Synthesis and properties of new polyimide/clay nanocomposite films

• Published in: Bulletin of materials science 2013-10, Vol.36 (5), p.789-798
• Main Authors: MANSOORI, YAGOUB, SANAEI, SOMAYEH SHAH, ZAMANLOO, MOHAMMAD-REZA, IMANZADEH, GHOLAMHASSAN, ATGHIA, SEYED VAHID
• Format: Article
• Language: English
• Subjects: Acids; Chemistry and Materials Science; Clay; Clay (material); Dielectric properties; Diffraction patterns; Dimethyl acetamide; Dimethyl sulfoxide; Dispersions; Engineering; Glass transition temperature; Interlayers; Materials Science; Mechanical properties; Montmorillonite; Nanocomposites; Nanomaterials; Nanostructure; Polyimide resins; Polymers; Silica; Solvents; Surface roughness; Thermodynamic properties; Uptakes
• ISSN: 0250-4707; 0973-7669
• DOI: 10.1007/s12034-013-0542-4

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.