Effects of graphene nanoplatelets on bio-based shape memory polymers from benzoxazine/epoxy copolymers actuated by near-infrared light

Novel near-infrared (NIR) light-induced bio-based shape memory polymers (SMPs) were prepared from copolymers of vanillin/furfurylamine-based benzoxazine monomer (V-fa monomer) and epoxidized castor oil (ECO). Incorporation of graphene nanoplatelets (GNPs) as photothermal fillers into the copolymers provided shape memory properties under near-infrared (NIR) light actuation. The effects of GNP content on photothermal, thermal, dynamic mechanical, morphology, and shape memory properties of the bio-based benzoxazine/epoxy copolymers (V-fa/ECO copolymers) were investigated. The results showed that the addition of GNPs significantly improved the photothermal, thermal, and dynamic mechanical properties of the copolymers. The uniform dispersion of 3 wt% GNPs in the V-fa/ECO copolymers resulted in the highest shape memory performance with shape fixity of 92% and shape recovery of 99% upon NIR light actuation. The recovery time decreased with the increment of GNP content, and the V-fa/ECO copolymers filled with GNPs displayed good execution in the repeated fold-deploy, in which the shape fixity and shape recovery values were close to the original specimen. Therefore, the outstanding properties of V-fa/ECO copolymers filled with GNPs had a potential to be excellent SMPs under NIR actuation.

Automated summary

Incorporation of graphene nanoplatelets as photothermal fillers significantly improved the photothermal, thermal, and dynamic mechanical properties of the bio-based benzoxazine/epoxy copolymers. The addition of 3 wt% GNPs resulted in the highest shape memory performance with shape fixity of 92% and shape recovery of 99%, demonstrating excellent shape memory properties. Additionally, the V-fa/ECO copolymers filled with GNPs showed good execution in repeated fold-deploy tests, with shape fixity and shape recovery values close to the original specimen.