Synthesis and Characterization of Ethylene Carbonate Derivatives and Their Effects on Properties of Polyurethane Hot-Melt Adhesives

1,2-Ethyl dihydroxyethyl urethane ester(EDHU)and 1,6-hexa dihydroxyethyl urethane ester(HDHU) were synthesized by the reaction of ethylene carbonate(EC) with ethylene diamine and hexamethylene diamine respectively. Structures of EDHU and HDHU were characterized by FT-IR,¹H-NMR and¹³C-NMR. They were used as chain extenders to react with diisocyanate(MDI)and polyester diols to get the polyurethane hot-melt adhesives.The adhesive,crystal,micro-phase separation,surface force and rheological properties were studied. The results showed that the micro-phase separation achieved to 91.2% and 83.9%, respectively, with EDHU and HDHU as chain extenders. Compared with the traditional polyurethane hot-melt adhesive extended by 1,4-butylene diol(BDO), the adhesive strength increased by 20% when extended by EDHU.