The photoinduced back-and-forth deformation behavior of poly(arylene ether)s containing bis-azobenzene groups in the main chain

Abstract

The research on the photoresponsive properties of azobenzene-containing poly(arylene ether)s has received much attention due to their excellent thermal stability. Recently, it has been found that poly(arylene ether)s containing azobenzene groups in the main chain could undergo self-recoverable photoinduced deformation behavior. However, there are few studies on the influencing factors of the photoinduced deformation behavior of poly(arylene ether)s containing azobenzene groups. In this paper, a novel series of poly(arylene ether)s containing various bis-azobenzene groups in the main chain were synthesized, and the influencing factors of their photoinduced deformation behavior were studied. The photoinduced deformation behavior of the polymers could be affected by the structures and the contents of bis-azobenzene groups. The photoinduced deformation rates of the poly(arylene ether)s containing bis-azobenzene groups decreased with the rigidity of the bis-azobenzene groups but increased with the content of the bis-azobenzene groups. The photoinduced deformation behavior of the cantilevers of the polymers also can be adjusted by the polarization direction of the excitation laser. When the polarization direction of the polarized laser was perpendicular to the long axis of the cantilevers, the cantilevers bent away from the excitation laser at first and then turned towards the excitation laser, and the bending angles decreased with the contents of bis-azobenzene. Such back-and-forth photoinduced deformation behavior has not been reported before and should be helpful for the design of polymers with complex photoinduced deformation behavior.