The relaxation properties in the dilute-gas limit have been calculated by the classical trajectory (CT) method for a gas consisting of chain-like molecules that are rigid and interact through site-site Lennard-Jones 12-6 potentials. Results are reported for volume viscosity ηV, rotational collision number ζrot and the ratio of the rotational to self-diffusion coefficient Drot/D. The results indicate that the volume viscosity increases with temperature and decreases with chain length. The rotational relaxation of chains is efficient, as it takes of the order of 1.75-2.7 collisions to attain equilibrium. The rotational collision number is only weakly temperature dependent. © 2013 Elsevier B.V. All rights reserved.