Abstract
Hydroxyl-terminated liquid crystalline bis[4-(5-hydroxypentyloxycarbonyl)phenylene] terephthalate (BHT) was prepared and compared with its non-hydroxylated analog, bis[4-(pentyloxycarbonyl)phenylene] terephthalate (BPT). BHT, with the possibility to form intermolecular hydrogen bonding (H-bonding), has higher thermal transition temperatures (T m and T i) than BPT. Infrared spectroscopy was applied to prove the existence of H-bonding for BHT. An X-ray diffraction study suggests that the smectic A (SA) phase is the only phase existing for BPT but for BHT, an interdigitated layered structure was found to be mixed with the SA phase. The formation of this interdigitated layered structure is mainly due to the intermolecular H-bonding between the terminal hydroxyl and the external ester groups in BHT.