The pair of stereoisomeric polyamides PA-6DAr and PA-6LAr, as well as the racemic stereocopolyamide PA-6DLAr was synthesized from hexamethylenediamine and 2,3,4-tri-O-methyl-arabinaric acid (D, L and their equimolar mixture, respectively). All these polyamides were aregic, thermally stable and display high crystallinity. The combined analysis by X-ray and electron diffraction revealed that the all three polyamides adopted the same crystal structure, which consists of a rhombic lattice with the chains in a highly contracted conformation capable of accommodating efficiently the sugar moiety in the space. The Avrami kinetic analysis revealed that copolyamide PA-6DLAr crystallized isothermally much slower than the optically homogeneous polyamides. A parallel study carried out on the racemic mixture of PA-6DAr and PA-6LAr evidenced that this mixture has a crystal structure and displays a thermal behavior similar to their separated components, and that its crystallization rate is intermediate between them and the racemic copolyamide PADLAr. (C) 2009 Elsevier Ltd. All rights reserved.