Fabrication and Characterization of Multistimuli‐Responsive Shape Memory Polystyrene‐B‐Poly(Ethylene‐Ran‐Butylene)‐B‐Polystyrene/Polycaprolactone and Graphene Composites

Graphene, known for its exceptional electrical conductivity and mechanical strength, is widely used as a carbon‐based filler in the development of functional polymer composites. Its incorporation into shape memory polymers (SMPs) enables the fabrication of electro‐ and photo‐responsive smart composites. In this study, thermally responsive SMP composites are prepared using polystyrene‐b‐poly(ethylene‐ran‐butylene)‐b‐polystyrene (SEBS) and poly(ε‐caprolactone) (PCL) as the matrix, with varying graphene loadings. The influence of graphene content on the thermal, mechanical, and shape memory properties of the composites is systematically investigated. Differential scanning calorimetry analysis reveal that graphene acted as a nucleating agent for the PCL phase, increasing the crystallization temperature and degree of crystallinity. Increasing graphene content leads to improvements in storage modulus, elastic modulus, and creep resistance. However, the thermally‐induced shape memory performance decrease inversely with graphene content. The composite containing 30 phr graphene exhibits a volume electrical resistivity of 834.1 Ω·cm and achieve 95.12% electroactive shape recovery under 48 V within 180 s. Moreover, lower graphene loadings enhance photothermal conversion efficiency under 808 nm near‐infrared light. The composite with 5 phr graphene achieves 100% light‐triggered shape recovery within 45 s under 116 mW cm − 2 irradiation.