Final Report on Office of Naval Research Contract No. N00014-84-K-0508 with Lehigh University
Abstract
A group contribution theory was developed to describe the area under the loss modulus-temperature peak, LA, in the glass transition region of homopolymers and single-glass transition statistical copolymers and related compositions. Within wide limits, each chemical group on the polymer was found to contribute a definite proportion of the area. Groups directly associated with the backbone chain contribute the most to damping, while long side chains actually are detrimental. Deviations from this theory for multiphase morphologies were studied for IPN's and related compositions. It was discovered that some morphologies resulted in a significant increase in LA, thus increasing the efficiency for damping sound and vibrations. For high tan delta values, the continuous phase should be very soft, with a large amount of dispersed phase near the glass transition temperature. The basis for providing a systematic approach to superdamping materials was laid. (TTL)
Document Details
- Document Type
- Technical Report
- Publication Date
- Oct 14, 1990
- Accession Number
- ADA228589
Entities
People
- J. J. Fay
- M. C. Chang
Organizations
- Lehigh University