Review of Progress in Shape Memory Epoxies and Their Composites

Shape memory polymer (SMP) is capable of memorizing one or more temporary shapes and recovering successively to the permanent shape upon various external stimuli. Beside of the above mentioned one-way variants, also two-way shape memory polymers (SMPs) and shape memory (SM) systems exist which feature a reversible shape change on the basis of “on-off switching” of the external stimulus. The preparation, properties and modelling of shape memory epoxy resins (SMEP), SMEP foams and composites have been surveyed in this exhaustive review article. The underlying mechanisms and characteristics of SM were introduced. Emphasis was put to show new strategies on how to tailor the network architecture and morphology of EPs to improve their SM performance. To produce SMEPs novel preparation techniques, such as electrospinning, ink printing, solid-state foaming, were tried. The potential of SMEPs and related systems as multifunctional materials has been underlined. Added functionality may include, among others, self-healing, sensing, actuation, porosity control, recycling. Recent developments in the modelling of SMEPs were also highlighted. Based on the recent developments some open topics were deduced which are merit of investigations in future works

Tensile and Fracture Mechanical Properties of Styrene-Butadiene Rubbers (SBR) Filled with Industrial and Pyrolytic Carbon Blacks, and Organoclay

In this work we examined effects of filler combinations (industrial carbon black (CB), pelletized pyrolytic carbon black (pCBp) and organoclay (I30.P) on the tensile mechanical and fracture mechanical properties of SBR rubbers. The performance of standard N660 CB was compared with that of pCBp when used alone or in 1: 1 blend ratio at an overall filler content of 60 part per hundred part rubber (phr). The study covered also a mix composed of 20 phr pCB, 20 phr N660 and 10 phr I30.P the hardness of which was identical to those of the (p)CB filled ones. N660 yielded better tensile properties than pCBp. By contrast, the latter yielded higher tear and trouser tear strength values than CB. I30.P increased the storage modulus value (E’) in spite of the filler content of 50 phr. Presence of organoclay and pCBp also increased the critical value of the J-integral.</jats:p