On the use of a syntactic foam as core for sandwich panels and as external coating for pressurised pipelines

This work reports the main results of an experimental and numerical investigation on the mechanical properties and possible engineering applications of a syntactic foam. This foam consists of an epoxy resin matrix embedding randomly dispersed hollow glass microspheres made with a borosilicate glass; they present an average diameter of 70 μm and a wall thickness of 0.58 μm. To characterise this material, an extensive experimental programme has been carried out. The purpose of this paper is twofold: first, part of the experimental results obtained are briefly presented; second, two possible uses of the syntactic foam are discussed. In the first case the foam is used as the core of a composite sandwich conceived as a lightweight material for naval engineering applications; in the second case, the syntactic foam is employed as external coating of steel pipelines which are laid on the sea bed for pressurised oil transmission. This second application is explored due to the fact that the syntactic foam displays good mechanical properties and is at the same time a good thermal insulator.