Polyimide–silica hybrid coatings: morphological, mechanical, and thermal investigations

Abstract

In this study, polyimide-silica (PI-silica) based hybrid coating compositions were prepared from tetraethoxysilane (TEOS), g-glycidyloxypropyl trimethoxy silane (GOTMS), and polyamic acid (PAA) via a combination of sol-gel and thermal imidization techniques. PAA was synthesized from 3,3(,4,4(-benzophenone tetracarboxylic dianhydride (BTDA) and 3,3'-Diaminodiphenyl sulfone (DDS) in N-Methyl-2-pyrrolidone (NMP). The silica content in the hybrid coatings was varied from 0 to 20 wt%. The structural characterization of the hybrid coatings was performed using FTIR and 29 Si-NMR spectroscopies. Results from both pendulum hardness and micro indentation test show that the hardness of hybrid coatings improves with the increase in silica content. The tensile tests also demonstrated that the mechanical properties at low silica content are rather striking. Their surface morphologies were characterized by scanning electron microscopy (SEM). SEM studies revealed that inorganic particles were distributed homogenously through the PI matrix. It was also found that, incorporation of the silica domains increased the thermal stability of the hybrid coatings.

Synthesis and characterization of novel polyimide/SiO2 nanocomposite materials containing phenylphosphine oxide via sol‐gel technique

“…For that reason, surface morphology of the hybrid coating materials is of great importance for many technical applications. 4 The morphologies of the fractured surfaces of the hybrid films with different silica content were investigated by SEM. In Figure 5 (a-c), it can be observed that silica particles are homogenously dispersed through the polyimide matrix.…”

“…[1][2][3] For that reason, they have found many technological applications in the aerospace, microelectronic, and other advanced technologies. 4 In addition, PIs have been considered as suitable polymer matrix materials for preparation of advanced hybrid composites.…”

Physics and Chemistry of Sol-Gel Nanocomposites Formation

“…They are obtained by the scheme (Fig. 4.17) [143]. Thus, properties of PA-66 semi-crystal thermoplastic can be improved by silica gel nanoparticles (10-100 nm) [144][145][146][147].…”

“…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. Hardness of these coatings increases with increase in SiO 2 content, tensile tests shows significant improvements, inorganic particles are distributed homogeneously in PI matrix.…”

Polymer/organosilica nanocomposites based on polyimide with benzimidazole linkages and reactive organoclay containing isoleucine amino acid: Synthesis, characterization and morphology properties

“…On the other hand, further improvement of the PI properties such as higher thermal stability and lower dielectric constant by the introduction of different nanoparticles makes these materials a good choice for preparation of hybrid materials to development of next generation resources which act in response to the demand of highly very tiny electronic devices, super conductive materials, and modern spacecrafts [10][11][12]. Various combinations of PIs with inorganic fillers including silica, a layered silicate such as montmorillonite or mica, aluminum nitride, titania, barium titanate and carbon nano-tubes have been reported.…”