Theory of Dilute High-Polymer Solutions (the Pearl Necklace Model)

Abstract

A theoretical expression for the second virial coefficient A₂ of chain polymer solutions is derived. This accounts for the empirical relation between A₂ and molecular weight M, according to which A₂ is proportional to M^—α. α has a value of about 0.23 over a suitable range of molecular weight. According to the theory, α≈½—¾· (log1.684x), when x, a variable proportional to the square root of M, becomes very large. The temperature variation of A₂ is also explained. Krigbaum and Flory's data on the molecular weight and temperature dependence of A₂ are discussed.