Functional Alkyl-Ferrocene Grafted Hydroxyl Terminated Polybutadiene

Abstract

Grafting of functional ferrocene molecules in the backbone of hydroxyl terminated polybutadiene (HTPB) without altering physical characteristics such as viscosity, hydroxyl value, molecular weight of the pristine HTPB remains as an important challenge owing to the difficulty in synthesizing appropriate functional ferrocene molecules and the suitable grafting methodology. The present report describes a facile and cost-effective process for the synthesis of thiol, silyl and halogen derivatives of alkyl-ferrocene. This process delineates the use of cyclic anhydrides as precursor for functionalizing ferrocene with terminal carboxylic acid in order to purify via acid-base workup. The synthetic process includes moderate reaction conditions with good to excellent yields. The ferrocene-alkyl-silane and ferrocene-alkyl-thiol are grafted covalently to the pendent vinylic groups of HTPB with unaltered physical characteristic in order to prepare polymeric binders with enhanced burn rate for the use in composite solid propellant for aerospace applications.