Synthesis and Characterization of Hindered Polyphosphazenes via Functionalized Intermediates: Exploratory Models for Electro-optical Materials

Abstract

Several cosubstituent polyphosphazenes were synthesized that incorporate the nonlinear optical chromophore, disperse red 1 (DR-1), linked covalently to the polymer backbone through spacer groups. These polymers have a high chromophore loading (one DR-1 per repeat unit), have glass transition temperatures near 100 °C, and are high refractive index materials (n = ∼1.71). The syntheses were achieved via unconventional reactions that involve functionalized poly(organophosphazenes). Disperse red-1 was linked to the polymers by two different methods that generate either an ester- or an ether-linked system. Techniques such as 1H, 13C, and 31P NMR, gel permeation chromatography, differential scanning calorimetry, UV−vis spectroscopy, and optical birefringence were used to monitor the structures.

Synthesis and nonlinear optical properties of polyphosphazenes with binaphtholyl and indole side groups

“…Most polyphosphazenes have very high molecular weight, and they are usually amorphous, soluble, and easily prepared 1–4. Because of these advantages, they were considered as an excellent candidate for electrooptical (EO) applications 5–7. In 1991, a second‐order nonlinear optical (NLO) chromophore, dispersed red‐1 (DR‐1), was first linked to the phosphorus–nitrogen backbone by Allcock et al5 to synthesize new NLO polymeric materials; the resultant polyphosphazenes showed good properties such as stability and processibilty and demonstrated that polyphosphazenes might be promising polymeric materials for the NLO applications, except that T g was only 58°C.…”

Styrene/4-hydroxystyrene random, block and gradient copolymers modified with an organic dye: Synthesis by controlled radical polymerization and characterization of electrorheological properties

“…The schematic for the reaction pathway is shown in Scheme 1. (It should be noted that Allcock et al [34] employed a similar procedure to couple the DR1 chromophore to hydroxyl-functionalized polymers, with the hydroxyl units attached to phenyl rings, and achieved 100% coupling efficiency). Excess untethered DR1-TS was extracted by repeated flushing of the copolymer product with methylene chloride during a final filtering process until the methylene chloride being outputted from the filtering apparatus was clear for substantial time.…”

Second-order nonlinear optical properties of polyphosphazenes containing multi-dipolar and imidazolebased chromophores

“…They present a number of useful features for practical devices, such as the excellent flexibility of the backbone, high thermal and oxidative stability, optical transparency from 220 nm to the near-IR region, and controlled covalent incorporation of chromophores can be easily accomplished over a broad concentration range. Recently, some new synthetic routes [20][21][22][23][24][25][26] have been developed for the preparation of polyphosphazenes with large molecular hyperpolarizabilities and high glass-transition temperatures.…”