Photo-crosslinkable and ultrastable poly(1,4-butadiene) based organogel with record-high reversible elongation upon cooling and contraction upon heating

Abstract

Two-way shape memory polymers with reversible elongation upon cooling (EUC) and contraction upon heating (CUH) have emerged as promising smart materials for use in soft actuators. However, it remains challenging to develop organogels with as high as possible actuation strain. Here, novel photo-crosslinkable poly(1,4-butadiene) (PBD) based organogels with exceptional stability and high reversible EUC and CUH have been developed for the first time. The conventional photo-initiator 2-hydroxy-2-methylpropiophenone and plasticizer bis(2-ethylhexyl) phthalate were utilized to achieve photo-crosslinking ability and to serve as the organic free phase, respectively. Owing to the stability of the plasticizer, the PBD based organogels are pretty stable in high vacuum environment and below 100 °C. Importantly, the PBD organogel with 60 wt % plasticizer exhibited the best overall performance, especially with the record-high EUC (156%) and CUH (151%), and the pretty high actuation reversibility (97%). Moreover, the high stretchability makes the PBD based organogels possess great potential in strain sensing application. The widely accessible raw materials and simple preparation method make PBD based organogels with good possibility in practical applications.