Sequential self-repetitive reaction toward wholly aromatic polyimides with highly stable optical nonlinearity

Abstract

A sequential self-repetitive reaction (SSRR) based on carbodiimide (CDI) chemistry was utilized for preparing a high-yield wholly aromatic polyimide. The polyimide was synthesized with 4,4'-methylene-diphenylisocyanate (MDI) and a di(acid-ester) compound which was derived from the ring-opening reaction of 3,3',4,4'-oxydiphthalic dianhydride (ODPA) at room temperature by the addition of equimolar methanol. Poly-CDI was first synthesized from MDI. The di(acid-ester) compound was then reacted with poly-CDI to form poly(N-acylurea). After curing process, N-acylurea moiety was converted to di(ester-amide) structure via SSRR and further subjected to a ring-closure reaction to form the wholly aromatic polyimide with a T-g of 247 degrees C. This approach was further taken to prepare thermally stable nonlinear optical (NLO) materials. Similarly a diimide-diacid containing chromophore was reacted with poly-CDI to obtain an intermediate, poly(N-acylurea). The poly(N-acylurea) with the ester side groups would exhibit excellent organosolubility, which enabled the fabrication of high quality optical thin films. After in situ poling and curing processes, N-acylurea moiety was converted to di(ester-amide) structure via SSRR and further subjected to a ring-closure reaction to form the wholly aromatic NLO polyimide with an electro-optical coefficient, r(33) of 25 pm/V (830 nm). Excellent temporal stability at elevated temperatures (200 degrees C) and a waveguide optical loss of 2.5 dB cm(-1) at 1310 nm were also obtained

Synthesis of chromophores and polyimides with a green chemistry approach for second‐order nonlinear optical applications

“…Over the last 2 decades, a considerable number of NLO materials have been developed with organo‐metallic complexes, composite glasses impregnated with metal nanoparticles, semiconductors, and organic polymers . Very recently, chromophore‐containing polymers with second‐order NLO properties constitute a topic of sprouting interest owing to their potential applications in the area of frequency doubling for various electro‐optical and photonic devices . To address these practical applications, the polymeric NLO materials must have high optical quality thin films, high optical damage thresholds, sufficiently stable and large NLO susceptibilities, low optical propagation loss, and feasible device fabrication .…”

“…8,9 Very recently, chromophore-containing polymers with second-order NLO properties constitute a topic of sprouting interest owing to their potential applications in the area of frequency doubling for various electro-optical and photonic devices. [10][11][12] To address these practical applications, the polymeric NLO materials must have high optical quality thin films, high optical damage thresholds, sufficiently stable and large NLO susceptibilities, low optical propagation loss, and feasible device fabrication. 13,14 One of the benchmark features of a potential application is the long-term NLO stability at elevated temperatures.…”

A strategy for preparing spirobichroman dianhydride from bisphenol A and its resulting polyimide with low dielectric characteristic

“…All atomic volume contributions are referred to literature 35 (see Table 2 of this literature). Herein, we converted the unit fromÅ 3 per molecule to cm 3 mol À1 by multiplying by 0.602. The results are listed in Table 2.…”

“…Because of the rigid main chain and strong intermolecular interactions, aromatic polyimides (PIs) exhibit many attractive properties, such as outstanding high-temperature stability, [1][2][3] good chemical and solvent resistance, 4 and excellent mechanical properties. 4,5 Based on their advantages, PIs have been applied in electronics, 6,7 optics, and membranes.…”

Characterization of poly(amic acid)s and resulting polyimides bearing azobenzene moieties including investigations of thermal imidization kinetics and photoinduced anisotropy

“…These requirements are met by polyimides (PIs), which are an important class of high‐performance polymers useful in a variety of applications. Their excellent physicochemical properties such as optical and thermal stability in combination with high T g , low susceptibility to laser damage and low dielectric constant have led to broad spectrum of potential applications . PIs with azobenzene derivatives have already been investigated for photoinduced alignment in a liquid crystal display, as photomechanical response materials and for holographic recording .…”