Adhesion and tribological characteristics of modified polyurethane coating on composite substrate

ABSTRACTIn the present study, glass-epoxy composites were used as a substrate to study the performance of modified polyurethane coating. Two-layer coating (180–200 µm) wherein the epoxy primer as the first coat and polyurethane as the top coat was applied using an air-assisted spray gun to increase the service life of the composite. The analysis of coating was performed using gloss, contact angle, FTIR, TGA, tensile test and SEM. The bonding strength between coating and substrate was evaluated by cross-hatch cut, 180 deg peel strength and pull-off adhesion tests. Scratch, Taber abrasion and Pin-on-disc tests were also performed to evaluate the wear resistance. In addition, a rain erosion test was performed to check the stability of the coating. From the above tests, it is concluded that the applied coating well adhered to the composite substrate. The data generated from different tests can be used to estimate the service life of polymer composites and coatings.KEYWORDS: Polymer compositesepoxy coatingspolyurethane coatingsadhesion propertiescharacterization‌wearScratch testTensile test180 degree strengthRain erosion‌ AcknowledgementsThe authors gratefully acknowledge BITS Pilani Hyderabad Campus and thank CAL and Workshop Divisions, Chemical and Mechanical Engineering Departments. The authors thank Advanced Systems Laboratory (ASL), Defence Research and Development Organization for their financial support (Grant Number: ASL/31/20/4051/CARS/073). Also, the authors extend their appreciation to Mr. Karthik Reddy, Mr. C. Kaushik and Ms. Pallavi for giving their valuable insights and assistance during the experiments.Disclosure statementNo potential conflict of interest was reported by the author(s).Additional informationFundingThe authors (s) received financial support for the research from Advanced Systems Laboratory (ASL), Defence Research and Development Organization (Grant Number: ASL/31/20/4051/CARS/073)