One-Pot Synthesis of Supertough, Sustainable Polyester Thermoplastic Elastomers Using Block-Like, Gradient Copolymer as Soft Midblock

Abstract

It remains challenging to synthesize supertough thermoplastic elastomers (TPEs) since the stretchability and tensile strength are mutually exclusive. Here, we report a one-pot strategy for the preparation of sustainable, triblock polyester TPEs consisting of poly(L-lactide) (PLLA) hard segments and poly(εcaprolactone)-co-poly(δ-valerolactone) (PCVL) soft segments. The TPEs were synthesized successfully with high stretchability (up to 2100%) and strong tensile strength (up to 71.5 MPa) without requiring specific functionalized groups by simply adjusting the polymer microstructures, which, in turn, exhibited a world's record toughness of 445 MJ/m3. Systematic investigation revealed that the block-like, gradient microstructure of PCVL improved the ductility by providing a flexible elastic network and enhancing the tensile strength through strain-induced crystallization. The practicability of this strategy was well demonstrated by lifting a water tank over 30,000 times heavier than itself and easy scale-up experiments.