Lignin-Modified Epoxy Resin With Good Mechanical and Shape Memory Performance Fabricated by Synergistic Dispersion and Crosslinking With Polyetheramine

To improve the reactivity and compatibility of lignin, it was first functionalized via the method of epoxidation. The epoxidized lignin (LEP) modified epoxy resin with good mechanical and shape memory performance was fabricated ingeniously by introducing the LEP into the epoxy resin homogeneously with the aid of synergistic dispersion and crosslinking of polyetheramine without using organic solvents. The effect of LEP addition on the curing reaction, thermal, mechanical, and shape memory performance of epoxy resin were intensively evaluated. The epoxy-diamine curing reaction was promoted by the LEP incorporation, and the thermal stability and mechanical performance of epoxy resin were improved. The tensile strength and modulus of the LEP-modified epoxy were increased by 14.3% and 32.5%, respectively. Such reinforcing effect of LEP on the thermal and mechanical performance was contributed to the rigid LEP chains which were chemically crosslinked into the network of epoxy resin uniformly. Also, the rigid LEP component in the cured epoxy resin inhibited the movement of chain segments, which could enhance the mechanical stability and slow down the rapid shape recovery rate of the epoxy resin network to some extent.