Hyderabad: The Advanced Centre of Research in High Energy Materials (ACRHEM) -- a DRDO Centre of Excellence in University of Hyderabad -- has been granted a patent for a process that finds major application in aerospace engineering and other areas.

The process patented under the title ''Hydroxyl Terminated Polybutadiene (HTPB) based Polyurethanes'' is the invention of Prof Tushar Jana and his associates, Dr. Bikash Kumar Sikdar and Moumita Dhara. Prof Jana belongs to the School of Chemistry, UoH, as well as adjunct faculty in ACRHEM.

Hydroxyl-terminated polybutadiene (HTPB) is a viscous liquid that has several uses. Its most important application is in solid rocket propellant (SRP) where it binds the oxidising agent and other ingredients into a solid but elastic mass.

The present invention describes a process for the tethering of energetic molecules or nitrogen-rich molecules at the terminal end of HTPB, which has resulted in an energetic HTPB binder, and also imparted superior properties than the native HTPB.

HTPB is an inert prepolymer that contributes nearly 10-15% mass of the propellant compositions; replacing the inert mass by energetic molecules and retaining inherent properties is a very crucial step to obtain an energetic binder.

Speaking to IANS, Prof. Jana said, "We have shown a new process, what we call a synthetic method in which we showed that we do not actually change any of the properties of the HTBP. As a result we will not disturb any of the properties of the propellant which we make. We are able to produce a more energetic fluid which actually gives more energy to the system."

Indian Space Research Organisation (ISRO), DRDO and various space and defence agencies across the globe employ HTPB-based binder to manufacture composite propellant systems. The inventors believe that the binder material described in this invention has very strong potential to replace the traditionally used HTPB binder in the manufacturing of solid rocket propellant.

The invention also reveals a synthetic methodology for the preparation of polyurethane (PU) with significantly high tensile properties from HTPB and various isocyanates. This will be of great help in manufacturing flexible polyurethane (PU) rubber with specific physical properties for various high-end applications such as aerospace engineering, surface coatings and surface sealants, high-performance adhesives, synthetic fibres and carpet underlay, and hard-plastic parts.