radicals under UV irradiation. Second, the radicals extracted hydrogen from the hydroxyl group of the active ingredients in MB to form alkoxy radicals on the substrate. Then the monomer molecules became acceptor of the radicals, resulting in chain initiation and thereafter themselves became free radical donors to neighboring molecules, which led to the growth of polymer chains. Finally, the end vinyl groups of the cross-linker (MBA) reacted with the polymer chains during chain propagation. In this way a cross-linked structure combined with network structure was formed gradually.27 Characterization of Materials. Elemental Analysis. Elemental analysis of MB, PAA, and MB−PAA is shown in Table 1. Compared with PAA, C content in MB−PAA