| Abstract: | In this paper, a model is developed for determining the average properties of block copolymers formed via the one‐prepolymer and the two‐prepolymer methods. A knowledge of the average properties of reacting prepolymers, instead of their whole molecular weight distribution (MWD), is sufficient to calculate the desired average molecular weights of the resultant block copolymers. Mn, Mw and polydispersity index (PI) of the block copolymers formed via the one‐prepolymer and two‐prepolymer are studied in detail for comparison. The simulation results indicate that Mn,1p < Mn,2p and Mw,1p < Mw,2p in the range 0 ≤ α < 1, while Mn,1p = Mn,2p and Mw,1p = Mw,2p when α = 1. In addition, the conversion (α) does not significantly influence PI2p, while PI1p decreases linearly with increasing α. The results also show that PI1p > PI2p in the range 0 ≤ α < 1. Finally, PI1p and PI2p approach the same value at α = 1. This indicates that the polydispersity of the block copolymers formed via the two‐prepolymer method is usually narrower than that of the block copolymers formed via the one‐prepolymer method. |
