Theory of Polymer Mass Moments for the Polycondensation Reaction of A_a-B_bType

By means of the differentiation method proposed by Tang Auchin, the recursion formula for evaluating the kth polymer moment in which the polymer mass is involved is obtained holding true for both pre-gel and post-gel. Taking advantage of the recursion formula, the number-, weight-and Z-average molecular weight of polymers can be caculated without difficulty.