EQUATIONS OF STATE FOR HARD CHAIN MOLECULES

Equations of state for hard sphere chain molecules are derived within the framework of second order perturbation theory of polymerization (T PT2). The present formulation differs from the original Wertheim's tre atment by dealing with molecules with a fixed number of beads. However , the two versions yield very close numerical results for chains compo sed of freely jointed spheres, showing the insensitivity of the pressu re of these fluids to polydispersity. The case of star-like molecules and chain mixtures is also considered. Theoretical predictions are com pared to available simulation data, using recent results for the tripl et correlation function for hard spheres in rolling contact. Some pred ictions for the pressure of freely rotating chains and that of trimers as a function of the bond angle are given.