Crystallizable and Tough Aliphatic Thermoplastic Polyureas Synthesized through a Nonisocyanate Route

A simple nonisocyanate route for synthesizing crystallizable and tough aliphatic thermoplastic polyureas (TPUreas) is described. Melt transurethane polycondensation of diethylene glycol bis(3-aminopropyl) ether with bis(hydroxyethyl) hexanediurethane and bis(hydroxyethyl) isophoronediurethane was conducted at 170 degrees C under a reduced pressure of 3 mmHg, and a series of TPUreas were prepared. The TPUreas were characterized by GPC, FT-IR, H-1 NMR, C-13 NMR, 2D C-13-H-1 HSQC NMR, DEPT-135 C-13 NMR, DSC, TGA, wide-angle X-ray scattering, atomic force microscopy, and tensile tests. The TPUreas exhibited an M-n up to 12 000 g/mol, an M-w up to 17 600 g/mol, T-g between 2.8 and 18.1 degrees C, T-m from 140.5 to 149.8 degrees C, initial decomposition temperature of over 278.4 degrees C, and tensile strength up to 37.81 MPa with elongation at break of 691.25%. TPUreas with high T-m, good tensile strength, and good toughness were prepared through a nonisocyanate route.