Continuous Free‐Radical Polymerization with Long‐Chain Branching and Scission in a Tanks‐in‐Series Model

Free‐radical polymerization that involves the polymer transfer reactions, leading to both long‐chain branching and scission, as in the cases of high‐pressure ethylene polymerization, is considered for a tanks‐in‐series model. In a tanks‐in‐series model, the residence time distribution (RTD) becomes narrower to approach that for a plug flow reactor (PFR), as the number of tanks, N increases. The molecular weight distribution approaches rather quickly to that for a PFR, as the N ‐value increases. On the other hand, the branching density and the radius of gyration of highly branched polymers may show clear differences from that for a PFR, even when N ‐value is as large as 20. The present theoretical approach would provide great insight into the continuous production processes having complex RTDs.