scholarly journals Preparation and Performance of Nano-hybrids Synthesized from Polyimide and Silica

2009 ◽  
Vol 2 (1) ◽  
pp. 99-107 ◽  
Author(s):  
S. M. M. Alam
Keyword(s):  
Sol Gel ◽  
Tensile Modulus ◽  
Mechanical Analysis ◽  
Hybrid Films ◽  
Scanning Calorimetry ◽  
Chemical Structures ◽  
Sol Gel Process ◽  
Biphenyltetracarboxylic Dianhydride ◽  
Silica Hybrid

Polyimide (PI)-inorganic like silica hybrid films were successfully prepared to combine the good performances of silica like tensile modulus, thermal stability etc. into organic PI. Polyamic acid (PAA), precursor of PI, was prepared from 3, 3′, 4, 4′-biphenyltetracarboxylic dianhydride (BPDA), p-phenylediamine (PDA) and in-situ formed silica was formed into PAA from tetraethoxysilane (TEOS) through in-situ sol-gel process. The films were transparent and became translucent in presence of up to 10% inorganic contents. The chemical structures were characterized by Fourier transform infrared spectroscopy (FTIR). The morphology of the films was investigated by scanning electronic microscopy (SEM). Differential scanning calorimetry (DSC), thermogravimetry analysis (TGA), stress-strain tests and dynamic mechanical analysis (DMA) were used to evaluate the performances of the films. The results indicated that the glass-transition temperatures (Tg) and decomposition temperatures of the PI-silica hybrid films were higher than those of pristine PI. Tensile modulus, tensile strength of PI increased prominently in presence of small amount (1%) of silica in PI-silica hybrid. Keywords: Polyimide; Hybrid; Sol-gel process. © 2010 JSR Publications. ISSN: 2070-0237 (Print); 2070-0245 (Online). All rights reserved. DOI: 10.3329/jsr.v2i1.2733                 J. Sci. Res. 2 (1), 99-107 (2010)  

Synthesis and Intermolecularly Mediated Assembly of Organic Pigment in Hybrid Coating Films

1998 ◽  
Vol 519 ◽  
Author(s):  
Y. Yan ◽  
Z. Duan ◽  
D.-G. Chen ◽  
S. Ray Chaudhuri
Keyword(s):  
Sol Gel ◽  
Hybrid Coating ◽  
Hypsochromic Shift ◽  
Hybrid Films ◽  
Coating Films ◽  
Organic Pigment ◽  
Inorganic Hybrid ◽  
Matrix Interactions ◽  
Sol Gel Process

AbstractThe insoluble, strongly hydrogen bonded organic pigment of 3,6-bis-(4-chlorphenyl)-l,4- diketopyrrolo [3,4-c] pyrrole was transiently blocked by adding carbamate groups, and consequently incorporated into organic-inorganic hybrid matrices by a sol-gel process. The homo- (pigment-pigment) and hetero-intermolecular (pigment-matrix) interactions were found to control both the assembly and dispersion of pigment molecules in the hybrid coating films. A weaker interaction between matrices and pigment molecules results in aggregation of the carbamate pigment in the methyl-silicate films. A stronger interaction forms a homogenous dispersion and coloration of the phenyl-silicate films. The as-prepared methyl- and phenylsilicate films doped with the organic pigment were distinguished by a morphology change and a blue (hypsochromic) shift in absorption from 550 to 460 nm. Thermal treatment can remove the carbamate groups and in-situ form the organic pigment in the hybrid films.

The preparation of poly(methylsilsesquioxane) network-polyimide hybrid materials by the sol-gel process and their properties

1994 ◽  
Vol 6 (1) ◽  
pp. 43-52 ◽  
Author(s):  
Yoshitake Iyoku ◽  
Masa-aki Kakimoto ◽  
Yoshio Imai
Keyword(s):  
Hybrid Materials ◽  
Sol Gel ◽  
Tensile Modulus ◽  
Hybrid Films ◽  
Elongation At Break ◽  
Dimethyl Acetamide ◽  
Flexible Films ◽  
Sol Gel Process ◽  
Heating Up ◽  
Silicone Content

Poly(methylsilsesquixoane) network (silicone)-polyimide hybrid materials were successfully prepared by the sol-gel reaction of methyltriethoxysilane (MTES). The ethoxysilyl group in MTES was hydrolyzed and polycondensed in the solution of the polyamic acid, derived from pyromellitic dianhydride and bis(4-aminophenyl)ether, in N,N-dimethyl-acetamide (DMAc). The hybrid films were obtained by casting the reaction mixture, followed by heating up to 300°C. The hybrid materials containing 0-60wt% of silicone afforded flexible films. The films containing less than 7 wt% silicone were yellow and transparent, whereas the films with higher silicone content were yellow and opaque. Silicone particles with a diameter of around 1-10 μm were observed in the fracture surface of the hybrid films by scanning electron microscopy. Although the tensile strength and tensile modulus of the films obtained decreased with increasing silicone content. the value of the elongation at break remained at 60% up to 30% silicone content.

scholarly journals Preparation of Polyimide-Silica Hybrid Films Using Sol-Gel Process.

