| Abstract: | A new parameter α3 for characterization of the skewness of a polymer's molecular weight distribution (MWD) based on the statistics is introduced. For α3 > 0, the skewness is positive, characterizing the MWD with a tail at higher-MW side. For α3 = 0, the MWD is symmetric. For α3 < 0, the skewness is negative, characterizing the MWD with a tail at the lower-MW side. A relationship between α3 and the first four (from zeroth to third) moments of the MWD is developed which allows calculation of the skewness without detailed calculation of the MWD. An example of polymerization of styrene with n-butyllithium is given to demonstrate the characteristics of α3. |
