The Advanced Centre of Research in High Energy Materials (ACRHEM) — a DRDO centre of excellence at the University of Hyderabad (UoH) — has been granted a patent for “Hydroxyl Terminated Polybutadiene (HTPB)-based Polyurethanes”.
HTPB is a viscous liquid with several uses, including in solid rocket propellant (SRP) where it binds the oxidising agent and other ingredients into a solid but elastic mass. It is an inert prepolymer contributing nearly 10-15% mass of the propellant compositions as it replaces the inert mass with energetic molecules yet retains inherent properties which is a very crucial step to obtain an energetic binder, said a press release.
The present invention describes a process for the tethering of energetic molecules (nitrogen rich molecules) at the terminal end of HTPB, which has resulted in an energetic HTPB binder, and has also imparted superior properties than the native HTPB.
Indian Space Research Organization, DRDO and various space and defence agencies across the globe employ HTPB-based binder to manufacture composite propellant systems, it said.
Inventors of this patent are Tushar Jana (School of Chemistry and adjunct faculty in ACRHEM), and two of his associates — post-doctoral fellow Bikash Kumar Sikder (ACRHEM) and research student Moumita Dhara (Ph.D. student in the School of Chemistry). They believe the binder material described in this invention has potential to replace the traditionally used HTPB binder in manufacturing of solid rocket propellant.
The new HTPB binder also reveals a synthetic methodology for preparation of polyurethane with significantly high tensile properties and will be of great help in manufacturing flexible rubber with specific physical properties for various high-end applications such as aerospace engineering, surface coatings and surface sealants, high-performance adhesives, synthetic fibers and carpet underlay, hard-plastic parts etc.
