Design of ultrastretchable and super-elastic tailorable hydrophilic thermoplastic elastomeric materials

Abstract

In this work, new ultrastretchable and super-elastic hydrophilic thermoplastic elastomeric (TPEs) materials were developed for the first time from the thermoplastic polyurethane (TPU) and epichlorohydrin-ethylene oxide-allyl glycidyl ether (GECO) rubber using straightforward melt-blending and dynamic vulcanization approaches, which allows the creation of tailorable hydrophilic TPE materials. The resulting materials can absorb up to ∼80% water within 4 h. The absorbed water convert itself into hexagonal ice crystals in the TPE matrix which was directly evident from differential scanning calorimetry and cryo-transmittance electron microscopy. The phase components of developed TPE were found to be interactive which was analysed from the torque and loss tangent values. Interaction was further enhanced after dynamic vulcanization which was predicted from the rheological Palierne model. Interestingly, interfacial tension between the TPU and GECO was significantly reduced after dynamic vulcanization which suggested stronger inter-domain interaction between the phase components. It was revealed that the resulting TPE possess droplet-matrix phase morphological structure which was supported from the theoretical Kerner model prediction. Surprisingly, resulting materials showed extraordinary elastomeric properties than that of TPEs reported earlier, such as very high strain at break (∼800–1000%) and lowest tension set (∼2–6%) which enables the creation of ultrastretchable and super-elastic materials. • A new kind of ultra-stretchable, superelastic and tailorable hydrophilic TPE was developed. • The developed TPE showed extraordinary elastic properties having high strain at failure (1000%) and low-tension set (∼2%). • The hexagonal ice crystals were formed in the TPE matrix by absorbed water.