Synthesis of novel multi-arm star azobenzene side-chain liquid crystalline copolymers with a hyperbranched core |
| |
Authors: | Xiaohua He Yiyong Mai |
| |
Affiliation: | College of Chemistry and Chemical Engineering, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai 200240, China |
| |
Abstract: | 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 1H 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 nematic 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 × 104 to 9.07 × 104. |
| |
Keywords: | Liquid crystalline polymer Atom transfer radical polymerization Hyperbranched polymer Copolymer |
本文献已被 ScienceDirect 等数据库收录! |
|