Preparation And Properties Of Nano-ZnO/AESO Pickering Emulsion And Its Functional Foam

Foam packaging materials must not only consider product safety and environmental issues,but also consider the development and utilization of raw materials.Commonly used petroleum-based foam packaging materials are difficult to degrade and produce white pollution.Therefore,environmentally friendly biomass packaging foam materials are an inevitable trend in the development of modern packaging.Soybean oil-based functional foam prepared by the Pickering emulsion template method not only avoids the pollution and migration caused by the traditional foaming agent,but also gives the foam packaging material a new function.In this paper,a stable Pickering emulsion was prepared by using zinc oxide nanoparticles(ZnO)with good antibacterial property as a stabilizer and soybean oil derivative acrylate epoxidized soybean oil(AESO)as the oil phase.The thermosetting AESO-ZnO composite biomass foam was prepared by Pickering emulsion template method,and its properties and influencing factors were studied.The following are the main contents and conclusions of this article:(1)Preparation and antibacterial discussion of zinc oxide nanoparticles:Preparation of zinc oxide nanoparticles by hydrothermal synthesis,study the effects of hydrothermal time,hydrothermal temperature and precursor concentration on the morphology and particle size of zinc oxide nanoparticles,and through nano-particle size analysis and SEM analysis,it was found that the reaction conditions had an important effect on the particle size and morphology of the zinc oxide nanoparticles.On the basis of single factor experiment,the response surface combination experiment was designed,and the inhibition zone was used as the response value to optimize the preparation conditions of zinc oxide nanoparticles with the best antibacterial property.The optimal conditions were determined:the hydrothermal reaction temperature was 111 ?.The hydrothermal reaction time was 10 h,and the concentration of zinc acetate was 0.02 mol/L.The zinc oxide nanoparticles prepared under these conditions had an inhibition zone against Escherichia coli of 17.3 mm.(2)Preparation of acrylate epoxidized soybean Oil:Epoxidized soybean oil(ESO)and acrylic acid(AA)were used as raw materials to prepare acrylate epoxidized soybean oil.The carboxylic acid and epoxy groups were confirmed by NMR and FI-IR analysis.The esterification rate of the obtained product was 97%.(3)Pickering emulsion preparation:Pickering emulsion was prepared by using AESO as oil phase and nanometer ZnO as stabilizer.The type of emulsion obtained by conductivity method and dilution method was proved to be water-in-oil type;the effects of the concentration of solid particles and oil-water ratio on the particle size and stability of the emulsion were investigated.The optimum ratio of raw materials was determined as follows:the solid particles were added in an amount of 1.0 wt%,and the oil-water ratio was 3:2 or 1:1.The Pickering emulsion prepared under these conditions has good stability and a small droplet size,and it is found that the solid particles stabilize the emulsion in a manner of adsorbing at the oil-water interface to form a granular film.(4)Preparation of thermosetting AESO-ZnO composite foam by Pickering emulsion template method:under the conditions of initiator and heating,the oil phase AESO in the emulsion is solidified by free radical polymerization,and the water phase is vaporized and foamed,an AESO-ZnO composite foam was obtained.The effects of initiator concentration,reaction temperature and reaction time on foam density,conversion,porosity,pore size,stress-strain curve,compressive strength and elastic modulus were investigated.The following is the best preparation process conditions:the initiator concentration is 10%,the reaction temperature is 120 ?,and the reaction time is 3h.The reaction time was found to be an insignificant factor in the preparation of the foam.Through the SEM analysis of the cross-section of the foam,the obtained foam cells have larger cells,lower porosity and there is a collapse of the cells.The foam has good antibacterial activity and the inhibition rate against Escherichia coli reaches 99%.