Polyurethane Foams for Methylene Blue Removal: Effect of Water Content

Abstract

In this study, polyurethane foams (PUF) with different water content (0, 2.5% and 5%) are ‎manufactured using polyester resin and methylene diphenyl diisocyanate through a one-shot bulk polymerization. The impact of water content on the chemical reaction rate, morphology,  and dye removal behavior of PUFs are examined using atomic force microscopy ‎‎(AFM), optical microscopy, open-cell content, and‏ ‏ dye adsorption analysis. The results reveal that the increase of the water content from 0 to 5% leads to the lower chemical reaction rates and increase of the cell size (56.6%), cell size distribution, open-cell content (96.5%), cell wall roughness (86.6%), and dye removal efficiency (171.7%). the enhanced dye removal is associated to the increased roughness and open-cell content. Accordingly, PUFs with an optimal amount of roughness and drainage flow can be a ‎promising candidate for dye wastewater treatment.