• M.Vinaya Babu
• Harish B Mallur
• Gagan G K
• Robinson P

This report focuses on the manufacturing of microcellular polycarbonate (PC) foams with bi- modal cell size distributions using carbon dioxide (CO2) as a blowing agent through solid state batch foaming technology. The sorption and desorption behaviours of CO2 in polycarbonate for various pressures were investigated. The effects of processing parameters such as foaming temperature, foaming time and saturation pressure on relative foam density, cell sizes and cell densities of the bi-modal foams were discussed in detail. The glass transition temperature (Tg) of the polymer/gas blend was found to a decent linear association with the absorbed carbon dioxide, and foaming takes above Tg of the polymer/gas blend. For manufacture of bi-modal polycarbonate foams, a two-step batch depressurization process is used which produces both small and large cells, which exhibit good improved properties compared to unimodal foams.

Polymer, Bimodal cellular structure, Polycarbonate, solid-state batch foaming, two step depressurization process

"BI-MODAL MICROCELLULAR MORPHOLOGY EVALUATON IN POLYCARBONATE FOAMS DEVELOPED USING TWO-STEP DEPRESSURIZATION FOAMING PROCESS", International Journal of Emerging Technologies and Innovative Research (www.jetir.org), ISSN:2349-5162, Vol.6, Issue 5, page no.500-507, May-2019, Available :http://www.jetir.org/papers/JETIRBZ06078.pdf

"BI-MODAL MICROCELLULAR MORPHOLOGY EVALUATON IN POLYCARBONATE FOAMS DEVELOPED USING TWO-STEP DEPRESSURIZATION FOAMING PROCESS", International Journal of Emerging Technologies and Innovative Research (www.jetir.org | UGC and issn Approved), ISSN:2349-5162, Vol.6, Issue 5, page no. pp500-507, May-2019, Available at : http://www.jetir.org/papers/JETIRBZ06078.pdf