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.
| Original language | English |
|---|---|
| Pages (from-to) | 1759-1765 |
| Number of pages | 7 |
| Journal | European Polymer Journal |
| Volume | 40 |
| Issue number | 8 |
| DOIs | |
| State | Published - Aug 2004 |
| Externally published | Yes |
Keywords
- Atom transfer radical polymerization
- Copolymer
- Hyperbranched polymer
- Liquid crystalline polymer