Thermomechanical analysis of a novel directionally reinforced shape-memory polymer for minimally invasive surgical devices

Shape memory polymers (SMP's) are a class of materials that can undergo significant deformation and recover to an original shape upon exposure to a pre-programmed stimulus. One class of thermally activated SMP's provide an ideal candidate for use minimally invasive surgical devices since they can be activated when heated to body temperature. In this investigation the previously characterized tert-Butyl acrylate (tBA), Poly(ethylene glycol) dimethacrylate (PEGDMA) network was reinforced with medical fabric to increase the tailorability and enhance the mechanical properties of the system.;Three polyethylene terephthalate (PET) meshes with varying mechanical properties were used to reinforce the SMP network. They effectively allowed the elastic modulus of the network to be increased without altering the amount of crosslinking. This created new composite materials that maintained strain to failure while increasing their modulus. The glass transition temperature (Tg) and shape memory effect of all composite materials was maintained at the preprogrammed values.;Stents were fabricated and deployed at body temperature in unconstrained conditions. The 20% crosslinked systems showed no signicant difference between recovery in the pure SMP system and the PET composite system. However, the 40% crosslinked composite displayed increased recovery time compare to the pure 40% SMP network.