Synthesis of Ethoxylated Urethane and Modification with Cetyl Alcohol as Thickener*

A suitable reaction system, and proper conditions were designed to produce desirable polyurethane base thickener with a calculated number average molecular weight. Initially an ethoxylated urethane prepolymer was synthesized by reaction of a polyethylene glycol (M„=6000) and dicyclohexylmethane diisocyanate using the step growth polymerization technique. Modification was carried out by reaction of cetyl alcohol with the resulting prepolymer . The synthesis of ethoxylated urethane was investigated by using FTIR . Also 1 H NMR was used for showing substituted hydrophobe parts . It was found that, the measured number average molecular weight of synthesized hydrophobically modified ethoxylated urethane (HEUR) was in agreement with the calculated M . The thickening efficiency of the modified ethoxylated urethane was compared with a similar unmodified urethane . It was concluded that, the efficiency of modified ethoxylated urethane is very high in comparison with the unmodified one, although the synthesis conditions were similar for both modified and unmodified urethanes.