A novel fluorinated diamine as an extender for polyurethanes

A novel environmentally friendly fluorinated diamine N-[2-[(2-aminoethyl) amino]ethyl]-perfluoro-2,5-dimethyl-3,6-dioxa-nonanamide(FDETA) was synthesized for the first time based on diethylenetriamine and ethyl perfluoro-2,5-dimethyl-3,6-dioxa-nonanoate (FEt). It was characterized by means of Fourier transform infrared spectroscopy (FTIR), nuclear magnetic resonance (NMR) and mass spectroscopy (MS). Subsequently, fluorinated polyurethanes (FPUs) containing various amounts of FDETA were then synthesized using hexamethylene diisocyanate (HDI), poly(tetramethylene oxide glycol) (PTMG), FDETA and 1,4-butanediol (BDO) as the main starting materials. Results of proton 1 H NMR and FTIR had verified successful incorporation of the FDETA chain extenders into FPU backbones. The surface properties of FPUs were detected by contact angle measurement, scanning electron microscope (SEM), and energy-dispersive X-ray spectroscopy (EDX). The thermal property of FPUs was also investigated by differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA). Results from EDX, SEM and contact angle studies indicated that fluorinated side chains in the hard segments had indeed migrated onto the surface. Results from DSC and TGA studies indicated that the thermal stability and the degree of phase separation were also improved.