Microcellular Foam Polymer Technology And Toughening Mechanism

In this paper, the influence of molding parameters on the mechanical properties of microcellular foam plastic (MCF) was studied at first. Accordingly, the best molding parameters of marking MCF by unclenching method were determined, and the MCF which has good combining mechanical properties was made. The theory of unclenching molding method of making MCF was studied.Another part of the paper, deformation and failure course of microcellular MCF have been observed in during tension and some microscopic observations for microcellular MCF after tensile loading is performed, from which the deformation morphology and failure mechanism of microcellular MCF are discussed. The impact experiments of microcellular PP with different gap have been done in different temperature and their impact properties are investigated. The impact and tensile surface morphologies of MCF are observed. The process of cells deformation and its effects on mechanical properties of MCF were studied. The toughing mechanism was studied.The results show that the density and tensile strength of MCF were reduced, the impact strength was increased. Cells were distorted with special aspect in the tensile process. The strut was broken down and cells were coalesced, which are the failure reasons. The impact strength of MCF is higher than solid materials, gap susceptivity lower and toughness in low temperature higher. The energy absorbed by four ways: the change and increase of crack expand route, the increase of resin deformation room, the form of sub creak and the change of failure mode.