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Thioamide groups were introduced into polystyrenes by the Friedel–Crafts reaction, with phenyl isothiocyanate in nitromethane solution, in the presence of anhydrous aluminium chloride. Free radical copolymerization of 4-vinyl dithiobenzoate with styrene followed by low-temperature solution condensation reactions, with excess of amines in N,N-dimethylformamide, offered another synthetic route to (co)polymers containing thioamine groups in the side chains without crosslinking. © 1998 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 36: 117–127, 1998

The syntheses and free-radical polymerizations of methyl and carboxymethyl 4-vinyldithiobenzoates are described as well as various copolymers. Copolymerisation parameters were determined for the copolymerizations of the methyl dithioester with styrene and with methyl methacrylate.

Dithiocarboxylic groups as side groups on linear or crosslinked polymers were transformed quantitatively into the corresponding thioamides by ammonia and primary or secondary amines, whereas reaction with 1,2-diaminoethane led to poly(Δ2-imidazoline)s. Due to the high reactivity of carboxymethyl diethioesters [(2-thioacylthio)acetic acid] the fixation of amino acids, dipeptides, and amino dyes on macromolecular chains was realized with high yields.

Dithioester groups were introduced into linear or crosslinked polystyrenes by Friedel-Crafts reaction with ClCH2Si(CH3)3/CS2 or with ethyl chlorodithioformate, as well as thioamide groups by reaction with ethoxycarbonyl isothiocyanate. Treatment of several copolymers of acrylonitrile with ethanethiol and hydrogen chloride and subsequently with H2S led to copolymers with dithioester and thioamide groups in the side chains without cyclization. Most of these reactions occur without crosslinking.