Synthesis and properties of aqueous cyclic carbonate dispersion and non-isocyanate polyurethanes under atmospheric pressure

Cyclic carbonates (TMC/PMDC/BTDC) were synthesized at atmospheric pressure by glycerine carbonate (GC) reacting with trimellitic anhydride (TMA) / pyromellitic anhydride (PMDA) / benzophenone-3,3',4,4'-tetra-carboxylicdianhydride (BTDA). H-1 NMR spectra showed that the cyclic carbonates have 2.62, 3.72 and 3.43 cyclic carbonate functionality, respectively. TMC/PMDC/BTDC were further neutralized by dimethylethanola-mine and dispersed in water to prepare TMC/PMDC/BTDC aqueous cyclic carbonate dispersion. They exhibited no stratification after 5000 r/min centrifugation for 60 min, indicating their good stability. The particle sizes of these dispersions ranged from 30 to 120 nm with the Zeta potential from -55 to -79.5 mV. A series of waterborne non-isocyanate polyurethane (T-WNIPU, P-WNIPU and B-WNIPU) coatings were successfully prepared by reacting TMC/PMDC/BTDC cyclic carbonate aqueous dispersion with diamines. The WNIPU coatings all displayed excellent chemical resistance to toluene, xylene, alcohol and 5% H2SO4 as well as high gloss, impact resistance, adhesion, flexibility and hardness. The T(g )of WNIPUs was in the range of 31.4 degrees C-100.2 degrees C. All the WNIPUs coatings have good thermal stability with 5% weight loss temperatures (T-5%) above 242 degrees C.