1992 ◽  
Vol 5 (2) ◽  
pp. 393-396 ◽  
Author(s):  
Atsushi Morikawa ◽  
Hidehiro Yamaguchi ◽  
Yoshitake Iyoku ◽  
Masa-aki Kakimoto ◽  
Yoshio Imai
Keyword(s):  
Sol Gel ◽  
Hybrid Films ◽  
Sol Gel Process ◽  
Silica Hybrid

Preparation and properties of polyimide-polysiloxane hybrid materials by the sol-gel process

1994 ◽  
Vol 6 (2) ◽  
pp. 95-107 ◽  
Author(s):  
Yoshitake Iyoku ◽  
Masa-aki Kakimoto ◽  
Yoshio Imai
Keyword(s):  
Solution Method ◽  
Sol Gel ◽  
Mechanical Analysis ◽  
Methanol Solution ◽  
Heating Process ◽  
Hybrid Films ◽  
Polyamic Acid ◽  
Sol Gel Process ◽  
Solution Methods ◽  
Polyimide Matrix

Polyimide-poly(methylsiloxane) hybrid films were successfully prepared by the sol-gel process with methyltriethoxysilane (MTES) and/or dimethyldiethoxysilane (DMDES) in the polymer solution. Two methods were used for making hybrid films. First, MTES and/or DMDES were dissolved in the N,N-dimethylacetamide (DMAc) solution of the polyamic acid (polyimide precursor) prepared from 4,4'-diaminodiphenyl ether (ODA) and pyromellitic dianhydride (PMDA). During the heating process at 300°C the polyamic acid was converted to polyimide and the sol-gel reaction, which consists of hydrolysis and condensation of MTES and/or DMDES, proceeded simultaneously. Second, methanol was used as the solvent to make the hybrid films by using the triethylamine salt of polyamic acid. The IR spectra proved that the sol-gel reactions started from MTES and DMDES readily proceeded in the polymer matrix. The hybrid films prepared in methanol were more transparent than those prepared in DMAc. Measurement by dynamic mechanical analysis indicated that the polystloxane was dispersed homogeneously in the polyimide matrix even after the heat treatment at 300°C, in the case of both DMAc and methanol solution methods. With respect to the tensile properties, the tensile strength and the elongation at break of the hybrid films prepared by the methanol solution method were higher than those by the DMAc solution method. The modulus of the obtained hybrid films decreasing with increasing DMDES ratio in the silicone unit in both cases.

Polypropylene wax (PPw)/silica hybrid by in situ non-aqueous sol–gel process for preparation of PP/silica nanocomposites

2010 ◽  
Vol 56 (3) ◽  
pp. 300-309 ◽  
Author(s):  
Jun Qian ◽  
Huagui Zhang ◽  
Guangchun Cheng ◽  
Zhijuan Huang ◽  
Shuaiying Dang ◽  
...  
Keyword(s):  
Sol Gel ◽  
Silica Nanocomposites ◽  
Sol Gel Process ◽  
Silica Hybrid

The preparation of new poly(phenylsilsesquioxane)-polyimide hybrid films by the sol-gel process and their properties

1994 ◽  
Vol 6 (1) ◽  
pp. 53-62 ◽  
Author(s):  
Yoshitake Iyoku ◽  
Masa-aki Kakimoto ◽  
Yoshio Imai
Keyword(s):  
Nmr Spectra ◽  
Sol Gel ◽  
Tensile Modulus ◽  
Heating Process ◽  
Hybrid Films ◽  
Polyamic Acid ◽  
Sol Gel Process ◽  
Polyimide Matrix ◽  
Polyimide Precursor ◽  
Silicone Content

The preparation of poly(phenylsilsesquioxane)-polyimide hybrid films was successfully performed with phenyltriethoxysilane (PhTES) and the polyamic acid (polyimide precursor) prepared from 4.4'-oxydianiline (ODA) and pyromellitic dianhydride (PMDA). During the heating process at 300 C, the imidization of the polyamic acid and the sol-gel reaction, hydrolysis and condensation of PhTES, proceeded simultaneously. The IR spectrum and the t3C-NMR and 29Si-NmR spectra showed that the sol-gel reaction of PhTES proceeded in the polymer matrix with high conversion. The hybrid films with a silsesquioxane content up to 75 wt% were obtained as the self-standing form. The hybrid films having a silsesquioxane content of 45 wt% were yellow and transparent, and those having more silicone content were yellow and translucent. The therma] properties of the hybrid films were improved to some extent by the introduction of the silsesquioxane component into the polyimide matrix. With respect to the tensile properties. the tensile strength remained around 85 MPa up to a silicone content of 45 wt%. This value was twice that of the hybrid films based on methyltriethoxysilane. The tensile modulus decreased with increasing silsesquioxane content.

Formation of Interconnected Globular Structure of Silica Phase in Polyimide-Silica Hybrid Films Prepared by the Sol-Gel Process

1994 ◽  
Vol 6 (7) ◽  
pp. 913-917 ◽  
Author(s):  
Atsushi Morikawa ◽  
Hidehiro Yamaguchi ◽  
M. Kakimoto ◽  
Yoshio Imai
Keyword(s):  
Sol Gel ◽  
Hybrid Films ◽  
Globular Structure ◽  
Silica Phase ◽  
Sol Gel Process ◽  
Silica Hybrid

Synthesis and cryogenic properties of polyimide–silica hybrid films by sol–gel process

Polymer ◽  
2005 ◽  
Vol 46 (19) ◽  
pp. 8373-8378 ◽  
Author(s):  
Yi-He Zhang ◽  
Yan Li ◽  
Shao-Yun Fu ◽  
John H. Xin ◽  
Walid A. Daoud ◽  
...  
Keyword(s):  
Sol Gel ◽  
Hybrid Films ◽  
Sol Gel Process ◽  
Silica Hybrid
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