Elastomeric epoxy nanocomposites: Nanostructure and properties

• Published in: Composites science and technology 2012-03, Vol.72 (5), p.640-646
• Main Authors: Lipinska, M., Hutchinson, J.M.
• Format: Article
• Language: English
• Subjects: A. Nanoclays; A. Nanocomposites; Applied sciences; B. Mechanical properties; Clay (material); Composites; D. Transmission electron microscopy (TEM); Diamines; Dispersions; Elastomers; Enginyeria dels materials; Exact sciences and technology; Exfoliation; Forms of application and semi-finished materials; Homogeneity; Microscòpia electrònica de transmissió; Nanocomposites; Nanocomposites (Materials); Nanocompòsits (Materials); Nanomaterials; Nanostructure; Polymer industry, paints, wood; Propietats mecàniques; Technology of polymers; Transmission electron microscopy; Àrees temàtiques de la UPC
• ISSN: 0266-3538; 1879-1050
• DOI: 10.1016/j.compscitech.2012.01.012

In polymer layered silicate nanocomposites, significant differences have been reported between the effects of the nano-reinforcement on rigid and elastomeric nanocomposites. In this paper, we have studied elastomeric nanocomposites based upon DGEBA epoxy resin filled with montmorillonite (MMT) and cured with a long-chain polyoxypropylene diamine, for comparison with analogous rigid nanocomposites. Ultrasonic mixing was used to disperse the MMT in the matrix to improve homogeneity and decrease the agglomerate size. Two different methods of nanocomposite preparation were used in which the MMT was first swollen with either the curing agent or the epoxy before the addition of, respectively, DGEBA or diamine. A better dispersion of the nanoclay in the matrix and a greater amount of intercalation occurred when the MMT was first swollen with the diamine. The effect of MMT concentrations up to 8wt.% on the mechanical behaviour of the epoxy/MMT nanocomposites was investigated. It was found that the addition of MMT increased the tensile strength and modulus, although SAXS and TEM indicated that a significant fraction of the clay layers were not exfoliated. Nevertheless, the addition of the clay resulted in changes in the fracture surfaces, as indicated by SEM, consistent with the tensile results and indicative of toughening.