Poly (EA-MAn-APTES)/silica hybrid materials were successfully prepared fromEthyl acrylate (EA), maleic anhydride (MAn) and tetraethoxysilane (TEOS) in the presence of acoupling agent 3-aminopropyltriethoxysilane (APTE...Poly (EA-MAn-APTES)/silica hybrid materials were successfully prepared fromEthyl acrylate (EA), maleic anhydride (MAn) and tetraethoxysilane (TEOS) in the presence of acoupling agent 3-aminopropyltriethoxysilane (APTES),by free-radical solution polymerization and insitu sol-gel process. The mass fraction of TEOS varied from 0 to 25%. The hybrid materials werecharacterized by the methods of FT-IR spectra, solvent extraction, scanning electron microscope (SEM), transmission electron microscope (TEM), differential scanning calorimetry (DSC) andthermogravimetric analysis (TGA) measuring apparatus to get their structures, gel contents,morphologies, particle sizes and thermal performances. The results show that the covalent bonds arebetween organic and inorganic phases, gel contents in the hybrid materials are much higher, theSiO_2 phase is well dispersed in the polymer matrix, silicon dioxide exist at nanoscale in thecomposites and have excellent thermal stability.展开更多
Magnesium hydroxide(MH),which is commonly used as a halogen-free flame retardant filler in composite materials,was modified by silanization reaction with γ-aminopropyltriethoxysilane (γ-APS) in aqueous solution at d...Magnesium hydroxide(MH),which is commonly used as a halogen-free flame retardant filler in composite materials,was modified by silanization reaction with γ-aminopropyltriethoxysilane (γ-APS) in aqueous solution at different pH values (pH range from 8.0 to 12.0). The surface properties of grafted γ-APS on MH surface as a function of solution pH value were studied using elemental analysis,Fourier transform infrared spectroscopy and zeta potential measurement. The results show that hydrolysis and condensation of γ-APS are activated in alkaline solution and lead to multilayer adsorption of γ-APS molecules on the surface of MH. The type of adsorption orientation of γ-APS on MH surface is a function of coverage density that is altered by changing solution pH value. At low coverage density (e.g. 55 nm-2),γ-APS molecules are preferentially adsorbed to the surface with the silicon moiety towards the surface,and increasing coverage density (e.g. 90 nm-2) leads to parallel orientation. At an even higher coverage density (e.g. 115 nm-2),γ-APS molecules bond to the surface with the amino moiety towards the surface.展开更多
文摘Poly (EA-MAn-APTES)/silica hybrid materials were successfully prepared fromEthyl acrylate (EA), maleic anhydride (MAn) and tetraethoxysilane (TEOS) in the presence of acoupling agent 3-aminopropyltriethoxysilane (APTES),by free-radical solution polymerization and insitu sol-gel process. The mass fraction of TEOS varied from 0 to 25%. The hybrid materials werecharacterized by the methods of FT-IR spectra, solvent extraction, scanning electron microscope (SEM), transmission electron microscope (TEM), differential scanning calorimetry (DSC) andthermogravimetric analysis (TGA) measuring apparatus to get their structures, gel contents,morphologies, particle sizes and thermal performances. The results show that the covalent bonds arebetween organic and inorganic phases, gel contents in the hybrid materials are much higher, theSiO_2 phase is well dispersed in the polymer matrix, silicon dioxide exist at nanoscale in thecomposites and have excellent thermal stability.
基金Projects(50574104 50574102) supported by the National Natural Science Foundation of China
文摘Magnesium hydroxide(MH),which is commonly used as a halogen-free flame retardant filler in composite materials,was modified by silanization reaction with γ-aminopropyltriethoxysilane (γ-APS) in aqueous solution at different pH values (pH range from 8.0 to 12.0). The surface properties of grafted γ-APS on MH surface as a function of solution pH value were studied using elemental analysis,Fourier transform infrared spectroscopy and zeta potential measurement. The results show that hydrolysis and condensation of γ-APS are activated in alkaline solution and lead to multilayer adsorption of γ-APS molecules on the surface of MH. The type of adsorption orientation of γ-APS on MH surface is a function of coverage density that is altered by changing solution pH value. At low coverage density (e.g. 55 nm-2),γ-APS molecules are preferentially adsorbed to the surface with the silicon moiety towards the surface,and increasing coverage density (e.g. 90 nm-2) leads to parallel orientation. At an even higher coverage density (e.g. 115 nm-2),γ-APS molecules bond to the surface with the amino moiety towards the surface.
