Synthesis and Characterization of Novel Polyarylates from 2,5-Bis(4-hydroxyphenyl)-3,4-diphenylthiophene and Various Aromatic Dicarboxylic Acids

Abstract

ABSTRACT:A new tetraphenylated heterocyclic diol, 2,5-bis(4-hydroxyphenyl)-3,4-diphenylthiophene, was synthesized in three steps starting from 4-methoxydeoxybenzoin. The tetraphenylthiophene-containing polyarylates having inherent viscosities of 0.29--0.84 dig-1 were prepared by the high temperature solution polycondensation of the diol with various aromatic dicarboxylic acid chlorides. All the polyarylates were crystalline or semicrystalline, and the crystalline polyarylates were quite insoluble in organic solvents, while the others dissolved readily in a variety of solvents including N-methyl-2-pyrrolidone and sym-tetrachloroethane. These polymers had glass transition temperatures in the range of 209-260°C, with no weight loss below 400°C in both air and nitrogen atmospheres. KEY WORDSHigh Temperature Polyarylates / Tetraphenylthiophenediol / Solubility / Crystallinity / Thermal Behavior / Polyarylates have been known for their usefulness in meeting the high performance requirements for various applications. 1 • 2 We already reported that the introduction of pendant phenyl groups through tetraphenylthiophene, 3 tetraphenylfuran, 4 and tetraphenylpyrrole units 5 into polyarylate backbones afforded organic-soluble polymers with high glass transition temperatures. The incorporation of these tetraphenylated heterocylic moieties were also found to be highly effective to produce aromatic polyamides and polyimides with the above desirable properties. [6][7][8][9][10][11][12] 2, 5-bis( 4-hdroxyphenyl)-3 ,4-di pherw l thiophene, as an alternative monomer to the polyarylate-forming diacid, 2,5-bis( 4-carboxyphenyl)-3,4-diphenylthiophene. 3 This article deals with the synthesis of the tetraphenylthiophenediol as well as of new tetraphenylthiophene-containing polyarylates derived from various aromatic dicarboxylic acid chlorides. Their properties are also described, which are compared with those of the tetraphenylated heterocycle-containing polyarylates reported previously. 3 -5 As part of an effort to develop organicsoluble high performance polyarylates with high glass transition temperatures, we have aimed at the synthesis of a new tetraphenylthiophene-containing diol monomer,

Design and Synthesis of Aromatic Polyesters Bearing Pendant Clickable Maleimide Groups

“…The widely used polymerization techniques for the preparation of aromatic polyesters from bisphenols and diacid chlorides are: interfacial polycondensation, 37,38 high-temperature solution polycondensation, 39 and low temperature solution polycondensation. 40,41 Generally, interfacial polycondensation is carried out under strongly alkaline conditions and hightemperature polycondensation requires temperature of 100 C or above.…”

Synthesis, characterization and post-modification of aromatic (Co)polyesters possessing pendant maleimide groups

“…The commonly used polymerization techniques for the preparation of aromatic polyesters involving bisphenols and diacid chlorides are: solution polycondensation either at ambient or high temperature [35][36][37] and interfacial polycondensation. [38][39][40] Interfacial polycondensation is carried out under alkaline conditions and high-temperature polycondensation requires temperature of 100 o C or above.…”

Synthesis and characterization of new aromatic polyesters containing pendent naphthyl units

“…A lot of efforts have been expended to improve the processing characteristics of aromatic polyesters. One of the approaches to obtain high T g and yet soluble polyesters is the introduction of bulky pendent groups along the polymer backbone 5–26…”