Optimization of Synthesis of Polyurethane Foam Prepared from Liquefied Corn Stover by Response Surface Methodology

Abstract

Polyurethane (PU) foam was prepared from no pretreated liquefied corn stover (LCS) and polymethylene polyphenylisocyanate (PAPI). Response surface methodology (RSM) was employed to model the co-polymerization of LCS and PAPI and to optimize the process conditions for the maximum tensile strength of polyurethane foams. A total number of 36 runs was carried out following a quadratic regression rotational combinational design in order to evaluate the effects and interaction effects of four variable parameters, namely [NCO]/ [OH] ratio, blowing agent (water) concentration, ratio between catalysts (triethylamine : dibutyltine dilaurate) and surfactant (silicone) concentration. The analysis of ANOVA of the quadratic orthogonal regression model revealed that the model has high significance. The maximum tensile strength of 1.64 MPa was obtained at the optimal conditions: [NCO]/ [OH] ratio 0.7, blowing agent concentration 4.7%, surfactant concentration 1.27% and the ratio between catalysts 1:1.