Synthesis of novel multi-arm star azobenzene side-chain liquid crystalline copolymers with a hyperbranched core

被引：35

作者：

He, XH ^{[1
]}

Yan, DY ^{[1
]}

Mai, YY ^{[1
]}

机构：

[1] Shanghai Jiao Tong Univ, Coll Chem & Chem Engn, Shanghai 200240, Peoples R China

来源：

EUROPEAN POLYMER JOURNAL | 2004年 / 40卷 / 08期

基金：

中国国家自然科学基金;

关键词：

liquid crystalline polymer; atom transfer radical polymerization; hyperbranched polymer; copolymer;

D O I：

10.1016/j.eurpolymj.2004.04.004

中图分类号：

O63 [高分子化学（高聚物）];

学科分类号：

070305 ; 080501 ; 081704 ;

摘要：

A series of novel multi-arm star side-chain liquid crystalline (LC) copolymers with hyperbranched core moieties were synthesized by atom transfer radical polymerization (ATRP) using a multi-functional hyperbranched polyether as the initiator and chlorobenzene as the solvent. The multi-functional hyperbranched polyether initiator was prepared from poly(3-ethyl-3-(hydroxymethyl)oxetane) (PEHO) and 2-bromo-2-methylpropionyl bromide. The azobenzene side-chain liquid crystalline arms were designed to have an LC conformation of poly[6-(4-methoxy-4'-oxy-azobenzene)hexyl methacrylate] with different molecular weights. Their characterization was performed with H-1 NMR, size exclusion chromatograph (SEC), differential scanning calorimetry (DSC) and thermal polarized optical microscopy (POM). The multi-arm star side-chain liquid crystalline copolymers exhibited a smectic and a nernatic phase, and the phase transition temperatures from the smectic to the nematic phase and from the nematic to isotropic phase increased with increasing the molecular weight of the multi-arm star side-chain liquid crystalline copolymers from 1.78 x 10(4) to 9.07 x 10(4). (C) 2004 Elsevier Ltd. All rights reserved.

引用

页码：1759 / 1765

页数：7

共 49 条

[1] Amphiphilic stars and dendrimer-like architectures based on poly(ethylene oxide) and polystyrene [J].

Angot, B ;

Taton, D ;

Gnanou, Y .

MACROMOLECULES, 2000, 33 (15) :5418-5426

[2]

Asthana S, 1999, J POLYM SCI POL CHEM, V37, P2235, DOI 10.1002/(SICI)1099-0518(19990701)37:13<2235::AID-POLA38>3.0.CO

[3]

2-V

[4] Star-shaped polymers by metal-catalyzed living radical polymerization. 1. Design of Ru(II)-based systems and divinyl linking agents [J].

Baek, KY ;

Kamigaito, M ;

Sawamoto, M .

MACROMOLECULES, 2001, 34 (02) :215-221

[5] Multihydroxyl branched polyethers. 2. Mechanistic aspects of cationic polymerization of 3-ethyl-3-(hydroxymethyl)oxetane [J].

Bednarek, M ;

Kubisa, P ;

Penczek, S .

MACROMOLECULES, 2001, 34 (15) :5112-5119

[6]

Bednarek M, 1999, MACROMOL RAPID COMM, V20, P369, DOI 10.1002/(SICI)1521-3927(19990701)20:7<369::AID-MARC369>3.0.CO

[7]

2-S

[8] A modular approach toward functionalized three-dimensional macromolecules:: From synthetic concepts to practical applications [J].

Bosman, AW ;

Vestberg, R ;

Heumann, A ;

Fréchet, JMJ ;

Hawker, CJ .

JOURNAL OF THE AMERICAN CHEMICAL SOCIETY, 2003, 125 (03) :715-728

[9] Atom transfer radical polymerization of methyl acrylate from a multifunctional initiator at ambient temperature [J].

Carlmark, A ;

Vestberg, R ;

Jonsson, EM .

POLYMER, 2002, 43 (15) :4237-4242

[10] Liquid crystalline rod-coil block copolymers by stable free radical polymerization: Synthesis, morphology, and rheology [J].

Gopalan, P ;

Zhang, YM ;

Li, XF ;

Wiesner, U ;

Ober, CK .

MACROMOLECULES, 2003, 36 (09) :3357-3364

← 1 2 3 4 5 →