Nanocomposites of Poly(n-Butyl Acrylate) with Fe₃O₄: Crosslinking with Hindered Urea Bonds, Reprocessing and Related...

In this contribution, we reported the synthesis of the nanocomposites of poly(n-butyl acrylate) with Fe₃O₄ nanoparticles (NPs) via dynamic crosslinking of poly(n-butyl acrylate)-grafted Fe₃O₄ NPs with hindered urea bonds (HUBs). Towards this end, the surfaces of Fe₃O₄ NPs were grafted with poly(n-butyl acrylate-ran-2-(3-tert-butyl-3-ethylureido)ethyl acrylate) chains [denoted as Fe₃O₄-g-P(BA-r-TBEA)] via living radical polymerization. Thereafter, 1,2-bis(tert-butyl)ethylenediamine was used as a crosslinker to afford the organic-inorganic networks with variable contents of Fe₃O₄ NPs and crosslinking densities. It was found that the fine dispersion of Fe₃O₄ NPs in the matrix of poly(n-butyl acrylate) was achieved. The nanocomposites exhibited excellent reprocessing properties, attributed to the introduction of HUBs. Owing to the crosslinking, the nanocomposites displayed excellent shape memory properties. Further, the nanocomposites possessed photo- and magnetic-thermal properties, which were inherited from Fe₃O₄ NPs. These functional properties allow triggering the shape shifting of the nanocomposites in an uncontacted fashion.