Shape memory ethylene copolymer/graphene nanocomposites network containing thermoreversible Diels-Alder couplings

Abstract

Recyclable SMPs were prepared by chemical crosslinking of glycidyl containing ethylene copolymer (G-PE) with end-carboxylated Diels-Alder (DA) adduct derived from furan carboxylic acid and bismaleimide. FT-IR and solubility test showed that these G-PE/DA networks are successfully formed via the reaction of glycidyl group of G-PE with carboxylic acid of DA adduct. The thermoreversibility of the networks was proven with DSC measurement and solubility test. The tensile test showed that the reprocessed samples exhibited almost the same mechanical properties as original sample. The G-PE/DA network exhibited an excellent thermally triggered shape memory effect when the temporarily fixed shape was heated above their crystalline melting temperature. It also showed surface crack healing property, which was confirmed by SEM and tensile test. Octadecylamine functionalized reduced graphene oxide (f-rGO) was incorporated into the G-PE/DA network by a melt blending process. FE-SEM analysis revealed that f-rGOs were dispersed uniformly in the nanocomposites. Tensile test showed that the nanocomposites exhibited a greatly enhanced mechanical properties compared to the G-PE/DA network. The graphene-based nanocomposites exhibited faster thermally-triggered shape recovery rate compared to the unfilled network. In addition, the nanocomposites showed shape memory effects under NIR irradiation.