The viscosity and shear modulus of solutions of polyethylene glycol (PEG) with different molecular weights near a solid substrate were studied using a quartz crystal resonator technique. The technique probes the solution boundary layer with a thickness of about the viscous penetration depth adjacent to the surface of the quartz crystal. On the basis of the resonant frequency shift and the dissipation broadening of the quartz crystal resonator, the viscosity and shear modulus of the solution boundary layers as a function of the concentration and the molecular weight of PEG molecules are determined. The results show that, near the semidilute concentration of the solution, the viscosity of the boundary layer increases rapidly; the rise of the viscosity follows a power law with an exponent which depends on the molecular weight of PEG molecules. For solution boundary layers consisting of larger PEG molecules, their shear moduli display a rapid increase above the semidilute concentration also. The implications of these results are discussed.

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The mathematic model for polymer extrusion has been established by using the penalty finite element method, and the analysis program has been coded. The driven and pressure flow of power-law fluid in compound shaped part of co-extrusion process of polymer with metal insert has been simulated. The velocity field and temperature field of polymer flow in die cavity are obtained though solving the momentum equation and energy equation, and the influence of various metal insert velocity on the polymer flow is studied. The potential defect is forecast, and the improved measure has been given further. It shows that the common rule of the compound shaped part of co-extrusion process of polymer with metal insert is given by the analysis of the example. The simulation results are very important for the process and die design of the polymer co-extrusion with metal insert.