“…The chitosan derivatives could be used as sunscreen because they had the UV-absorption groups (Juthathip, Mitsuru, Toshiyuki, & Suwabun, 2006;Renbutsu et al, 2008). Our research group previously reported the method of chitosan derivatives carrying the benzene group by Michael reaction (Ma, Qian, Yang, Hu, & Nie, 2010). Preparation of organic soluble chitosan derivatives can expand its application in many fields (Jeong et al, 2008;Ma et al, 2009;Wang et al, 2009;Zong et al, 2000).…”