Modelling the large strain solid phase deformation behaviour of polymer nanoclay composites

• Published in: Mechanics of time-dependent materials 2008-12, Vol.12 (4), p.313-327
• Main Authors: Spencer, P. E., Spares, R., Sweeney, J., Coates, P. D.
• Format: Article
• Language: English
• Subjects: Applied sciences; Characterization and Evaluation of Materials; Classical Mechanics; Composites; Engineering; Exact sciences and technology; Forms of application and semi-finished materials; Fundamental areas of phenomenology (including applications); Inelasticity (thermoplasticity, viscoplasticity...); Physics; Polymer industry, paints, wood; Polymer Sciences; Solid Mechanics; Structural and continuum mechanics; Technology of polymers
• ISSN: 1385-2000; 1573-2738
• DOI: 10.1007/s11043-008-9064-7

This work concerns the solid phase deformation processing of polypropylene/nanoclay composites, for which the materials are stretched to large tensile deformations at elevated temperatures. Under these conditions the polymer matrix is nonlinearly dependent on time and strain rate. A constitutive model that is a combination of an Eyring process and physically-based molecular chain models has been shown to give a good representation of the polymer behavior, which includes strain-rate dependent yielding and stress relaxation. In order to model the nanocomposite, platelike regions that are relatively stiff are introduced into a continuum of model polymer material. This is done using a Monte Carlo approach that sequentially places non-overlapping platelets in the matrix. The process for introducing the platelets has the potential to produce platelet orientation distributions that conform with prescribed statistics, such as may be deduced from observations on real nanocomposite.