Journal of Polymer Science Part A: Polymer Chemistry, Vol.37, No.11, 1703-1707, 1999
Synthesis of thermotropic LCPs using p-methoxycarbonyloxy aromatic acids
4-Methoxycarbonyloxybenzoic acid (MCOBA) and 6-methoxycarbonyloxy-2-naphthoic acid (MCONA) were synthesized as new monomers to replace 4-acetoxy-benzoic acid (ABA) and 6-acetoxy-2-naphthoic acid (ANA) in the synthesis of Liquid crystal polymers. MCOBA and MCONA (73 : 27, mel: mel) were reacted at temperatures ranging from 220 to 325 degrees C in bulk. The copolymer (M-w = 14,200) has a T-g (90 degrees C) and a T-m (249 degrees C). The MCOBA/MCONA copolymer is lighter in color than the ABA/ANA copolymer. During the copolymerization, six by-products were collected, isolated, and analyzed, and their formation was investigated. The copolymerization rate was studied by the measurement of evolved carbon dioxide. The polymerization of MCOBA and MCONA is cleaner and faster than the polymerization of ABA and ANA.