Bibenzoic acids

Polybibenzoates are a kind of thermotropic polyesters obtained by polycondensation of 4,4 -biphenyldicar-boxylic acid (p,p -bibenzoic acid) with a diol. These polyesters contain the biphenyl group, which is one of the simplest mesogens. They are synthesized by melt transesterification of the dimethyl or diethyl ester of p,p -bibenzoic acid and the corresponding diol, using a titanium compound as catalyst, according to the following scheme ... 

The isomeric bibenzoic acids (BBs), would appear to share similar structural features with naphthalene dicarboxylic acid. Like the PET-naphthalate copolymers, PET-bibenzoates have been demonstrated to possess moduli and glass transitions temperatures which increase with increasing levels of rigid comonomer [37-39], Unlike the PET/PEN copolymers, when the symmetrical 4,4 - I f I f monomer is substituted into a PET backbone, virtually every composition of PET-BB is semicrystalline the 2,4- and 3,4- isomers of BB, when... 

Table 6.1 Thermal properties of PET copolymers containing 10mol% of various x, 4/-bibenzoic acids as comonomers...

Minor Differences. Another point of difference between British and American custom is the use of di in diphenyl (Britain) and of bi in biphenyl (U.S.A.). The British do not use double-molecule names such as bibenzoic acid (dicarboxy-diphenyl), because it is only the radical which is doubled. There is also the question of the state of reduction of cyclic ketones. The British define the state of reduction in the name of the compound, whereas American practice allows it to be taken for granted whenever possible. 

Diphenic Acid. [1,1 -Biphenvl]-2,2 -dicarboxylic acid o,o -bibenzoic acid. Cl4HM04 mol wt 242.22. C 69.42%, H 4.16%, O 26.42%. Prepd from diazotized anthra-nilie add by treatment with a cuproammonia-sulfite reducing agent Vorlander, Meyer, Ann, 320, 122 (1902) Atkinson, Lawler. Org.. Svn coll, vol. 1 (2nd ed, 1941) p 222. By chromic acid oxidation of pheuanthrenequinone Roberts,... 

Transitions with the participation of liquid crystals may show characteristic phenomena. In this connection, for polyester of p,p bibenzoic acid with hexamethylene diol, smectic liquid comes from the isotropic one in the form of batoggetggwhich coalesce and grow into a focal-conic texture (Fig. 12) . Such observations... 

Fig. 12. Smectic batonnets observed at 229°C for a homopolyester of p,p -bibenzoic acid with hexamethylene glycol. Crossed polarizers.

Bromohyd roquinone-co4,4 -(decamethy lenedioxy) bibenzoic acid (Decamethylenedioxy)-bibenzoic acid-co-4,4 -(ethylenedioxy) diphenol Single Tgi microscopy Transition temperature from a mesof ase to an isotopic phase changed continuously and smoothly depending on the composition Jin et al, (1986)... 

B 120 Bibenzoic acid, other isomers. See Biphenyldicarboxylic acid. 

Copolymer of bromohydro-quinone and 4,4 -(decame-thylenedioxy) bibenzoic acid... 

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