Characterization of new formulations for the rotational molding based on ethylene-propylene copolymer/graphite nanocomposites

• Published in: Polymer engineering and science Vol. 48; no. 4; pp. 723 - 731
• Main Authors: Planes, Emilie, Duchet, Jannick, Maazouz, Abdherrahim, Gerard, Jean-François
• Format: Journal Article
• Language: English
• Published: Hoboken Wiley Subscription Services, Inc., A Wiley Company 01.04.2008; Wiley Subscription Services; Society of Plastics Engineers, Inc; Blackwell Publishing Ltd; Wiley-Blackwell
• Subjects: Applied sciences; Calcium carbonate; Chemical properties; Chemical Sciences; Composites; Exact sciences and technology; Forms of application and semi-finished materials; Graphite; Methods; Molding; Molds & molding; Nanotechnology; Nitric acid; Plastics; Polymer industry, paints, wood; Polymer processing; Polymers; Polyolefins; Stearic acid; Technology of polymers; United States; Rotational molding; Propylene copolymer; Olefin copolymer; Dispersion degree; Organic anhydride; Experimental study; Lamellar graphite; Property processing relationship; Functional polymer; Composite material; Surface treatment; Polymer filler interaction; Thermal properties; Structure processing relationship; Morphology; Ethylene copolymer; Thermal conductivity; Olefin polymer; Nanocomposite; Stearic acid
• ISSN: 0032-3888; 1548-2634
• DOI: 10.1002/pen.21012

In this article, ethylene–propylene copolymer/lamellar graphite nanocomposites were processed to be used in rotational molding. The addition of graphite aims at increasing the thermal conductivity of polyolefin and reducing processing cycle time. This article describes the different ways to get a well‐controlled dispersion of fillers in the matrix. For that, the control of the filler/matrix interactions is necessary. Graphite was treated with a concentrated nitric acid and sulfuric acid solution to lead to a graphite intercalation compound (GIC). By heating at high temperature, expanded lamellar graphite is so obtained. As the graphite surface energy is higher than polyolefin matrix one, the initial graphite and expanded graphite were treated with stearic acid, commonly used in the case of calcium carbonate, in order to match the surface energy of the hydrophobic matrix. In addition, as for clay‐polyolefin compounding, an interfacial modifier, i.e. a maleated ethylene–propylene copolymer (EP‐g‐MA) was added to improve the interactions between fillers and hydrophobic polyolefin matrix. POLYM. ENG. SCI., 2008. © 2008 Society of Plastics Engineers