Microwave-Triggered Thermo-Responsive Shape Memory Polymer (Polyurethane)/GNPS/MWCNTS Composites

The work reported herein, analysis of microwave irradiations triggered thermo-responsive shape memory polyurethane (PU)/Graphene nanoplatelets (GNPs)/Multiwalled Carbone nanotubes (MWCNTs) nanocomposites were prepared through ex-situ polymerization technique by using a micro-compounder. Atomic force microscopy (AFM) and field emission scanning electron microscopy (FE-SEM) were used for surface morphology characterization. Shape memory and mechanical properties both were superior for 1 GPU as compared to 1 CNTPU followed by pure polyurethane (PU). Pure PU sample has no shape recovery under microwave irradiations, whereas composites exhibit shape recovery of almost 90% of their original shape within one minute recorded by the thermal imager. Maximum shape recovery under microwave irradiation was observed for 1 GPU composite. GNPs have strong absorption of microwave irradiation followed by MWCNTs, but pure PU has no absorption capacity, which may be the reason for the microwave irradiation-triggered shape recovery phenomenon. Further, the GNPs have higher thermal conduction, absorption of microwave irradiation, strength, and strain energy than MWCNTs. Glass transition temperature strongly influences the reinforcement of nanoparticles. Microwave-triggered shape memory polymer may open the new research gate for non-contact heating, clean green sources, as well as wireless and remote sensing applications.