poly(vinyl acetate) is extruded at 180C at a constant temperature through a capillary rheometer having a...

 

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poly(vinyl acetate) is extruded at 180°C at a constant temperature through a capillary rheometer having a ram (reservoir) diameter of 0.375 in. and a capillary with an inside diameter of 0.041 in. and a length of 0.622 in. The data provided give the efflux time to extrude 0.0737 in³. at different ram loads. using the following data: Ram Load (lb) 97.5 Efflux time (min) 5.32 145 217 250 1.58 0.31 0.17 (a) Determine the power-law parameters n and m for PVAC and state all assumptions used to obtain your results. (b) plot the apparent viscosity, ", in units of Pa-s versus the nominal shear rate at the wall, logarithmic coordinates. yw(s-1) , using poly(vinyl acetate) is extruded at 180°C at a constant temperature through a capillary rheometer having a ram (reservoir) diameter of 0.375 in. and a capillary with an inside diameter of 0.041 in. and a length of 0.622 in. The data provided give the efflux time to extrude 0.0737 in³. at different ram loads. using the following data: Ram Load (lb) 97.5 Efflux time (min) 5.32 145 217 250 1.58 0.31 0.17 (a) Determine the power-law parameters n and m for PVAC and state all assumptions used to obtain your results. (b) plot the apparent viscosity, ", in units of Pa-s versus the nominal shear rate at the wall, logarithmic coordinates. yw(s-1) , using