Effect of nanosilica on the dielectric properties and thermal stability of polyimide/SiO₂nanohybrid

Abstract

New polyimide-silica (PI-SiO 2 ) nanohybrids were prepared by the reaction of bis(5-amino-1-naphthoxy) diphenylsilane (5-APS) with commercially available 4,4'-(Hexafluoroisopropylidene) diphthalic anhydride (6-FDA) in the presence of 3-aminopropyl triethoxysilane as a coupling agent and tetraethylorthosilicate (TEOS) as precursor of inorganic network. Hybrid thin films with 5-50 wt.% silica content were synthesized. The prepared PI-SiO 2 films were characterized by Fourier transform infrared spectroscopy and energy dispersive X-ray spectroscopy. The morphology and crystallinity of these hybrid systems were investigated by transmission electron microscopy and XRD analysis. Thermal properties of the nanohybrids were evaluated by thermogravimetric analysis and dynamic mechanical thermal analysis techniques. The optical constants (n and k) and dielectric parameters (e 0 and e 00 ) were calculated from IR reflection spectra by employing the Kramers-Kronig dispersion relations. Under proper condition, the silica particle size was in the range of 50-70 nm for the prepared hybrids. The results showed that presence of silica severely modified the properties of samples.

Poly(ether‐imide) and related sepiolite nanocomposites: investigation of physical, thermal, and mechanical properties

“…Much effort has been made to improve their processability via different synthetic methods such as introduction of flexible linkages or bulky side groups into the polymer backbone, reduction of molecular symmetry, and copolymerization. [13][14][15][16] Poly(ether-imide)s (PEIs) are a well-known class of highperformance co-PIs, which are characterized by their unique balance of thermal and mechanical properties. They reveal a combination of flexibility that is related to their ether linkages and superior thermal stability, which is attributed to the heterocyclic imide rings arranged alternatively in polymer structural units.…”

Thermally Stable and Processable Organic-Inorganic Hybrid Material

“…This decrease is in agreement with the increased silica content. The DE value is very much higher as compared to other hybrid material such as PI/SiO2 and PMMA/SiO2 which was reported earlier [32,33]. The reason for the increase of dielectric strength was due to the presence of polarizable bonds such as OH, C=O, C-N bonds contained in the (NIPAM-co-MA)/SiO2 hybrid material.…”

Nicotinic-based poly(amide-ether-imide)s: a new category of soluble, heat-resistant, and flame-retardant polyimides

“…These comprise outstanding physical properties, retention at elevated temperature and in wet environments, almost constant electrical properties over a wide range of temperatures, superior chemical resistance, and nonflammability properties. [5][6][7][8][9][10] However, one of the drawbacks to the employment of these high performance polymers is the difficulty in processing due to their high melting temperatures or high glass transition temperatures. Strong interaction between polyimide chains and their rigid structure are the major causes for these behaviors.…”