Synthesis and Characterization of Soluble Aromatic Polyesters Containing Oligophenyl Moieties in the Main Chain

Abstract

A series of rigid aromatic polyesters containiig substituted oligophenyls wasprepared. Aliphatic and aromatic side groups were used to increase the solubility. New oligophenyldiols were synthesized by coupling aromatic Grignard reagenta with aromatic halides, using palladium complexes as catalysta. The polyesters were prepared by melt polycondensation and characterized by viscosimetry, thermal analysis, and dynamic mechanical analysis. The temperature dependence of the intrinsic viscosity, in the range 30-85 O C , was sensitive to the type and position of the side groups. Polyesters with aromatic substituents were stable up to 400 "C. The glass transition temperatures of the polyesters with aromatic side groups were in the range 150-250 "C. Dynamic mechanical analysis showed that in the cases where aromatic Substituents were used to increase solubility, the obtained polymers appear to have useful mechanical properties at high temperatures. The glass transitions appeared in the range 160-220 "C, while a plateau modulus in the range of 108 Pa was obtained at high temperatures (up to 350 O C ) .

Synthesis and properties of new polyarylates from 1,4-bis(4-carboxyphenoxy)naphthyl or 2,6-bis(4-carboxyphenoxy)naphthyl and various bisphenols

“…14 -16 A comparison of the mechanical properties behavior of the system studied here with that of another polyester, studied by Kallitsis,14,15 showed that the main difference was the relatively high temperature of ␤ transition appearing in the relatively short side chain (methyl group) in this article. In addition, the glass transition at around 225°C is associated with an approximately 2 orders of magnitude decrease in GЈ.…”

Synthesis and properties of amorphous blue‐light‐emitting polymers with high glass‐transition temperatures

“…Chemicals were purchased from Aldrich and used as received unless otherwise specified. 2,5‐Dialkoxy‐1,4‐phenyldiboronic acids,29 2,5‐dialkyl‐1,4‐phenyldiboronic acid,30 2′,3′,5′‐triphenyl‐ p ‐terphenyl‐4‐4″‐diol,31 2″,3″,5″‐triphenyl‐ p ‐quinquephenyl‐4‐4″″‐diol,31 2′,5′‐dihexyloxy‐ p ‐terphenyl‐4‐4″‐diol,32 2″,5″‐dihexyloxy‐ p ‐quinquephenyl‐4‐4″″‐diol,18 4‐acetoxybromobenzene, 4‐acetoxy‐4′‐bromobiphenyl,33 and bis(fluorophenyl)phenylphosphine oxide34 were synthesized according to reported procedures. Dimethylformamide (DMF) was distilled and kept under molecular sieves.…”

Synthesis and Characterization of Poly(azomethine ester)s with a Pendent Dimethoxy Benzylidene Group

“…But their poor solubility in organic solvents often restricts its use for many applications. Thus, it is clear that various structural changes should be made in the poly(azomethine ester)'s chain to obtain better solubility and its application in various fields [9][10][11][12][13][14][15]. Some of the reported methods to improve the processability of conjugated poly(azomethine)s are by incorporation of unsymmetrical or symmetrical substitutions in the main-chain aromatic benzene rings with flexible alkyl or alkoxy side chains and reversible Lewis acidbase complexation [16][17][18][19].…”