Materials Science & Engineering

Biography

Biography: Harshal D Santan

Abstract

In this work, we studied the effect of chemical modification of castor oil (CO) based polyurethane (PU) adhesives, once included bio and synthetic polymer on the adhesiveness. In detail, two different adhesives were prepared by chemical functionalization of castor oil by adding gelatin (0.5-1.5 wt%) and poly(ethylene oxide-b-propylene oxide-b-ethylene oxide) (PEPE) (5 and 10 wt%) using hexamenthylene diisocyanate (HMDI) as a crosslinker. These adhesives were cured at room temperature and the curing process was followed by using ATR-FT IR spectroscopy to check the presence of –NCO groups during the curing. In addition, the mechanical properties were anlalyzed by performing rheological measurements before and after curing of these adhesives. The adhesiveness of the system was measured by performing tack tests by using smooth plateplate geometries with different initial gap (0.1 and 0.5 mm) and by applying different debonding velocities (1 to 5 mm/sec) and then the adhesion energies were calculated. The chemical functionalization of CO-based adhesives by gelatin and PEPE has induced a dramatic enhancement in adhesivesness. Moreover, the gelatin based CO adhesives have shown highest adhesiveness due to the ability of gelatin to form triple helices, which can also contribute to enhance the adhesiveness. However, an excessive increase in the amount of geltin (>1.5 wt%) and PEPE (>10 wt%) in the composition, yields a decrease in adhesiveness. Thus, the adhesiveness of the system was tunable by varying the amount of gelatin and PEPE in the composition. Moreover, these adhesives were found to be degradable in presence of emzyme.