A new type of hydrophilic monomer N-(2-aminoethyl)-aminopropionate sodium (AAA-Na) was synthesized by the Michael addition reaction using ethylene diamine and methyl acrylate as raw materials.Polyurethane dispersions (PUDs) with solid content above 40% were synthesized by the acetone process using N-(2-aminoethyl)-aminopropionate sodium(AAA-Na) as hydrophilic monomer

poly(1

4- butanediol adipate) (PBA)

isophorone diisocyanate (IPDI)

ethylene diamine (EDA) and diethanolamine (DEA) as raw materials.The zeta potentials of PUDs were between -40 mV and -60 mV and displayed excellent stabilization.When hydrophilic group content (HGC) increased

average particle size decreased

particle size distributions narrowed and viscosity increased.TEM analysis showed spherical shapes of the particles with different sizes and multivariate distribution.Tensile stress of PUD films all exceeded 17 MPa

tensile strain was about 1400%

Shore hardness all exceeded 80 and water absorption was all under 10%.TGA showed that initial decomposition temperature of PUD films was about 270℃

and decomposition completed basically at 500℃.