Many spacer-containing functional polymers were produced by
modifying beads of (vinyl)polystyrene,
as obtained by free-radical suspension polymerization of a commercial
55:45 divinylbenzene:ethylstyrene mixture, or from commercial sources. Thus, in the
presence of free-radical initiators,
compounds HBr, HPR2, HP(OR)2, and HSR (R =
various alkyl, aryl or acyl, some also containing
further COOH/R, OH/R, SH/R, N(H/R)2 groups) underwent
anti-Markovnikov addition to the
residual vinyl groups. Similar free-radical functionalization with
various HSiR3 also proved feasible
but more difficult. Other products corresponding to formal
anti-Markovnikov addition of H2S,
HSO3
-, HP(OH)2, H2,
HBR2, HOH, and HOSO2R were obtained by other
mechanisms, or after
further modifications. FTIR spectra of the resulting functional
polymers often showed complete
or near-complete disappearance of initial vinyl groups and their
replacement by the expected spacer-supported functionalities. The polymer products were also
characterized by elemental analysis
and solid-state NMR. Many of these functionalized beads, or their
further derivatives upon
functional group modification, could act as stable and effective
solid-phase reagents, catalysts,
sequestering agents, or protecting groups for solid-phase
synthesis.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.