Solid Skin Characterization of PMMA/MAM Foams Fabricated by Gas Dissolution Foaming over a Range of Pressures

摘要

A new model for solid skin formation on submicrocellular foams based on PMMA is presented. Structural foams has been produced by the solid state foaming technique using as precursor material a blend of poly(methyl methacrylate) PMMA and a triblock copolymer [poly(methyl methacrylate)-block poly(butyl acrylate)-block poly(methyl methacrylate), MAM]. An analysis on the skin thickness and densification has been carried based on x-ray high resolution radiography. The obtained results have been related to the fabrication parameters, i.e. MAM content of the blend and foaming pressure, and provide us a new vision about the processes that control the formation of a solid unfoamed, or partially unfoamed, skin in these materials.