Return to Homework/Exam Page | Return to CM4650 Home Page
Homework 5 2008

CM4650 Polymer Rheology

    Due:  Wednesday, March 26, 2008 in class or by 5pm

    partial solution

    1.  (5 points)  6.3 (Question about tension-thinning)
    2.  (5 points)  6.7 (Which polymer has broadest MWD?)
    3.  (5 points)  In the step-shear strain experiment, we measure G(t,g).  In words, describe how G varies with time at constant strain.  Describe how G varies with strain g.
    4.  (5 points)  For a linear polymer of high molecular weight, what is the value of G' at high frequencies?  What is a typical value of the plateau modulus?  How does G' vary with frequency at low frequency?  How does G" vary with frequency at low frequency?
    5.  (20 points) 7.13  (Predict steady planar elongational flow material functions for PL GNF)
    6.  (20 points) 7.28 (flow down an inclined plane of a PL GNF)  Note that there are three parts to this question.
    7.  (30 points) 7.30 (tangential annular flow of a PL GNF)  Note that there are three parts to this question:  1)  calculate velcity and pressure profiles; 2) Calculate the torque required; 3) Plot the velocity field.



Return to Homework/Exam Page | Return to CM4650 Home Page