Stable second‐order nonlinear optical poly(amide–imide)/inorganic materials via simultaneous sequential self‐repetitive reaction and sol–gel process

Abstract

A series of thermally stable organic/inorganic second-order nonlinear optical (NLO) composites via sequential self-repetitive reaction (SSRR) and sol-gel process has been developed. This SSRR is based on carbodiimide (CDI) chemistry. The difunctional azo chromophores (2,4-diamino-4'-(4-nitrophenyl-diazenyl)azobenzene (DNDA)) was reacted with excessive amount of 4, 4'-methylenediphenylisocyanate (MDI) to form poly-CDI, and subsequently trimellitic anhydride (TMA) was added to obtain poly(N-acylurea). The organic/inorganic composites containing prepolymer of phenyltriethoxysilane (PTEOS) and poly(N-acylurea) in different weight ratios (10:90, 30:70, 50:50, 70:30, 90:10 wt%) were prepared, respectively. The moderate glass transition temperature (T-g) characteristic of the poly(N-acylurea) allows the NLO-active polymer to achieve high poling efficiency. After in situ poling and curing process, the T(g)s of the composites were elevated, and higher than that of the pristine poly(amide-imide) sample. Electro-optical (EO) coefficients (r(33)) Of about 5.5 similar to 18.0 pm/V at 830 nm were obtained. Excellent temporal stability at 100 degrees C, and waveguide characteristics (3.1-4.2 dB/cm at 830 nm) were also obtained for these composites. Copyright (C) 2008 John Wiley & Sons, Ltd

Nonlinear optical, poly(amide-imide)–clay nanocomposites comprising an azobenzene moiety synthesised via sequential self-repetitive reaction

“…This would lead to a significant decrease of NLO density, i.e. optical nonlinearity [20]. In this work, by dispersing a small amount of organoclay into the NLO poly(amide-imide), the thermal properties can be increased noticeably without the disadvantage of the reduced NLO density.…”

“…In our recent investigation [19], NLOactive poly(amide-imide)s obtained via sequential self-repetitive reaction (SSRR) have been systematically studied. In addition, organic/inorganic NLO-active nanocomposites were prepared by performing SSRR of poly(N-acylurea) and sol-gel process of phenyltriethoxysilane, concurrently [20]. Because of the formation of the three-dimensional silicon oxide networks, long-term NLO stability at elevated temperatures was greatly enhanced.…”

“…A lower imidization temperature would help in enhancing the poling efficiency, i.e. NLO properties [20].…”

Physics and Chemistry of Sol-Gel Nanocomposites Formation

“…At high content of inorganic phase mechanical and thermal properties deteriorate, which is caused by aggregation of silica gel particles in the hybrid. These polyamides are promising candidates for usage in microelectronics [168], other types of sol-gel products of similar composition are promising for production of membranes with high gas transporting properties [169], ceramics [170], nonflammable nanocomposites [171], materials with low dielectric permeability [172,173] and with stable optical properties for non-linear optics, [174], etc. Also widely used are polyamide-silica gel hybrid coatings (0-20 wt% SiO 2 ), which are obtained, for example, from PI, TEOS, glycidyloxypropyl trimethoxysilane and polyamic acid (synthesized from 3, 3, 4 benzophenone tetracarboxylic dianhydride (BTDA) and 3,3 0 -Diaminodiphenyl sulfone)(DDS) [143]), combination of sol-gel technique with Scheme 4.7 Covalent binding of nanoparticles with a polymer chain by 3-glycidiloxytrimethoxy silane thermal imidization.…”

New photosensitive poly(amid‐imide)s containing chalcone moiety and hydantoin derivatives in the main chain: Synthesis and characterization

“…They are finding numerous applications in adhesives, electronic wire enamel, injection-molding, extrusion products, and membranes. 10,[13][14][15][16][17] In our pervious articles, we described synthesis and characterization of different poly(amide-imide)s containing heterocyclic segments in the main chain such as hydantoin, pyridyl, and tetrahydropyrimidine rings with improved solubility and thermal properties. [18][19][20][21][22][23][24][25][26][27] Photosensitive polymers are widely used as polymeric photo resists in the field of microelectronics.…”