The effect of TDI, PTMG and DMPA on the physico-mechanical properties of polyurethane dispersion containing aromatic isocyanate

Abstract

The present paper relates to environment-friendly polyurethane dispersion having a high solids content of polyurethane polymer based on aromatic isocyanate. A series of water dispersion polyurethanes (PUDs) were prepared by polyaddition reaction using toluene diisocyanate (TDI), poly(oxytetramethylene) glycol (PTMG), and dimethylolpropionic acid (DMPA). Physico-mechanical properties of PUDs were studied by average particle size, viscosity, contact angle, tensile strength and elongation. IR spectroscopy was used to check the end of polymerization reaction and characterization of polymer. Results revealed that tensile strength, tear strength, hardness, contact angle and viscosity increase with increase of the amount of TDI, PTMG and DMPA in the PUDs. Elongation at break and average particle size decrease with increase of TDI, PTMG and DMPA. The increase of physico-mechanical properties are attributable to the increase of free NCO content and hard segment in the prepolymer of high content of TDI, PTMG and DMPA.