Prevention Of Coloured Solid Surfaces By Incorporation Plant Extract

Abstract

  In this study, Cucurbita pepo fruit was extracted separately by three solvents including hexane, 70% methanol, and water, and tested for the antioxidant activity using DPPH. The results showed that the 70% methanol extract works as an antioxidant and has been underwent to chemical analysis and extracted subsequently by ethyl acetate. The ethyl acetate extract underwent a separation process and the higher activity compound was isolated to inhibit DPPH and characterized by IR, H-NMR, Mass spectra, the effective compound was suggested to be (quercetin-3-o-rhamnosyl(1 ?6) glucoside).The  paint nitrocellulose coloured (RED , yellow , blue ) was prepared with a concentration 20 ppm , modified   by incorporating isolated compound  as photostabilizer .Then, the modified coatings were used to coat glass slides samples in order to protect the from color fading  the action of artificial UV light.    During (0,10,20,30,40,50,60) min of irradiation of the glass slides coated the color degradation was measured and the results were studied using UV-Vis spectroscopy. Decolorization ratios were for slides coated with NC paint red, yellow and blue by 61.2% , 50.1% and 45.5% respectively, in the absence of the extract (isolated compound )and after one hours of irradiation with UV, while the Decolorization ratios  were 52.6% ,38.2% and 29.8% with  presence of  extract and this shows the role of the extract protecting the dyes photo fading when exposed to UV light. The results showed that among the most effective colors in Resistant to light fading was NC paint blue (PB15;6) compared to other NC paint colors.