A New Approach to Highly Electrooptically Active Materials Using Cross-Linkable, Hyperbranched Chromophore-Containing Oligomers as a Macromolecular Dopant

Abstract

A new, practical approach to a variety of highly electrooptically active polymers for device development is described. It involves the use of a new thermally cross-linkable, hyperbranched oligomer containing nonlinear optical (NLO) chromophores as a macromolecular dopant in a common host polymer. A series of NLO polymeric blends were readily formulated and showed large and stable electrooptic (EO) coefficients (up to 65 pm/V). In comparison with previously studied linear NLO polyimides and guest-host polymers doped with molecular chromophores and even linear NLO analogous oligomers, this new approach offers clear advantages for device development in terms of improved poling efficiency, larger EO coefficients, good temporal stability, and versatile material formulation.

The facile synthesis and optical nonlinearity of hyperbranched polyaspartimides with azobenzene dyes

“…This implies that aggregation of NLO dyes did not take place. It is important to note that the aggregation problem is often found in linear polymer systems [58]. With similar dye contents, the poled films of HBDAC23 and HBDAC12 exhibited r 33 values of 11.3 and 13.4 pm/V, respectively, which are two times larger than that of LDAC11, indicating a significant improvement in poling efficiency.…”

“…The product was purified by re-precipitations into water, and dried under vacuum. Yield: 58 Two compounds, 4,4-(1-phenylethylidene) (0.29 g, 1 mmol) and 2-chloro-5-nitrobenzo-trifluoride (0.4511 g, 2 mmol) were first dissolved in 20 cm 3 DMAc in a 50 cm 3 flask. After the mixture was completely dissolved, potassium carbonate (0.45 g, 2 mmol) was added to it in one portion.…”

Aromatic Hyperbranched Polymers: Synthesis and Application

“…The poled films exhibited EO coefficients (>50 pm/V) due to the 3D spatial isolation effect resulting from their highly branched structures. Bai et al [312] prepared thermally crosslinkable, hb oligomer containing NLO chromophores and blended it with linear host polymer. They obtained large and stable EO coefficients up to 65 pm/V, which are suitable for device development in terms of improved poling efficiency and temporal stability.…”

Further improvement of the macroscopic NLO coefficient and optical transparency of hyperbranched polymers by enhancing the degree of branching

“…Since HP3 would become insoluble quickly, we could not calculate its exactly yield, and only tested its 1 H NMR spectrum in order to calculate the DB value of these hyperbranched polymers. 1 …”