Nigus Maregu Demewoz

Fabrication And Characterization Of Low-Density Nanocellular Foam Based On PMMA/TPU Blend

Abstract: In nanocellular foam production, achieving cellsizes less than100 nmwith relative densities less than0.25 is challenging. In this study, PMMA was blendedwith three different hardnessesof thermoplasticpolyurethanes(TPU) to study their effects on thecellular structure. The TPU was well dispersed in thePMMA matrix witha domain size of less than 300 nm.The PMMA/TPU blends were foamed with a two-stepfoaming process using CO2as the blowing agent. Theresults show that the hardness and viscosity of TPUcontrolled the nanostructure of the blend and affectedthe foam morphology.TheTPUwithhigh hardnessand viscosityproducedthe smallest domain size andthe highest cell density, resulting in a low relativedensity.This is the first report ofaspecial bouquetnanocellularstructure with an average cell size of lessthan 100 nm and a relative density of less than 0.2.

Biography: Mr.Nigus Maregu Demewoz is a Ph.D. candidate at the Department of Materials Science and Engineering at the National Taiwan University of Science of Technology, Taipei, Taiwan. Before becoming a student, Nigus Maregu had been worked as an Assistant Professor in the Department of Physics at the Wollo University, Dessie, Ethiopia. Mr. Nigus obtained his B.S. degree in Physics from Debre Berhan University, Ethiopia, in 2011. Then he was awarded an Ethiopian government scholarship and earned his MS.c in radiation physics from Mekelle University, Ethiopia, in 2013. Now he is working his Ph.D. on polymer nanocellular foam under the supervision of professor Shu-Kai Yeh.