Optimization of HTPB Binder
Abstract
The fractionation of R-45M hydroxyl terminated polybutadiene prepolymer is reported. Scale-up fractionation over silica gel was found to cause non-reproducible structural changes and thus was concluded to be impractical. Fractionation by solvent precipitation produced material having an average molecular weight of 2000 at average functionality of two, and trifunctional material of average molecular weight 6000. Cure studies suggest that the 2000 molecular weight fraction still contains some low molecular weight trifunctional material that effects crosslinking, and the resulting propellant was found to have poor tensile properties at -65 degree F. However, tear resistance at 70 degree F was improved. Temperature cycling capability of analog motors containing low molecular weight difunctional fractions was compared with those containing the parent R-45M. At approximately the same initial modulus at 70 degree F, the cycling behavior (-80 degree F to 160 degree F) of the two systems was not significantly different.
Document Details
- Document Type
- Technical Report
- Publication Date
- Jan 01, 1972
- Accession Number
- AD0892430
Entities
People
- A. H. Muenker
- B. E. Hudson
- C. Gustavson
- D. Grafstein
- G. E. Myers
- G. R. Cann
- W. E. Baumgartner
- W. E. Heikkila
- W. G. Stapleton
Organizations
- Lockheed Propulsion Company