THE CRITICAL CONSTANTS OF NORMAL ALKANES FROM METHANE TO POLYETHYLENE.2. APPLICATION OF THE FLORY THEORY

This paper examines the latest recommendations by Ambrose (on behalf o f IUPAC) for the critical constants of normal alkanes, with the primar y goal of extrapolating to very large normal alkanes such as linear po lyethylene. The Flory theory has been modified slightly and applied to the correlation of the critical constants. The theory treats all thre e critical constants on an internally-consistent basis, which is a cle ar theoretical advance relative to previous work. Inclusion of the cha in-length variation in the critical properties of normal alkanes makes it possible to establish the limiting values for critical temperature , pressure, and density. These limiting values are more credible than those predicted by ''power'' or ''exponential'' laws, which lack theor etical foundation and may be unsuitable for extrapolation.