Preparation and characterization of aluminum oxide–poly(ethylene‐co‐butyl acrylate) nanocomposites

Abstract

This article describes the preparation and characterization of composites containing poly(ethylene-cobutyl acrylate) (EBA-13 and EBA-28 with 13 and 28 wt % butyl acrylate, respectively) and 2-12 wt % (0.5-3 vol %) of aluminum oxide nanoparticles (two types differing in specific surface area and hydroxyl-group concentration; uncoated and coated with, respectively, octyltriethoxysilane and aminopropyltriethoxysilane). A greater surface coverage was obtained with aminopropyltriethoxysilane than with octyltriethoxysilane. An overall good dispersion was obtained in the EBA-13 composites prepared by extrusion compounding. Composites with octyltriethoxysilanecoated nanoparticles showed the best dispersion. The addition of the nanoparticles to EBA-28 resulted in poor dispersion, probably due to insufficiently high shear forces acting during extrusion mixing which were unable to break down nanoparticle agglomerates. The nanoparticles had no effect on the crystallization kinetics in the EBA-13 composites, but in the EBA-28 composites the presence of the nanoparticles led to an increase in the crystallization peak temperature, suggesting that the nanoparticles had a nucleating effect in this particular polymer. V C 2011 Wiley Periodicals, Inc. J Appl Polym Sci 125: [975][976][977][978][979][980][981][982][983] 2012

Influence of nanoparticle surface treatment on particle dispersion and interfacial adhesion in low-density polyethylene/aluminium oxide nanocomposites

“…The C1-coated nanoparticles had the highest coverage of silane on the nanoparticle surface, 5.5 molecules (nm) À2 . This value was higher than the coverage of aminopropyltriethoxysilane on aluminium oxide nanoparticles reported by Nordell et al [6] and Wåhlander et al [7], which was attributed to the low steric hindrance of the methyl groups (C1) and the formation of multilayers in this silane coating. The silsesquioxane coverage was lower for the silanes with longer alkyl units ( Table 2).…”

“…Different methods have been used to prepare polymer nanocomposites, including melt mixing [6], solution mixing [7] and in-situ polymerisation [8]. The incompatibility between nanoparticles and polymer matrix is usually a challenge and it may lead to particle agglomeration and void formation in the composites, which in some cases have detrimental effects on the performance of the materials [9].…”

Prebreakdown current and dc breakdown strength of alumina-filled poly(ethylene-co-butyl acrylate) nanocomposites: Part I - breakdown strength

“…The ND particles had a near spherical shape with an average particle diameter of 45 nm and the specific surface area of 36 m 2 /g. SEM analysis of uncoated ND particles as received from manufacturer showed that the average particle diameter is ca 45 nm [9]. The SEM pictures of both types of nanoparticles are shown in Figure1.…”

“…Aminopropyltriethoxy silane and octyltriethoxy silane were used for surface modification of the nanoparticles and were supplied by Sigma-Aldrich and Fluka respectively. According to TGA the grafting density was calculated to be: 0.4 -1.4 octylterminated silane molecules and 1.4 -2.5 amino-terminated silane molecules per square nanometer for ND and NA nanoparticles respectively; based on the assumption that a uniform silane layer was formed around each nanoparticle [9]. The stabilizer Irganox 1010 (a hindered phenolic antioxidant) was provided from Ciba Specialty Chemicals, Germany.…”

Dielectric breakdown strength of alumina filled poly (ethylene-co-butyl acrylate) nanocomposites

“…The alumina nanoparticles used were almost completely spherical with diameter < 50 nm according to the data from the manufacturer. Examining uncoated particles as received from manufacturer showed that the average particle diameter is ca 45 nm [8], see Figure 1. …”