Development of Simulation Technique of Flow and Structure Formation for Polymeric Blended Materials

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For the purpose of clarification of relation between morphology, molecular dynamics and rheological properties, we developed the simulation program to predict the rheological properties by the molecular dynamics method using the Bead-Spring model and Tube model. The simulation results qualitatively presented the shear-rate dependence on the first normal stress difference and shear viscosity, which was seen for the actual polymer melts.We formulated the simulation model of deformation and breakup or a single droplet using only the physical properties or a droplet and a matrix liquid. It achieved success to represent the breakup of a droplet by the simulation, which has been impossible by means or the method or continuum mechanics. We performed the simulation for Newtonian-Newtonian system in the simple shearing flow field and its results were compared with the experimental observation. The simulation results showed the mode or breakup and the dependence or phisical properties on it, see … More n in the experiment. But the time-course of deformation and breakup in the simulation was not in agreement with experimental one.In the view point or macroscopic treatment, we developed the computer program of optimum determination of model parameters for the viscoelastic constitutive equations which could relatively well predict the behavior or polymer liquids, and studied the prediction accuracy or each model. Using these constitutive models, we carried out the viscoelastic flow analyses for the extrudate swell from the various shaped dies and film casting process. The several new informations on flow mechanism could be obtained, for example, requirement or consideration of irreversibility in reversed deformation for the extrudate swell problem, importance of ratio or extension-thickening nature in the uni-axial elongation to that in the planar elongation, etc. Also, three-dimensional analysis program or viscoelastic flow including the free surface was developed and the extrudate swell from the square channel in the low shear rate region was analyzed. Less