Synthesis and Characterization of New Liquid Crystalline Thermoplastic Elastomers Containing Mesogen-Jacketed Liquid Crystalline Polymers

In order to improve the high-temperature performance of thermoplastic elastomers (TPEs), we designed and synthesized a new kind of ABA triblock copolymer containing a mesogen-jacketed liquid crystalline polymer (MJLCP), poly{2,5-bis[(4-methoxyphenyl)oxycarbonyl]styrene} (PMPCS), as the hard blocks and polybutadiene (PB) as the soft block. The triblock copolymer, PMPCS-b-PB-b-PMPCS (M-B-M), was synthesized by ring-opening metathesis polymerization in the presence of a chain transfer agent and atom transfer radical polymerization. The glass transition temperature (Tg) of the PMPCS hard block is 110–118 °C in the triblock copolymers. In addition, the liquid crystalline (LC) phase of PMPCS is stable before thermal decomposition. All the triblock copolymers form lamellar microphase-separated structures, as demonstrated by small-angle X-ray scattering and transmission electron microscopy results. The triblock copolymer (M-B-M-55) with a mass fraction of 55% of PMPCS exhibits typical properties of an LC thermopl...