Stereocomplexed Materials Based on Poly(3-hexylthiophene)-<i>b</i>-poly(lactide) Block Copolymers: Synthesis by Organic Catalysis, Thermal Properties, and Microscopic Morphology

Abstract

A new approach to control the supramolecular organization of conjugated polymers is proposed, based on stereocomplex formation. It is illustrated by mixing polymer solutions of block copolymers, i.e., poly(3-hexylthiophene)- b -poly( l -lactide) and poly(3-hexylthiophene)- b -poly( d -lactide). The block copolymers were successfully synthesized via a three-step procedure including the use of metal-free organic catalysts in the ring-opening polymerization of l - and d -lactide. The thermal properties and microscopic morphology of sterecomplexed diblock copolymers show that the stereocomplexation of the polylactide blocks is able to prevent the crystallization of the regioregular poly(3-hexylthiophene) block into long-range ordered parallel fibrillar structures. Stereocomplexation is also observed when mixing poly( d -lactide) homopolymer and poly(3-hexylthiophene)- b -poly( l -lactide) block copolymer.