POSS-enhanced shape-memory copolymer of polynorbornene derivate and polycyclooctene through ring-opening metathesis polymerization

A copolymer consisting of polycyclooctene (PCOE) and poly(5-norbornene-exo, exo-2,3-dicarboxylic anhydride) (PNBEDCA) was firstly synthesized through ring-opening metathesis polymerization, and then the obtained copolymer P(COE-co-NBEDCA) was readily modified by grafting reaction of NBEDCA units with polyhedral oligomeric silsesquioxanes (POSS) to afford a novel functionalized copolymer P(COE-co-NBEDCA-g-POSS), in which carboxyl and POSS as side chains attached to polynorbornene backbones. The copolymers were characterized by means of thermogravimetry, wide-angle X-ray diffraction, and stress-strain measurements. The shape memory effect of the copolymer was evaluated by dynamical mechanical analysis and shape recovery speed. Having the properties of the good shape fixity and the large shape recovery, the POSS-enhanced copolymer is expected to use as a potential shape memory material.