Preparation of Azophenyl Photo-Induced Phase Transition Polymer and its Study on Adhesion Property

The design and synthesis of photo-induced reversible adhesives are considered to be the solution to the problems of traditional adhesives in separating, recycling, and repairing. We have designed and synthesized an azophenyl copolymer (PNY-Azo) with photo-induced phase change properties. The adhesion strength of PNY-Azo varies greatly between trans conformation (solid-state) and cis conformation (liquid state), which is suitable for photo-induced reversible adhesives application due to the reversible photo-induced bonding/debonding process between two substrates. By increasing the number of oxygen atoms on the side chains of the copolymer, the supramolecular interaction (H bond) between the copolymer molecular chains and the entanglement of copolymer chains are improved, which can be enhanced the adhesion strength (up to 4.59 MPa) of trans conformation PNY-Azo effectively.