Synthesis and characterization of novel vinyl polymers containing thioester group in side chain

Abstract

There have been many reports on the synthesis of macromonomers using thiols such as 3-mercaptopropionic acid (3-MPA). Star-shaped polymers containing sulfur were prepared by the radical polymerizations of macromonomers, and properties for paints were studied. Mercapto-modified polymers were highly adsorptive against heavy metal ions and useful for chain transfer agents of the radical polymerization to synthesize graft copolymers. The substituted allylic sulfides obtained from thiols as chain transfer agents in the radical polymerization gave end-functional polymers of controlled molecular weight. From this point of view, thiols such as 3-MPA are very often utilized for polymerization retarders and regulators in the field of macromolecules. The objective of our studies was to search for effective and wide applications of thiols such as 3-MPA, except for the application for polymerization retarder and regulator. We previously reported on the synthesis and characterization of the polymers containing sulfur in the main chain using 3-MPA. It is difficult to synthesize vinyl compounds from thiols because addition reactions of thiols to olefins occur easily. Otsu et al. reported on the polymerization reactivities of alkyl thioacrylate. In this study we synthesized and polymerized the novel vinyl monomers methoxycarbonylethyl thioacrylate (MTA), methoxycarbonylethyl thiomethacrylate (MTM), and menthoxycarbonylethyl thiomethacrylate (MnTM), which had a thioester group in the side chain, from 3-MPA and methyl 3-mercaptopropionate (M3-MP). The monomers were homopolymerized and copolymerizationed with styrene (St), methyl methacrylate (MMA), or N-cyclohexyl maleimide (CHMI). The characterizations of the polymers are examined.