermal method.Scanning electron micrographs showed that the synthesized ZIF-8 particles had an irregular polyhedron shape with a particle size of about 90 nm.ZIF-8 was post-modified with ethylenediamine,and the effects of modification time,modification temperature and modifier dosage on its performance were explored.The results showed that when the dosage of modifier was 7%,modified at 60? for 2 hours is best.(4)The gas permeability of PVA/starch film is modified with ZIF-8,and the gas permeability is characterized by the water vapor and oxygen permeability.The results show that after the introduction of ZIF-8 particles,with the increase of particle content,the oxygen and water vapor transmission rates of the atmosphere preservation and water soluble film both increase first and then decrease.When the amount of ZIF-8 particles is 0.01%,the gas permeability of the atmosphere preservation and water soluble film is the highest.