Polyethylene and Polypropylene Nanocomposites Based on Polymerically - Modified Clay Containing Alkylstyrene Units

Sodium montmorillonite was modified with a new polymeric surfactant. The high molecular weight of the surfactant appears to have led to incomplete cation exchange of the clays, but did promote nanocomposite formation with polyethylene and polypropylene. X-ray diffraction combined with transmission electron microscopy revealed a mixed nanocomposite morphology. The thermal stability of the nanocomposites was evaluated by thermogravimetric analysis, while flammability of the nanocomposites was evaluated by cone calorimetry. A significant 40% reduction in peak heat release rate was observed at 10% organo-clay (3% inorganic clay) loading with an even higher 50% reduction at a loading level of 16% modified clay (5% inorganic clay). Despite possible plasticization effects by the polymers used as an organic modification for the clays, the mechanical properties such as Young\u27s modulus and elongation were not severely impacted by the nanocomposite formation

Flammability of styrenic polymer clay nanocomposites based on a methyl methacrylate oligomerically-modified clay

Nanocomposites of polystyrene, high impact polystyrene, acrylonitrile–butadiene–styrene terpolymer, polypropylene, and polyethylene were prepared using a methyl methacrylate oligomerically-modified clay by melt blending and the thermal stability and fire retardancy were studied. These nanocomposites were characterized by X-ray diffraction, transmission electron microscopy, thermogravimetric analysis and cone calorimetry. The results show a mixed morphology, depending on the polymer

Fire properties of styrenic polymer–clay nanocomposites based on an oligomerically-modified clay

An oligomerically-modified clay has been used to fabricate nanocomposites with styrenic polymers, such as polystyrene, high-impacted polystyrene, poly(styrene-co-acrylonitrile) and acrylonitrile–butadiene–styrene by melt blending. The clay dispersion was evaluated by X-ray diffraction and bright field transmission electron microscopy. All of the nanocomposites have a mixed delaminated/intercalated structure. The fire properties of nanocomposites were evaluated by cone calorimetry and the mechanical properties were also evaluated

Methyl Methacrylate Oligomerically-Modified Clay and its Poly (Methyl Methacrylate) Nanocomposites

A methyl methacrylate oligomerically-modified clay was used to prepare poly(methyl methacrylate) clay nanocomposites by melt blending and the effect of the clay loading level on the modified clay and corresponding nanocomposite was studied. These nanocomposites were characterized by X-ray diffraction, transmission electron microscopy, thermogravimetric analysis and cone calorimetry. The results show a mixed intercalated/delaminated morphology with good nanodispersion. The compatibility between the methylacrylate-subsituted clay and poly(methyl methacrylate) (PMMA) are greatly improved compared to other oligomerically-modified clays

Polyethylene and Polypropylene Nanocomposites based upon an Oligomerically-Modified Clay

Montmorillonite clay was modified with an oligomeric surfactant, which was then melt blended with polyethylene and polypropylene in a Brabender mixer. The morphology was characterized by X-ray diffraction and transmission electron microscopy, while thermal stability was evaluated from thermogravimetric analysis and the fire properties by cone calorimetry. The nanocomposites are best described as mixed immiscible/intercalated/delaminated systems and the reduction in peak heat release rate is about 40% at 5% inorganic clay loading

Does organic modification of layered double hydroxides improve the fire performance of PMMA?

The effect of modified layered double hydroxides (LDHs) on fire properties of poly(methyl methacrylate) is investigated. Organically-modified LDHs were prepared via rehydration of calcined hydrotalcite in a palmitate solution. Composites consisting of the organo-LDHs, unmodified hydrotalcite and calcined oxides were prepared with poly(methyl methacrylate) using melt blending. Thermal and fire properties of the (nano)composites were studied. The thermogravimetric analyses of the composites show an increase in thermal stability. Fire performance, evaluated using cone calorimetry, show that organically-modified LDHs composites give the best reductions in peak heat release rate, PHRR, i.e., 51% at 10% weight loading. Dispersion of the LDHs was characterized using transmission electron microscopy and X–ray diffraction. Nanocomposite formation was observed with organically-modified LDHs, while the unmodified LDH composites gave only microcomposites