Journal of Applied Polymer Science, Vol.129, No.4, 1697-1706, 2013
Polyurethane-attapulgite porous material: Preparation, characterization, and application for dye adsorption
A series of polyurethaneattapulgite porous (HATT/PU) materials were prepared from polyether polyol (NJ-330), toluene diisocyanate (TDI), acid activated attapulgite (HATT), sodium bicarbonate as foaming agent, dibutylbis (lauroyloxy) tin (DBLT) as catalyst and silicon oil as stabilizer by foaming technique. The materials were characterized by FTIR, XRD and SEM. The polyurethaneattapulgite porous material as adsorbent was applied to malachite green (MG) dye wastewater treatment. Effects of attapulgite content, time, temperature, pH, and adsorbent dosage have been studied. The experimental results show that the maximum adsorption efficiency occurred at an attapulgite content of 6.0%, a time of 2.5 h, a temperature of 35 degrees C, a pH >5 and a HATT/PU dosage of 40 mg/mL. Equilibrium isotherms for the adsorption of the dye have been measured experimentally. Results were analyzed by the Freundlich and Langmuir equation and the characteristics parameters for each adsorption isotherm were determined: Gibb's free energy (G degrees), change in enthalpy (H degrees) and change in entropy (S degrees) have been calculated. The results indicated that the adsorption process was spontaneously an endothermic reaction and kinetically proceeded according to the pseudo-second-order model. The experimental results suggest that the prepared polyurethaneattapulgite porous materials have potential application for the wastewater treatment containing MG dye. (c) 2012 Wiley Periodicals, Inc.