Microwave-Induced Poly(ionic liquid)/Poly(vinyl alcohol) Shape Memory Composites

Recently, different stimuli triggered shape memory polymer composites (SMPC) have received much research interest. However, most shape memory effects (SME) in polymer composites are mainly caused by introducing different functional inorganic fillers into polymer matrix. In the present work, the special structure of poly(ionic liquids), the heating effect of microwaves (MW), and the mechanism of SMPs are combined to design MW induced SMPC completely based on polymers, poly(ionic liquid)/poly(vinyl alcohol) (PIL/PVA) polymer networks. PILs contain anion cation pairs, which have strong MW absorption capability due to their dielectric properties. Polymer composites absorb MW energy under irradiation and generate MW heating, which could provide the required energy for shape recovery. The functional ionic liquid monomer (MIL) styrene imidazole ([VBBI][BF 4 ]) is synthesized and polymerized. Then, PIL is mixed into PVA solution, which is crosslinked with glutaraldehyde to form P[VBBI][BF 4 ]/PVA polymer networks. 1 H NMR is used to characterize the structure of the synthesized styrene imidazole ILM and PIL. A bending test is applied to quantitatively characterize SMEs, which are affected by the PIL content in the composites and the applied MW power output. The present work combines the advantages of microwaves with PILs, opening up an efficient and environmentally friendly field for SMPs.