Effect of Soy Protein on Kinetics of Polyurethane Formation

The polymerization reaction kinetics of biodegradable polyurethane extended with soy protein isolate (SPI) with dibutyltin dilaurate (DBTDL) as the curing catalyst was studied by means of non-isothermal differential scanning calorimetry (DSC). Model-free methods, Kissinger method and Ozawa method, were applied for analyzing the DSC data. The E-a and InA obtained from Kissinger method for catalyzed reaction between toluene diisocyanate (TDI) and Polyoxypropyleneglycol (PPG) are 60.80 kJ.mol(-1) and 12.09, and for catalyzed reaction among TDI, PPG, and SPI they were 65.91 kJ.mol(-1) and 14.04. Similarly the E-a obtained from Ozawa method for catalyzed reaction between TDI and PPG and catalyzed reaction among ID!, PPG, and SPI were 63.49 kJ.mol(-1) and 64.78 kJ.mol(-1), respectively. The results showed that, the incorporation of a small amount of SPI into polyurethane did not affect the reaction kinetic strongly, but increases the reaction activation energy E-a and InA.