Novel thermoplastic elastomers based on multiblock copolymers of poly(L-lysine) (PLL), poly(N-epsilon-carbobenzyloxyl-L-lysine) (PZLL), poly(epsilon-caprolactone) (PCL), and poly(ethylene glycol) (PEG) were synthesized by combination of ringopening polymerization (ROP) and chain extension via L-lysine diisocyanate (LDI). SEC and H-1 NMR were used to characterize the multi-block copolymers, with number-average molecular weights between 38,900 and 73,400 g/mol. Multi-block copolymers were proved to be good thermoplastic elastomers with Young's modulus between 5 and 60 MPa and tensile strain up to 1300%. The PLL-containing multi-block copolymers were electrospun into non-woven mats that exhibited high surface hydrophilicity and wettability. The polypeptide-polyester materials were biocompatible, bio-based and environment-friendly for promising wide applications. (C) 2016 Wiley Periodicals, Inc.