Photo-responsive and color changeable embedded in aliphatic polyurethane

Abstract

Nowaday, the trend of smart and functional materials is wildly interested as new solutions for modern urban lifestyle. The material that can reversible change its color after inducing with sun light energy is also interesting topic. The light responsive transparent and high abrasive resistance aliphatic polyurethane was successfully prepared by the appropriate combination of rigid polymer, flexible polymers and aliphatic polyisocyanate. The sensitivity (speed of color changing), fatigue resistance and color strength (maximum absorbance) were monitored as evaluation criteria for light responsive efficiency and usable lifetime. The test specimens were prepared by coating the mixed solution on transparent polycarbonate substrate using spinning coat technique. At appropriate ratio between flexible and rigid polymers (0.1 – 0.3) resulted highly transparency film with can suddenly change its color under UV exposure. The fastest sensitivity is shorter than 5 sec. The color cans reversible immediately (shorter than 6 sec) after cut-off UV light source. The color strength and sensitivity of resulting mixed formulations were enhanced by synergistic combination between two species of photochromic color compounds. The light stabilizer additive specie was added in order to extent the usable life time (fatigue resistance) and weathering resistance property of final formulation.

Keywords: Photo-responsive materials, light responsibe materials, color changeable dye, polyurethane