New UV-absorbing Polymers Based On Ethyl Ferulate And Caffeic Acid Phenethyl Ester: Synthesis And Characterization

Hydroxycinnamic compounds are widely found in nature.These compounds can be extracted from many plants and animals and they are the important natural antioxidants.Ethyl 4-hydroxy-3-methoxycinnamate(ethyl ferulate,EF)is a natural ingredient with many excellent biological activities such as antioxidant and oxygen free radical scavenger.Caffeic acid phenethyl ester(caffeic acid phenethyl ester,CAPE)is an effective component of natural propolis,which has antioxidant,anti-inflammatory,antibacterial,and anti-tumor effects.The maximum UV absorption peaks for EF and CAPE are 319 nm and 323 nm respectively(UVA:320-400 nm,UVB:280-320 nm).The active ingredients in sunscreens currently on the market are mainly small molecular compounds that are resistant to UV radiation.Studies have shown that UVA and UVB ultraviolet radiation cause reactive oxygen species(ROS)on the surface of human skin.It destroys human cells and even genomic DNA.The small molecule active ingredients in sunscreens are also easily absorbed by human skin and cause toxic side effects to humans.Therefore,it is important to research the polymeric ultraviolet absorbent that can stably prevent UV-sunscreens penetration into the skin.Based on ethyl ferulate and caffeic acid phenylethyl ester,new polymerizable UV monomers capable of absorbing different wavelengths of ultraviolet light respectively were synthesized,and then these monomers were reacted with methyl methacrylate(MMA),and n-butyl methacrylate(BMA)to achieve their corresponding copolymers through living radical polymerization.The 1H NMR,FT-IR and GPC data shown that these new UV-absorbing monomers and polymers have been successfully achieved.Moreover,the UV-vis spectra confirmed that the UV absorption wavelengths of these polymers are in the range of 270 nm-330 nm,good as UV absorbers.In concluion,these newly prepared UV absorbing monomers and polymers are potentially useful in personal care applications,e.g.,UV sunscreens,cosmetic foundations.