Mechanical properties of rigid thermoplastic foams—Part II: Stiffness and strength data for modified polyphenylene oxide foams

The through‐thickness variation in the porosity of structural foam material is known to result in different “material properties” when mechanics based on homogeneous materials is used to interpret data from standard tensile and bend tests. Procedures for determining the mechanical properties of rigid thermoplastic structural foams and for the application of these properties to the design of load‐bearing components were developed in a companion paper. This paper reports the mechanical properties of modified polyphenylene oxide foams, such as elastic moduli, ultimate stress and strain, as determined by tests on specimens cut from large, edge‐gated foam plates. Tests were conducted to study plate‐to‐plate variations in properties and to evaluate the effect of specimen thickness. Correlations of tensile and flexural data with the average specimen density are also discussed.