Thermoset-Layered Silicate Nanocomposites. Quaternary Ammonium Montmorillonite with Primary Diamine Cured Epoxies

Abstract

The role of various quaternary ammonium-modified montmorillonites in epoxy/diamine nanocomposite formation is examined to further refine the criteria for selection of organic modifiers necessary to enable fabrication of thermoset resins containing nanoscale dispersions of inorganic phases. Utilization of a hydroxyl-substituted quaternary ammonium modifier affords flexibility to combine both catalytic functionality, which increases the intragallery reaction rate, with enhanced miscibility toward both reagents. The rheological implications of these processing techniques are discussed with regards to using thermoset nanocomposites as a matrix in conventional fiber reinforced composites. The use of a low-boiling solvent to enhance mixability and processability of the initial mixtures is shown not to alter the structure or properties of the final nanocomposite. Also, the use of autoclave techniques enabled fabrication of high-quality specimens containing up to 20 wt % organically modified layered silicate (OLS). Finally, exfoliated and partially exfoliated epoxy/diamine nanocomposites were produced with enhanced heat-distortion temperature and increased flammability resistance.

The mechanical properties and fracture behaviour of epoxy-inorganic micro- and nano-composites

“…The present work has also shown that T g increases as the silicate loading increases. This is in agreement with published work by Brown et al [54] and Lee & Jang [55] where the same explanation is invoked: namely as the silicate loading is increased, so the surface area of the silicate is increased, and hence there are more interactions between the particles and the polymer, leading to higher constraint of the polymeric chains and a higher glass transition temperature.…”

The Properties of DSC and DMA for Epoxy Nano-and-Micro Mixture Composites

“…Regarding the large increase in the storage modulus in a rubbery state region based on these results, it can be definitely considered that the homogeneous dispersion and the excellent interfacial coupling force in a mixture state of the micro and nano particles limits the mobility of the epoxy molecules [10][11][12][13]. This can be detected in the cross-linking density.…”

Effect of temperature, duration and speed of pre-mixing on the dispersion of clay/epoxy nanocomposites

“…The intercalated or exfoliated forms of nanolayer silicates in many polymer systems have improved stiffness, strength, fracture toughness, fire resistance, barrier properties, and dimensional stability of the material [1][2][3][4][5][6]. The reinforcing ability of nanoclay is due to its high modulus, high strength and high aspect ratio.…”