Ultrasound assisted cyclic solid-state foaming for fabricating ultra-low density porous acrylonitrile–butadiene–styrene foams

In this research article, novel porous microcellular ABS foams were fabricated and subsequently investigated for their morphological attributes. Initial research focuses on developing ultra-low density closed cell foams through cyclic microcellular foaming process. First stage foaming process develops microcells which affect the second stage of the batch foaming process. Hence, the effect of repeated foaming process on foam density and its morphology are discussed. Subsequently, ultrasound excitations were utilized to rupture the closed cell walls, thereby developing porous structure. The combined cyclic solid-state foaming and ultrasound excitation provides a way to fabricate ultra-low density porous polymers.