Green polymer chemistry: Living oxidative polymerization of dithiols
Reduction sensitivity and mild synthetic conditions make disulfide-bonded materials ideal for degradable biomaterial applications. Both the degradation and the synthetic advantages of disulfide-bonded biomaterials have been applied to drug delivery vesicles, protein conjugation, and hydrogel biomaterials, but the synthetic advantages are rarely seen in the creation of biopolymers. A greener and highly efficient oxidative system is presented for the polymerization dithiols to high-molecular-weight poly(disulfide) polymers. The application of this system to 2-[2-(2-sulfanylethoxy)ethoxy]ethanethiol (DODT) produced corresponding degradable poly(disulfide) polymers with molecular weights as high as Mn = 250 000 g/mol and with a polydispersity index (PDI) as low as 1.15.