Natural pigment during flora leaf senescence and its application in dyeing and UV protection finish of silk and wool -- a case study of Cinnamomum Camphora

Flora forest is a major component that contribute to the natural resource in which natural pigment can be derived from. Tree leaves produce various pigments during leaf senescence. This study investigates natural pigment changes of Cinnamomum Camphora leaves at different life stages (young, mature, and old) and their applications in the dyeing and UV protection of silk and wool textile. It is shown that FTIR spectra can be used to assist the leaf pigment examination, and that the pigment of chlorophyll (from young leaves), anthocyanin (from mature leaves) and dark brown pigment (from old leaves) can be extracted effectively using ethanol, acid and alkaline. Both silk and wool showed excellent dyeing ability when dyed with the extracted pigments. Fabrics dyed with leaf pigments (except for the chlorophyll) showed an unchanged or increased colour fastness to light, wash and storage. This is because the rich content of phenolic hydroxyl within leaf chemical structure is sensitive to light and alkaline condition, and can result in a hyperchromic effect. All the fabrics dyed in this work showed an excellent UV protection performance compared with that of undyed.