Synthesis of Polylactide with Thiol End Groups

Abstract

Four synthetic routes to poly(L-lactide) with thiol end groups based on ring-opening polymerization of L-lactide (LA) catalysed with tin(II) 2-ethylhexanoate (Sn(Oct)2) are reported. The following alcohols were used as co-initiators of polymerization: 2-sulfanylethan-1-ol, 2-[(2,4-dinitrophenyl)sulfanyl]ethan-1-ol, 2-(tritylsulfanyl)ethan-1-ol and allyl alcohol. End groups introduced into polymers by co-initiators were transformed to thiol groups by a subsequent modification reaction. The efficiencies of the used synthetic methods were evaluated and discussed. The best results were obtained with co-initiator 2-(tritylsulfanyl)ethan-1-ol.