Synthesis and properties of new polyimide/clay nanocomposite films

Abstract

A series of polymer-clay nanocomposite (PCN) materials consisting of polyimide and typical clay were prepared by solution dispersion. Quaternary alkylammonium modified montmorillonite, Cloisite 20A, was used as organoclay. Poly(amic acid) solution was prepared from the reaction of benzophenone-4,4 ,3,3-tetracarboxylic dianhydride and 2-(5-(3,5-diaminophenyl)-1,3,4-oxadiazole-2-yl) pyridine in dimethylacetamide. Thermal imidization was performed on poly(amic acid)/organoclay dispersion in a regular temperature-programmed circulation oven. The study of interlayer d-spacing with X-ray diffraction pattern indicates that an exfoliated structure may be present in the nanocomposite 1%. Intercalated structures were obtained at higher organoclay loadings. Nanocomposites were studied using thermogravimertic analysis and differential scanning calorimetry. Nanocomposites exhibit higher glass transition temperature and improved thermal properties compared to neat polyimide due to the interaction between polymer matrix and organoclay particles. The results are also compared with data of a similar work. Morphology study with scanning electron microscopy showed that the surface roughness in nanocomposite 1% increased with respect to pristine polyimide. Solvent uptake measurements were also carried out for the prepared materials. Maximum solvent adsorption was observed for dimethyl sulfoxide (DMSO). It was found that the solvent uptake capacity decreased with increasing clay content.

Morphological, Thermal, Mechanical and Solvent Uptake of Clay/Nylon 6,6 Composites

“…The decrease of solvent uptake by clay/polyimide nanocomposite was also reported by Mansoori et al [21]. They suggested that there is a strong interaction between polyimide and montmorillonite and the excellent barrier properties of the large aspect ratio silicate, which enhanced the available surface area of the fillers.…”

Synthesis and Characterization of Organosoluble, Thermal Stable and Hydrophobic Polyimides Derived from 4-(4-(1-pyrrolidinyl)phenyl)-2,6-bis(4-(4-aminophenoxy)phenyl)pyridine

“…In addition, the presence of nitrogen atoms in pyridine rings can generate polarized bonds, which increase the solubility of polymers due to the intermolecular dipole-dipole interactions in a polymer-solvent system [41,42,43]. For example, PIs derived from 2-(5-(3,5-diaminophenyl)-1,3,4-oxadiazole-2-yl)pyridine [44] and 1,3-bis(5-amino-2-pyridinoxy)benzene [45] have all have been demonstrated to own high solubility and thermal properties. Li et al [46] reported a class of cardo-type polyimides with cyclopentyl-containing alicyclic units as side groups.…”

Studies on thermoset blend of bismaleimide having multiple swivel groups and biscyanate ester

“…Apart from the well-known brittleness, the common detrimental property of cured bismaleimides owing to the high cross linking densities, these materials are having several advantageous properties like excellent thermal stability, long shelf life, low moisture absorption, excellent adhesion, low dielectric constant and several acceptable physico mechanical properties. 10,11 The fine tuning of the thermal properties of bismaleimide matrix resin is possible through the modification of the structural entities present in between the maleimide groups. 12 The aromatic structure is thermally stable compared to the aliphatic structure.…”