Adding a small amount of a plasticizer is often a convenient way to modify the properties of a polymer. Plasticizers are low molecular weight additives that reduce the overall molecular weight of the polymer sample, thereby changing its properties like glass transition temperature, mechanical properties, and flow properties (important in processing). Calcium stearate (MW = 606 g/mol; assume monodisperse) can be used as a plasticizer for PVC.

(a) If 2% calcium stearate (by weight) is mixed with PVC having Mn = 25,000 g/mol and a polydispersity of 2.00, determine the extent to which Mn and Mw are modified by plasticization. (b) If the glass transition temperature and mechanical properties correlate primarily with Mn while flow behavior such as viscosity correlates primarily with Mw, which will be most affected by plasticization, processing properties or end-use properties?