Combined Main-Chain/Side-Chain Liquid Crystalline Polymer with   Main-Chain On the basis of &quot;Jacketing&quot; Effect and Side-Chain Containing   Azobenzene Groups

doi:10.1021/ma200851v

CORC > 北京大学 > 化学与分子工程学院

	Combined Main-Chain/Side-Chain Liquid Crystalline Polymer with Main-Chain On the basis of "Jacketing" Effect and Side-Chain Containing Azobenzene Groups
	Xie, He-Lou ; Wang, Shao-Jie ; Zhong, Guan-Qun ; Liu, Yi-Xin ; Zhang, Hai-Liang ; Chen, Er-Qiang
刊名	macromolecules
	2011
关键词	OPENING METATHESIS POLYMERIZATION TRANSFER RADICAL POLYMERIZATION PHASE STRUCTURES THERMOTROPIC POLYPEPTIDES DIBLOCK COPOLYMERS MOLECULAR PACKING MESOGENIC GROUPS BEHAVIOR DESIGN TRANSITIONS
DOI	10.1021/ma200851v
英文摘要	Combining the concept of "flexible spacer" which can bring liquid crystalline (LC) properties to the side-chains and the side-group "jacketing" effect which can result in main-chain with rod-like conformation, we have synthesized a new combined main-chain/side-chain LC polymer based on radical polymerization, poly (2,5-bis{[6-(4-methoxy-4'-oxy-azobenzene)hexyl]oxycarbonyl}styrene) (denoted as P(1)) with two azobenzene groups per repeating unit. The chemical structures of P(1) and the corresponding monomer were characterized using various techniques with satisfactory analysis data. The phase structures and transitions of P(1) were investigated using differential scanning calorimetry, polarized optical microscope, and one- and two-dimensional (1D and 2D) wide-angle X-ray diffraction. We identify that P(1) can form a hierarchically ordered structure with double orderings on both the nanometer and subnanometer length scales. Most likely, the thick main-chains of Pi obtained by "jacketing" the central rigid portion of terephthalate side-chain to the polyethylene backbone construct a 2D centered rectangular scaffold, which is stable until the sample becomes completely isotropic. The packing of side-chains inside the main-chain scaffold undergoes the transitions of smectic B- (SmB-) like <-> smecitc A (SmA)-like <-> isotropic. The confinement arising from the scaffold induces the SmB-like packing and enhances the stability of SmA-like structure. The hierarchically ordered structure of Pi renders a biaxial orientation with the side-chains perpendicular to the main-chains. We compared P(1) with an end-on side-chain LC polymer of poly(4-{[6-(4-methoxy-4'-oxy-azobenzene)hexyl]oxycarbonyl}styrene) (denoted as P(2)). P(2) bearing one mesogenic group per repeating unit forms a monolayer SmA phase, with the transition temperature much lower than that of P(1). Upon UV irradiation, in contrast to that P(2) will become isotropic, P(1) can still exhibit LC behavior after the azobenzene groups adopt cis conformation.; Polymer Science; SCI(E); EI; 0; ARTICLE; 19; 7600-7609; 44
语种	英语
内容类型	期刊论文
源URL	[http://ir.pku.edu.cn/handle/20.500.11897/313129]
专题	化学与分子工程学院
推荐引用方式 GB/T 7714	Xie, He-Lou,Wang, Shao-Jie,Zhong, Guan-Qun,et al. Combined Main-Chain/Side-Chain Liquid Crystalline Polymer with Main-Chain On the basis of "Jacketing" Effect and Side-Chain Containing Azobenzene Groups[J]. macromolecules,2011.
APA	Xie, He-Lou,Wang, Shao-Jie,Zhong, Guan-Qun,Liu, Yi-Xin,Zhang, Hai-Liang,&Chen, Er-Qiang.(2011).Combined Main-Chain/Side-Chain Liquid Crystalline Polymer with Main-Chain On the basis of "Jacketing" Effect and Side-Chain Containing Azobenzene Groups.macromolecules.
MLA	Xie, He-Lou,et al."Combined Main-Chain/Side-Chain Liquid Crystalline Polymer with Main-Chain On the basis of "Jacketing" Effect and Side-Chain Containing Azobenzene Groups".macromolecules (2011).