Journal of Applied Polymer Science, Vol.59, No.6, 1001-1008, 1996
Synthesis and Characterization of Oligoethylene Bibenzoate with Hydroxyethyl End-Groups
In the process of exploring the potential advantage of 4,4’-biphenyl dicarboxylic acid (BDA) as a comonomer in poly(ethylene terephthalate) (PET), it was found that BDA needs to be derivatized for effective incorporation in PET specifically if high levels of BDA incorporation are desired. Bis-hydroxyethylbibenzoate (HEB) was synthesized with the anticipation that it would be compatible with both the continuous PET process which uses high-purity terephthalic acid as well as the batch PET process which utilizes dimethyl terephthalate. This article describes the synthesis of HEB and some of the oligoethylene bibenzoates produced in the process. Diethylene glycol is produced as an undesirable by-product during the reaction. In an effort to produce a minimum amount of diethylene glycol, a catalytic process was investigated which resulted in diethylene glycol levels of less than 0.5%. Quantitative analysis of diethylene glycol, performed by gas chromatography, and the oligomer structure studies performed by H-1- and C-13-NMR are described.
Keywords:THERMOTROPIC LIQUID-CRYSTALS;MESOGENIC P;P’-BIBENZOATE UNIT;SMECTIC MESOPHASE PROPERTIES;PARA;PARA’-BIBENZOIC ACID;POLYESTERS;GLYCOL;BEHAVIOR;PHASE