Preparation And Application Of Functional Micro-cellular (Porous) Materials

The propylene-styrene-butadiene?ABS?cellular and porous materials were successfully prepared by the batch foaming process using super critical carbon dioxide or nitrogen?Super critical nitrogen,SC-N2;Super critical carbon dioxide,SC-CO₂?and etching method.The optical properties of the cellular materials,the conductive properties of cellular and porous material were studied.In this paper,microcellular acrylonitrile-butadiene-styrene?ABS?foam was prepared by supercritical N2 foaming technology.The influence of the different microcellular foaming process on the cell structure,uniformity,various physical properties and the optical properties of microcellular ABS foam were researched.The results show that the rise of saturation temperature will make cell size increase,cell density decrease,and the material mechanical property decrease slightly,the light transmittance slash,and haze increased significantly;Increase the saturation pressure,the size of cell first decrease and then increase,cell density increases,cell space distribution more uniform,when the cell size in 400-700 nm and cell density is 10²¹ cell/cm³,high light transmittance and haze can be obtained.The formation mechanism of nano-cellular structure and composite cell structure were analyzed by dynamic thermomechanical analysis,transmission and scanning electron microscopy.The results showed that there were obvious multi-level secondary relaxation and specific colonic structure in ABS.ABS micro phase separation of the microstructure was proved which directly led to the formation of nano-cellular and composite cell structure.The cell size and the cell density of ABS nanopores and microcellular materials were prepared by etching method.The results of scanning electron microscopy showed that the cell size gradually increased and the cell density decreased with the increase of PEO content.The ABS porous materials were prepared by supercritical CO₂ foaming method and etching method.The effect of PEO on the melt flow rate?MFR?of ABS was evaluated by the plastic flow rate tester.The results showed that the melt flow rate increased obviously and the MFR increased much more with high PEO content.The glass transition temperature?Tg?of the ABS/PEO blends were evaluated by differential scanning calorimetry.The results showed that the Tg shifted to the low temperature region and the higher the PEO content was,the higher the Tg was.The larger the Tg was observed by SEM.The results show that the pore structure of the perforated materials produced by the foaming method and the dissolution method is different,but the porosity of the pores is about 50%.The ABS conductive materials were prepared by foaming method and foaming following etching method.The resistivity and electrical conductivity of the materials were measured by a resistance meter.The results showed that the resistivity could be reduced to 0.6? · cm when the content of conductive carbon black is more than 6%,the resistance conductivity reduced to 2.92 S/m.When the content of conductive carbon black reaches 6%,the resistivity could be reduced greatly and the resistance conductivity isreduced to 0.5? · cm,the conductivity increased to3 S/m.