Relationship of Bita Characteristics to Liner Properties,
Abstract
Many of the linear systems used by the solid propellant rocket industry for HTPB propellants contain BITA (Trimesoyl-l(2-ethyl)aziridine) as a bond enhancer. This work demonstrates that liner-propellant bonds, liner viscosities, and rheological properties correlate with the polymeric content of the BITA. Purifying BITA to reduce the polymer content produces improved bonds and better control of linear viscosity. BITA monomer is relatively stable in the liner at cure temperature, but it reacts rapidly in the presence of AP in the propellant. The presence of BITA in propellant increases propellant maximum stress and also slightly accelerates the polymer-IPDI curing reaction rate, suggesting how BITA acts as a bond promotor by reinforcing the propellant at the interface. Several impurities were found by HPLC to be present in the commercial BITA. Undoubtedly some of these impurities are the polymeric species, but were not identified. However, only the peak attributed to the BITA monomer correlated with liner properties. Rearrangement of BITA aziridine functional groups to oxazoline structures does occur and was verified in this study, however, it did not correlate with linear properties. (Author)
Document Details
- Document Type
- Technical Report
- Publication Date
- Jan 01, 1985
- Accession Number
- ADP004990
Entities
People
- R. D. Law
- R. R. Hendrickson