Molecular aggregation and gelation in poly(γ-benzyl L-glutamate) solutions

Abstract

Poly(γ-benzyl L-glutamate) forms a thermoreversible gel in benzyl alcohol.The network comprises fairly crystalline fibrillar aggregates. There are two types of complex structures depending on the gelation temperature in which the interchain distances are independent of concentration and the volume fraction of polymer is roughly 0.77. The two complexes have different melting points in the range of 60-70°C, which are almost constant over a wide range of concentration. The gel rigidity depends on polymer concentration and molecular weight in the following way. There is a critical concentration, C0, around 0.5 wt%. For C>C0, the shear modulus is proportional to C1.3 and independent of molecular weight. For C