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

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• 作者：Zhen-Yu Zhang ; Qi-Kai Zhang ; Zhihao Shen ; Jian-Peng Yu ; Yi-Xian Wu ; Xing-He Fan
• 刊名：Macromolecules
• 出版年：2016
• 出版时间：January 26, 2016
• 年：2016
• 卷：49
• 期：2
• 页码：475-482
• 全文大小：488K
• ISSN：1520-5835

文摘

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 (T_g) 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 thermoplastic elastomer (LCTPE). The maximum elongation at break and the tensile strength of M-B-M-55 are 736% and 10.6 MPa, respectively, and the stretching strength at 300% is 6.9 MPa. Above the T_g of PMPCS, the LC phase of PMPCS provides new physical cross-linking points in the LCTPEs, and the triblock copolymer M-B-M-55 still shows a relatively high modulus.