Molecular weight : Property relationships of high performance polymers used for adhesives and composites
- Kranbuehl, D.
- Aug 31, 1975.
- Physical Description:
- 1 electronic document
- Restrictions on Access:
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- Degradation of high performance polyimide precursor resins was investigated by measuring the molecular weight of the polymers in solution, using a membrane osmometer. It was found that polyimide precursor resins composed of BTDA and ODPA combined with DABP and MDA were unstable in DMAC. The degradation rate was found to depend upon the chemical nature of the isomeric diamine and the geometric structure about the amide linkage. The polymers of DABP were less susceptible to degradation than those of MDA and p,p'-compounds were more stable than m,m'-compounds. These results suggest that degradation is correlated with the basicity of the diamine. That is, the rate of the degradation reaction increases with the basicity of the diamine group in the polyimide precursor resin. The presence of water and a higher temperature increased the degradation rate of the polymers.
- Other Subject(s):
- NASA Technical Reports Server (NTRS) Collection.
- Document ID: 19750024174.
Accession ID: 75N32247.
- No Copyright.
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