4D Printing of Ultra-High Performance Shape Memory Polymer for Space Applications

Abstract

Developing thermoplastic polyimide (TPI), capable of handling space conditions, through 4D printing is challenging due to its high melting temperature and inherent viscosity. This study presents 4D printing of TPI for shape memory investigation under repetitive cycles for the first time, exploring its potential for self-deployable hinges in space devices. 4D-printed TPI exhibits outstanding shape memory effect (SME) with shape fixity (R_f) up to 100% and shape recovery (R_r) of 100% in first cycle. R_f is noted to be increasing up to third cycle and then fixed to 100% up to tenth cycle, while R_r shows a decreasing trend in subsequent cycle with a drop of 37% in tenth cycle. Moreover, it exhibits extremely high glass-transition temperature, T_g = 263.10 °C, degradation temperature, T_d = 520 °C, and storage modulus of 1600 MPa. Among existing high-performance (HP) and conventional shape memory polymers (SMPs), 3D-printed TPI exhibits superior performance. T_g of the TPI is found to be 66.52%, 107.16%, and 62.41%, higher than existing HP-SMPs, polyether ether ketone (T_g = 158 °C), polyamide (T_g = 127 °C), and polyether ketone ketone (T_g = 162 °C), respectively. This investigation reveals a novel characteristic, the SME, of 4D-printed TPI with ultra-high T_g and T_d, demonstrating suitability for self-deployable hinges, contributing to materials engineering and 4D printing.