Synthesis and properties of a new high-temperature liquid crystalline thermoplastic elastomer based on mesogen-jacketed liquid crystalline polymer

In order to obtain high-temperature resistant thermoplastic elastomers (TPEs), we designed and synthesized a new kind of ABA triblock copolymer containing a mesogen-jacketed liquid crystalline polymer, poly(4'-(methoxy)-2-vinylbiphenyl-4-methyl ether) (PMVBP), as the hard blocks and polybutadiene (PB) as the soft block. PB was synthesized by ring-opening metathesis polymerization in the presence of a chain transfer agent, and PMVBP was synthesized by nitroxide-mediated radical polymerization. The glass transition temperature of the PMVBP block is 186-211 degrees C, which is much higher than that of polystyrene. More importantly, PMVBP can maintain its liquid crystallinity even when the temperature is as high as 270 degrees C, which can enhance the mechanical properties of TPEs based on PMVBP, especially at high temperatures. All the resulting PMVBP-PB-PMVBP triblock copolymer samples form lamellar microphase-separated structures after combined treatment of solvent annealing and thermal annealing. They are good candidates for TPEs with a high operating temperature of more than 200 degrees C. (C) 2016 Published by Elsevier Ltd.