Synthesize, Characterization And Application Of Tea Polephenols-Rare Earth Complexes

In this paper, the tea polyhenols-rare earth(TP-RE) compounds were synthesized and characterized, for the more, their applications were studied. The result indicates that the TP-RE compounds have anti-bacteria effect which decreases obviously. The anti-oxygenation effect of TP-RE compounds is better than that of tea polyphenols,At first, the TP-RE compounds were synthesized in water solution via pure tea polyhenols (TP) and RE(La, Ce, Pr) chloride. The TP-RE compounds were characterized by IR, UV-Vis, TEM, SEM, EDX and fluorescence spectrum ect. The result shows that TP ligands with RE³⁺ ions through the ester carbonyl and phenolic hydroxyl. The UV-Vis spectrum of TP and TP-RE are different. The UV -Vis region of TP-RE is wider than TP, which indicates the better antioxidative effect. The fluorescence spectrums of all compounds are similar except TP-La compound . The fluorescence intensity of TP-RE compounds is weaker than that of TP and RE(La, Ce, Pr) chloride.The second, TP was extracted by microwave. The optimum conditions gained by the orthogonal test. In order to reduce the cost, the TP-La compound was synthesized directly using TP extract coming form above-mentioned. According to IR, UV-Vis, TEM , the products prepared from different TP are similar in structure and properties.LDPE film and PU film with TP-RE or TP were made. The result of weathering experiment shows that the anti-oxygenation effect of LDPE and PU film with TP-RE is better than that with TP.The anti-bacteria function of TP-RE and TP was studied by the methods of bacteriostatic circle and turbidimetry. The results show that TP-RE can inhibit E. coli and S. aureus. They even show that the higher concentrations of TP-RE, the better anti-bacteria function of TP-RE. Their anti-bacteria effect sequence is: TP>TP- Re> TP-Ce>TP- La>TP-Pr.