Soluble Polymers with Laterally Attached Oligophenyl Units for Potential Use as Blue Luminescent Materials

Abstract

New blue luminescent polyethers were prepared by interfacial polymerization of 2,5-diphenyl-, 2-biphenyl-, and 2,5-bis(biphenyl)hydroquinone diacetates with α,ω- dibromides. These polymers were soluble in common solvents, show liquid crystallinity in some cases, and can be melt processed at relatively low temperatures where they are thermally stable. Moreover their solid structure and corresponding properties (e.g. optical) can be controlled by judicious choice of the monomer unit. The synthesized polyethers were characterized by viscosimetry, gel permeation chromatography, thermal analysis, mechanical analysis, and UV−vis luminescence spectroscopy. The polymers show blue photoluminescence and have relatively low liquid crystalline transition temperatures, or they are amorphous depending on the symmetry of the substitution. The photoluminescent maxima were in the range 390−407 nm depending on the monomer structure. Free standing films were casted from solutions for some polymers, and in one case the mechanical properties were examined.

A Liquid Crystalline Elastomer with a p‐Pentaphenyl Transverse Rod Laterally Attached to the Main Chain

“…After 12 h, the cured film could easily be peeled from the pan by spraying a small amount of ethanol between the film A Liquid Crystalline Elastomer with a p-Pentaphenyl Transverse Rod Laterally Attached to the Main Chain Figure 1. Examples of LC polymers with laterally attached mesogenic rods: (a) 2,5-linked diester [2] ; (b) 2,6-linked diphenylpyrimidine [2] ; (c) 2,5-linked pentaphenyl [8] ; (d) 2,2 0 -linked quaterphenyl. [9] and pan.…”

“…There have been previous reports of laterally linked mesogens of high molar mass. [1][2][3][4][5][6][7] The meta linkage was chosen here because it could, in principle, produce a 908 angle between the pentaphenyl rod and the chain direction in the fully extended chain case.…”

The chemistry of electroluminescent organic materials

“…Furthermore, any type of functionalizable dye or charge transport material may be used as a side chain, allowing a great range of emission wavelengths and charge transport properties [209]. Examples of this strategy involve side-chain polymers such as poly(norbornene)s [210], poly(methacrylate)s [209,211,212], poly(styrene)s [208, 213 -215], poly(siloxane)s [216] poly(methyltetracyclododecene) [217] or polyethers [218] with different pendant chromophores.…”

Substituted poly(p-phenylene) oligomer as a physical crosslinker in Nafion® membrane

“…3). The former band can be attributed to the electron migration in the side-chain acetyl groups [24,25] while the latter one to the -* migration in the conjugated phenylene main chain [26,27]. It is rational to propose that the -* electron migration intensity will be weakened in response to the decrease of conjugation extent owing to the H + -association.…”