Bending shape recovery of unidirectional carbon fiber reinforced epoxy-based shape memory polymer composites

Thermosetting Shape Memory Polymers and Composites Based on Polybenzoxazine Blends, Alloys and Copolymers

“…The maximum recovery stresses increase almost proportionally to the fiber mass contents in the range of 16.5 MPa to 49.0 MPa during reheating. The composites featured good shape memory properties during cyclic loading and unloading at 120 °C . During the second cycle of free recovery experiments as well as the constrained displacement recovery test, respectively the maximum flexural stress during deformation process and maximum recovery stress showed a decline in stress values compared to the appropriate ones of the first cycles.…”

“…F. Li et al. have studied systematically the SMPC performance in three‐point bending test with 5 % strain of deformation of unidirectional carbon fiber reinforced epoxy‐based SMPC with fiber mass fractions of 16 %, 23 %, 30 %, and 37 % aiming at a mechanical characterization for direct engineering application . The composites show good shape recovery performance, with measured recovery ratios of more than 93 % reaching 120 °C and almost 100 % after holding the specimen at 120 °C.…”

“…The composites featured good shape memory properties during cyclic loading and unloading at 120 8C. [52] During the second cycleo f free recovery experimentsa sw ell as the constrained displacement recovery test, respectively the maximum flexurals tress during deformationp rocess and maximum recoverys tress showedad ecline in stress values comparedt ot he appropriate ones of the first cycles. The authors assume internal damages probablyb ased on microcracks resulting from manufacturing and deformation processes as ar easonf or the energy dissipation.…”

Future Prospects: Shape Memory Features in Shape Memory Polymers and Their Corresponding Composites

“…Therefore, as the temperatures increased, the chain segments will have enough energy to release and thus perform the shape recovery. Figure 21a and b displays the epoxy-based SMPs reinforced of carbon fibers with four percentages ratio of 16, 23, 30, and 37% were designed by Li et al [63]. The designed composites have demonstrated an excellent shape recovery at 120°C within a ratio of 90% and obtained a full recovery 100% after 20 min at the same temperature.…”

“…(a) Stress recovery curves for four percentages of fiber reinforcement; (b) recovery ratio of the reinforced SMP composites with 23 and 37% mass fraction within different partial loads[63].19…”