Preparation, thermal properties, morphology, and microstructure of phosphorus-containing epoxy/SiO2 and polyimide/SiO2 nanocomposites

• Published in: European polymer journal 2007-03, Vol.43 (3), p.725-742
• Main Authors: Lin, Ching Hsuan, Feng, Chen Chia, Hwang, Ting Yu
• Format: Article
• Language: English
• Subjects: Applied sciences; Composites; Exact sciences and technology; Forms of application and semi-finished materials; Polymer industry, paints, wood; Technology of polymers
• ISSN: 0014-3057; 1873-1945
• DOI: 10.1016/j.eurpolymj.2006.12.030

A phosphorus-containing tri-ethoxysilane (dopo-icteos) reacting from the nucleophilic addition reaction of 9,10-dihydro-9-oxa-10-phosphaphenanthrene 10-oxide (dopo) and 3-(trieoxysilyl) isocyanate (icteos) was synthesized. The structure of dopo-icteos was confirmed by 1H, 13C, 31P NMR and IR spectra. A triethylamine catalyzed mechanism for the dopo-icteos synthesis was proposed and verified by NMR spectra. The phosphorus-containing epoxy/SiO2 and polyimide/SiO2 nanocomposites were prepared from the in-situ curing of diglycidyl ether of bisphenol A (DGEBA)/4,4-diaminodiphenylmethane(DDM)/dopo-icteos, and imidization of poly(amic acid) of pyromellitic dianhydride (PMDA)/4,4'-oxydianiline (ODA)/dopo-icteos, respectively. The microstructure and morphology were investigated by 29Si NMR, scanning electron microscope (SEM), EDS (Si and P mapping) analysis and atomic force microscope (AFM). The thermal properties, flame retardancy and dielectric properties of the organic-inorganic hybrids were investigated by differential scanning calorimetry (DSC), dynamic mechanical analysis (DMA), limiting oxygen index (LOI), thermal gravimetric analysis (TGA) and dielectric analyzer (DEA).