An AFM study of Poly(L-lactic acid) and Poly(D-lactic acid) macromolecules and their stereocomplexes at the solid-air interface

Ashok Narladkar (1) , Eric Balnois (1) , Yves Grohens (1)

1 LIMATB - Laboratoire d'Ingénierie des Matériaux de Bretagne

The self assembly of PLA enantiomers have been studied at the nanometer scale using atomic force microscopy. At first, the conformation of D and L PLA macromolecules in dilute regime and the initial state of aggregation of both enantiomers were successively observed and compared with the aggregation of PLLA/PDLA blends. Our results points out differences in the aggregates structure between the homo-aggregates of each enantiomers and the 3 Dimensional stereocomplexes formed with racemic mixture of D and L entities. On the one hand, D or L PLA chains, which adopt a rigid conformation in dilute regime, form gradually aggregates that tend to grow from a nucleation center. On the other hand, stereocomplexes have a non-compact structure and are elongated with height variations within the fibrils that support the side by side aggregation of D and L helical structures to form thicker fibrils.

Mots clés: AFM; aggregation; PLA; stereocomplexation

Domaines: Polymères

Ashok Narladkar, Eric Balnois, Yves Grohens. An AFM study of Poly(L-lactic acid) and Poly(D-lactic acid) macromolecules and their stereocomplexes at the solid-air interface. Macromolecular Symposia, 2006, 241 (1), pp.33-44. ⟨10.1002/masy.200650906⟩. ⟨hal-00495107⟩