Development of cyanate ester-based glass fibre reinforced shape memory polymer composite for low earth orbit applications – a comprehensive durability study

With the development of advanced shape memory polymers (SMPs) in recent years, the possibility of using SMPs in low earth orbit (LEO) applications has become an upcoming research topic. A well-developed SMP and its composites can manufacture autonomous satellite components and structures such as hinges, release mechanisms, antennas, truss booms, and modular structures. One of the major challenges for polymers in the LEO environment is the extreme environment. Conditions like thermal cycles, atomic oxygen exposure, and high-energy radiation can affect the SMPs, lowering their service time in the intended application. This research work presents the development of bisphenol A cyanate ester (BACE)-based shape memory polymer composite (SMPC) by incorporating polyethylene glycol (PEG) as a shape memory effect modifier, and graphene nanoplatelets (GNP). Furthermore, the SMPC was developed to achieve excellent shape programming at ~170°C and recovery behaviour at ~130°C to accommodate the thermomechanical integrity at the highest LEO environmental temperature. The SMPC underwent multiple durability tests, including atomic oxygen (AO) exposure test, tensile tests, creep test, thermal vacuum aging, cryogenic aging and air permeability test. The AO exposure test was conducted for 48 hours for an equivalent time of 300 days at a 550 km LEO orbit. The GNP-filled SMPC showed additional protection against AO erosion without significantly dropping its shape memory and mechanical properties. The mechanical test after aging further solidified the mechanical integrity of the SMPC to be used in extreme LEO conditions for a long service period. Interestingly, the creep test showed an advantageous behaviour of SMPC by keeping the constant load-induced strain stable at 130°C without failing. It can be concluded that the developed SMPC material has shown suitable properties for use in many LEO applications, including applications with long service life.