Abstract
In this study, Polyurea/Formaldehyde (PUF) microcapsules containing Dicyclopentadiene (DCPD) as a healing substance were fabricated in situ and mixed at relatively low concentrations (<2 wt%) with a thermosetting polyurethane (PU) foam used in turn as the core of a sandwich structure. The shape memory (SM) effect depended on the combination of the behavior of the PU foam core and the shape memory polymer composite (SMPC) laminate skins. SMPC laminates were manufactured by moulding commercial carbon fiber-reinforced (CFR) prepregs with a SM polymer interlayer. At first, PU foam samples, with and without microcapsules, were mechanically tested. After, PU foam was inserted into the SMPC sandwich structure. Damage tests were carried out by compression and bending to deform and break the PU foam cells, and then assess the structure self-healing (SH) and recovery capabilities. Both SM and SH responses were rapid and thermally activated (120 °C). The CFR-SMPC skins and the PU foam core enable the sandwich to exhibit excellent SM properties with a shape recovery ratio up to 99% (initial configuration recovery). Moreover, the integration of microcapsules (0.5 wt%) enables SH functionality with a structural restoration up to 98%. This simple process makes this sandwich structure ideal for different industrial applications.
Highlights
Li and Xu and Li et al suggested a SM polymers (SMPs) syntactic foam sealant for a compression-sealed expansion joint in a bridge floor or concrete roadway [29,30]. The integration of these SMP-based syntactic foams as cores of sandwich structures was formulated by Behl et al, who proposed the external confinement of fiber-reinforced polymer skins as an out-of-plane constraint to the SMP core [31]
The current study introduces design, manufacturing, as well as the self-healing ability of a shape memory composite sandwich structure composed of two shape memory polymer composite (SMPC) laminates as skins and a SM polyurethane foam with embedded PUF/DCPD microcapsules as core
Density compression tests were performed on cylindrical samplesand of the with
Summary
The distinctive aspect of shape recovery is the possibility of returning spatially to the original shape. This could aim and contribute to the external shape recovery of a structure, for example, after a damage. The self-healing effect refers to the ability of the material to be repaired automatically or by external stimuli after being damaged or cracked [9,10]. In this light, the addition of self-healing functionality through the addition of suitable SH materials is essential to complete the repairing action. The SH performance is mainly achieved in two ways: with either intrinsic or extrinsic methods
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
