A self-healing transparent polydimethylsiloxane elastomer based on imine bonds

Smart materials with self-healing properties that can heal themselves with restored mechanical performance are highly desired. Herein, a transparent healable PDMS (HPDMS) elastomer based on imine bonds is successfully prepared from amino-modified polydimethylsiloxane (PDMS) and 1,4-diformylbenzene (DFB) through a simple method. The concentration of DFB has a great effect on the gelation process. The elastomer features an outstanding optical transmittance (more than 80%) over the full visible light region. The results of TGA and DSC indicate that the HPDMS elastomer is highly flexible at room temperature and can be used in a wide temperature range. The presence of imine bonding and the formation of Schiff base linkages is proved by the FT-IR and Raman spectra. The reversible imine bond can promote the contact of the fracture surfaces and result in quick and repeatable self-healing without any external intervention such as heat or light. Furthermore, the elastomer exhibits excellent recyclability and reprocessability. Besides, the adhesion test reveals the potential of the elastomer in application as adhesives. We anticipate that this strategy can be employed to prepare a transparent PDMS elastomer with mechanical strength, stretchable, and excellent self-healing properties.