Stiffness constants prediction of nanocomposites using a periodic 3D‐FEM model

Abstract

Predictive models, which enable the prediction of nanocomposite properties from their morphologies and account for polymer orientation, could greatly assist the exploitation of this new class of materials in more diversified and demanding market fields. This article focuses on the prediction of effective elastic properties (Young's moduli) of polymer nanocomposite films (copolyamide-6/nanoclay) using 3D analytical (based on the Mori-Tanaka theory) and 3D finite element (FE) models. The analytical model accounts for the orientation of polymer chains induced by drawing. 3D FE model exploits the representative volume element concept and accounts for the nanocomposite morphology as determined from transmission electron microscopy experiments. Model predictions were compared with experimental results obtained for nanocomposite films produced by means a pilot-scale film blowing equipment and collected at different draw ratios

Effect of biaxial drawing on morphology and properties of copolyamide nanocomposites produced by film blowing

“…TEM images at different magnifications were also used to evaluate empirically the average length-thickness ratio of silicate platelets-stacks and to compare with the aspect ratios based on the Nielsen model. The average aspect ratios obtained with the graphical approach [35] were 58 and 55 for the 3 wt.% hybrid films stretched, respectively, at BUR = 2.5 and DR = 23, and at BUR = 2.5 and DR = 35, higher than the values calculated by the Nielsen fit. This disparity can be explained in a number of ways.…”

Morphology Development and Mechanical Properties Variation during Cold-Drawing of Polyethylene-Clay Nanocomposite Fibers

“…Compared to the traditional filler-reinforced systems, the improved properties of polymer nanocomposites are mainly due to the stronger interfacial interaction that occurs between the polymer matrix and the silicate layers. Depending on nanocomposite morphology and clay loading, different effects on mechanical performances are reported in literature: low content and intercalated/exfoliated morphology lead to properties increase [ 9 , 22 , 23 ], while higher content and/or hybrid morphology (i.e., the presence of both tactoids and intercalated zones) produce no increase or a decrease of mechanical properties [ 24 , 25 ]. Moreover, the nano-platelets affect also rheological properties that are of widespread importance for process stability of polymeric systems.…”

Tuning of co‐extrusion processing conditions and film layout to optimize the performances of PA/PE multilayer nanocomposite films for food packaging

“…An organoclay content of 4 wt% was selected as it should provide the better performance improvements, avoiding the problem of filler riaggregation, as suggested by previous studies .…”

“…Significant progress has been made in analyzing the manifold relationships among system composition, processability, and morphology of polyamide–silicate nanocomposites . In particular, it was evidenced that the obtained properties improvement is strictly related to the adopted production technology and processing conditions , but despite the wide scientific literature devoted to the polyamide‐based nanocomposites, few investigations were carried out on multilayer systems for flexible film packaging applications . In this regard, it is worthy to point out that a monolayer polymer film—displaying a particular set of properties—may not display the same performances when that material is used as a layer in a coextruded structure because the layering process affects the system morphology (polymer orientation, bulk and interface crystallinity, etc.…”