Polyadditions of 1,2-bis[3-(1,3-dioxan-2-one-5-yl)-propylthio]ethane (B6CC) and 1,2-bis[4-(1,3-dioxolan-2-one-4-yl)-butylthio]ethane (B5CC) with 4,9-dioxadodecane-1,12-diamine were carried out. The reactivity of B6CC with the diamine was higher than that of B5CC. Additionally, B6CC gave a higher molecular weight polymer than B5CC. The reaction-rate constants of B6CC and B5CC at 30, 50, and 70 degreesC were evaluated as 0.70, 0.89, and 1.07 L/mol . h; and 0.03, 0.06, and 0.10 L/mol . h in N,N-dimethylacetamide (initial reagent concentration 0.5 M), respectively. The activation energies were estimated to be 9.2 and 24.9 kJ/mol in the reactions of B6CC and B5CC with the diamine, respectively. (C) 2001 John Wiley & Sons, Inc.