10.1039/c2jm32489j
The research primarily focuses on the synthesis and evaluation of a high-birefringence polymethacrylate with a diphenyl-diacetylene (DPDA) moiety in the side chain. The polymer was designed to form a nematic liquid crystal (LC) phase with a wide temperature range and exhibit high birefringence, which is crucial for applications in optical devices such as flat panel displays, optical fibers, and photostorage devices. The synthesis involved Negishi cross-coupling of an asymmetric diacetylene protected with a tert-butyldimethylsilyl (TBDMS) group and 2,2-dibromoalkene, followed by E2 reaction and deprotection with tetra-n-butylammonium fluoride (TBAF), and esterification with methacrylate chloride. Anion polymerization using n-butyllithium (n-BuLi) was employed to obtain the final polymer. The thermal properties were analyzed using differential scanning calorimetry (DSC) and polarizing optical microscopy (POM), while the optical properties, specifically the birefringence, were determined through UV-visible spectroscopy and a microscope spectroscopic method with a Nikon LV100 Pol optical microscope and a USB4000 spectrometer. The polymer showed a high birefringence of 0.3 at 550 nm at room temperature, indicating its potential for use in optical applications.
