The molecular size distributions of poly (p-hydroxybenzoates)

briefly called PHB or PHBA

have been studied theoretically in this paper. It is impossible to investigate these distributions by experiments since no solvent for PHB has been found. As shown in the theoretical analysis

the molecular size distribution of PHB based on the polyconden-sation of phenyl p-hydroxybenzoate is slightly different from Flory distribution

by which that of PHBA obtained from p-hydroxybenzoic acid is characterized. This form of molecular size distribution for the former PHB can be regarded as a modified Flory distribution.