Nanocomposites of silica reinforced polypropylene: Correlation between morphology and properties

• Published in: Polymer engineering and science Vol. 54; no. 9; pp. 2187 - 2196
• Main Authors: Bouaziz, Amira, Jaziri, Mohamed, Dalmas, Florent, Massardier, Valerie
• Format: Journal Article
• Language: English
• Published: Hoboken, NJ Blackwell Publishing Ltd 01.09.2014; Wiley; Society of Plastics Engineers, Inc; Wiley-Blackwell
• Subjects: Agglomeration; Applied sciences; Chemical Sciences; Comparative studies; Compatibility; Composites; Correlation analysis; Exact sciences and technology; Extrusion; Forms of application and semi-finished materials; Material chemistry; Materials research; Mechanical properties; Morphology; Nanocomposites; Nanostructure; Plastics; Polymer industry, paints, wood; Polymers; Polypropylene; Polypropylenes; Production processes; Reagents; Reinforced plastics; Silica; Silicon dioxide; Storage modulus; Technology of polymers; Thermal properties; Thermal stresses; Strengthening; Storage modulus; Dispersion degree; Propylene polymer; Mechanical properties; Dispersion reinforced material; Tensile property; Organic anhydride; Experimental study; Compatibilizer; Functional polymer; Composite material; Thermal properties; Melt crystallization; Morphology; Concentration effect; Silica fume; Extrusion; Olefin polymer; Nanocomposite; Property structure relationship; Single screw extruder; Rheological properties; CRYSTALLIZATION; NANOPARTICLES; CLAY NANOCOMPOSITES; GAS BARRIER PROPERTIES; POLYMER; SILANE-GRAFTED POLYPROPYLENE; COMPOSITES; MECHANICAL-PROPERTIES; BLENDS; CARBON NANOTUBES
• ISSN: 0032-3888; 1548-2634
• DOI: 10.1002/pen.23768

Polypropylene/fumed hydrophilic silica nanocomposites were prepared via melt mixing method using a single‐screw extruder. Comparative study with and without compatibilizing copolymer agent (maleic anhydride grafted polypropylene: PP‐g‐AM) was conducted. The obtained results were interpreted in terms of silica nanoparticle–silica nanoparticle and silica nanoparticle‐polymer interactions. These results have shown that the addition of nanofillers improves the properties of the nanocomposites. From transmission electron microscopy, it was found that agglomerations of silica particles into the PP matrix increased in average size with increasing silica contents, except in presence of the copolymer. Storage modulus values of the nanocomposites measured by dynamic mechanical thermal analysis were sensitive to the microstructure of the nanocomposites. Higher silica contents resulted in higher storage modulus, revealing that the material became stiffer. By adding the compatibilizer, a further increase of storage modulus was observed due to the finer dispersion of the filler in the matrix and the increased interfacial adhesion. Crystallization rates were found to increase with the increase of silica nanoparticles as well as PP‐g‐MA content. In addition, silica nanoparticles and the compatibilizing agent present centers of germination and nucleation of crystallites. Thus, the use of the coupling agent resulted in a further enhancement of mechanical properties of the nanocomposites due to the reduction of silica agglomeration. POLYM. ENG. SCI., 54:2187–2196, 2014. © 2013 Society of Plastics Engineers