Synthesis and characterization of liquid crystals and their thermoset films |
| |
Authors: | Yong-Ho Ahn Myung-Sup Jung Jin-Hae Chang |
| |
Affiliation: | 1. Department of Polymer Science and Engineering, Kumoh National Institute of Technology, Gumi 730-701, Republic of Korea;2. Advanced Materials Lab, Samsung Advanced Institute of Technology, Yongin 446-712, Republic of Korea |
| |
Abstract: | We prepared a series of aromatic liquid crystals (LCs) based on aromatic ester units with the reactive end groups methyl-maleimide and nadimide, and the resulting LCs were thermally cross-linked to produce liquid crystalline thermoset (LCT) films by means of solution-casting and heat treatment. The synthesized LCs and LCTs were characterized with Fourier transform infrared (FT-IR) spectroscopy, 1H nuclear magnetic resonance (NMR), differential scanning calorimetry (DSC), thermomechanical analysis (TMA), and polarizing optical microscopy with a hot stage. We found that all these LCs form nematic phases. The coefficients of thermal expansion (CTEs) of the LCT films are strongly affected by the reactive end group and the mesogen units in their main-chain structures. The methyl-maleimide-terminated biphenyl LCT was found to have the lowest CTE. |
| |
Keywords: | Liquid crystal Liquid crystalline thermoset Coefficients of thermal expansion Reactive end group |
本文献已被 ScienceDirect 等数据库收录! |
|