Diffusion Behavior Study And Simulation Of Plasticizer In Polymer

When a polymer film containing plasticizer contacts with an adhesive,the plasticizer will diffuse into the adhesive,causing the properties of the adhesive layer changing gradually.Therefore,the study of the diffusion behavior of plasticizers in adhesives has important industrial application value.In this paper,a kind of polyacrylate pressure sensitive adhesive was prepared by solution polymerization.The blends of polyacrylate and DEHP were prepared,and the mass fraction of DEHP was 0-100%.Then the standard curve fitting from peak area A1726/A1267 and mass fraction of DEHP was drawn using data from ATR-FTIR test.Pressure sensitive adhesive film with thickness of 50?m was prepared by coating.It was compounded with DEHP,then the diffusion behavior of DEHP in the film was monitored by ATR-FTIR.The diffusion coefficients of DEHP in polyvinyl chloride and polyacrylate were calculated by molecular dynamics.The influence of temperature and polymerization degree on diffusion coefficient was studied,and the change of diffusion coefficient was analyzed by free volume theory.Several assumptions were put forward based on the structure of diffusion experiment,leading to a simplified single-layer model.The mathematical description of the single-layer model was made,and the determining question was solved by programming with the difference quotient method.Finally,according to the three-layer structure of polyvinyl chloride film,polyacrylate pressure sensitive adhesive and adherend used in industry,after reasonable simplification,a double-layer model was established,and the mathematical description of the double-layer model was made.The determining question was solved by programming using difference quotient method,thus the diffusion behavior of DEHP in the three-layer structure was predicted.