Molecular characterization of hydroxyl-terminated polybutadienes

A comparative study has been made on the functionality distribution of two hydroxyl terminated polybutadiene products which are used largely as prepolymers for sealants, adhesives, and solid propellants. They are known to possess nearly the same molecular characteristics. To this end, each product was fractionated into 17 fractions with different molecular weights by the preparative GPC technique. Sample fractions thus obtained were subjected to “polarity-controlled adsorption” thin-layer chromatography (TLC) to determine the functionality distribution. From these experimental results it was concluded that a decisive difference between these products consists in the functionality distribution, within a molecular weight range higher than 7000.