Polymer nanocomposite

About: Polymer nanocomposite is a research topic. Over the lifetime, 8977 publications have been published within this topic receiving 297599 citations.

Fire Retardant Halogen-Antimony-Clay Synergism in Polypropylene Layered Silicate Nanocomposites

Abstract: Nanocomposites of polypropylene-graft-maleic anhydride with organically modified clays have been prepared and characterized by X-ray diffraction and transmission electron microscopy. Their combustion behavior has been evaluated using oxygen consumption cone calorimetry. Synergy is observed between the nanocomposite formed and conventional vapor phase fire retardants, such as the combination of decabromodiphenyloxide and antimony oxide. The presence of bromine and antimony does not affect the heat release rate curves of the virgin polymer.

Temperature dependent mechanical properties of graphene reinforced polymer nanocomposites – A molecular dynamics simulation

Abstract: This paper investigates the mechanical properties of graphene/PMMA nanocomposite system by using the molecular dynamics simulations. The graphene nanoplates are assumed to be fully exfoliated in the PMMA matrix and are all planar orientated, which are similar to the ones assembled using layer-by-layer technique. The Young's modulus and shear modulus of the composites with different graphene volume fractions under different temperatures are simulated and discussed. The results show that the Young's and shear moduli increase with the increase of graphene volume fraction and decrease as the temperature rises from 300 K to 500 K, while the efficiency of the reinforcement is reduced as the graphene content becomes higher. Simulations of single layer graphene under uniaxial tension, in-plane pure shear and uniformly distributed transverse load are performed and the effective thickness and the elastic moduli of graphene are subsequently determined uniquely. The obtained stiffnesses of graphene are then substituted into the simple rule of mixture to predict the overall mechanical properties of the composite. Large discrepancies between the results from the MD simulations and the rule of mixture are observed.

Mechanical Reinforcement of Polyethylene Using Polyethylene‐Grafted Multiwalled Carbon Nanotubes

Abstract: The incorporation of carbon nanotubes to a polymer generally improves the stiffness and strength of the polymer, but the ductility and toughness of the polymer are compromised in most cases. Here we report the mechanical reinforcement of polyethylene (PE) using polyethylene-grafted multiwalled carbon nanotubes (PE-g-MWNTs). The stiffness, strength, ductility and toughness of PE are all improved by the addition of PE-g-MWNTs. The grafting of PE onto MWNTs enables the well-dispersion of nanotubes in the PE matrix and improves MWNT/PE interfacial adhesion. The grafting was achieved by a reactive blending process through melt blending of PE containing 0.85 wt % of maleic anhydride and amine-functionalized MWNTs. The reaction between maleic anhydride and amine groups, as evidenced by X-ray photoelectron spectroscopy and Raman spectroscopy, leads to the grafting of PE onto the nanotubes.

Polymeric Nanocomposites for Tribological Applications

Abstract: Polymer nanocomposites operate in applications where fluid and grease lubricants fail, and have superior tribological performance to traditional polymer composites. Nanoparticle fillers have been a part of notable reductions in the wear rate of the polymer matrix at very low loadings. Despite instances of remarkable wear reductions at unprecedented loadings (3 000 times at 0.5% loading in one case), there is a lack of general agreement within the literature on the mechanisms of wear resistance in these nanocomposites. In addition, results appear to vary widely from study to study with only subtle changes of the filler material or blending technique. The apparent wide variation in tribological results is likely a result of processing and experimental differences. Tribology is inherently complex with no governing laws for dry sliding friction or wear, and the state of the art in polymeric nanocomposites tribology includes many qualitative descriptors of important system parameters, such as particle dispersion, bulk mechanical properties, debris morphology, and transfer film adhesion, morphology, composition, and chemistry. The coupling of inherent tribological complexities with the complicated mechanics of poorly characterized nanocomposites makes interpretation of experimental results and the state of the field extremely difficult. This paper reviews the state of the art in polymeric nanocomposites tribology and highlights the need for more quantitative studies. Examples of such quantitative measurements are given from recent studies, which mostly involve investigation of polytetrafluoroethylene matrix nanocomposites.