A new equation of state in hole theory based on a modified Floryʹs combinatorial factor

To describe the behavior of liquid state by hole theory, Floryʹs combinatorial factor used in the partition function of the hole theory is modified in a general form by assuming that unit segment of chain molecule can occupy more than one unit cell or lattice. From this combinatorial factor and two kinds of free volume expressions, two equations of state are derived, and are used to calculate the PVT behaviors of 10 pure polymer melts to test these EOSʹs. Good agreements between the theory and experimental data are obtained.