Abstract

Polyurethane- polyurea hybrid spray coating was prepared by two steps polymerization. In the first step, polyurethane prepolymers (PUs) were prepared by polyaddition reaction based on 4,4-methylene diphebyl dissocyanate (4,4 MDI), poly(oxytetramethylene) glycol (PTMG), polyoxypropylene glycol (PPG), and triol (trade name FA-703) with different NCO/OH molar ratios. IR spectroscopy and acid-base titration were used to check the NCO content of the prepolymers. In the second step, polyurethane-polyurea hybrid resin was prepared by mixing the polyurethane prepolymer (PU) with polyoxypropylenediamine (POPA) at constant molar ratio (1: 1). The effect of NCO/OH ratios on physico-mechanical properties of the polyurethane-polyurea hybrid coating films was studied including viscosity, tensile strength, elongation at break, tear strength, contact angle and adhesion. The results obtained showed that tensile strength, contact angle and hardness increased, while viscosity, elongation, adhesion and tear strength decreased with increasing NCO/OH molar ratio.

Talk to us

Join us for a 30 min session where you can share your feedback and ask us any queries you have

Schedule a call

Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.