Semicrystalline network polymers were obtained by the DielsAlder (DA) reaction of furyl-telechelic poly(e-caprolactone) and tris(2-maleimide ethyl)amine. Controlling the rates of crystallization and crosslinking reaction gave materials with various properties. Curing at a temperature much below Tm of poly(e-caprolactone), at which crystallization proceeded first followed by DA reaction, gave a hard and stiff material, whereas curing above Tm gave a soft and stretchable one. When crystallization and crosslinking were promoted simultaneously, tough and ductile materials were obtained. Structural analysis of the network polymers showed that the variation in the properties was derived from the difference in the crystallinity, crystallite size, and network structure. Therefore, materials with various mechanical properties, from soft to hard, could be obtained by simple thermal treatment. (c) 2012 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2012