Novel Macromolecular Structures and Composites.
Abstract
The Dynastat mechanical testing instrument purchased under the URIP Grant is now fully operational. It is presently being used to a large extent for research involving the Farris research group. The projects primarily influenced and which constitute about 90% of the time on the instrument are the AFML. Molecular Composites Program and a DoD LOVA program. The instrument is sufficiently versatile that it can be used for a multitude of materials and is especially useful for very stiff materials, a region where most instruments fail. As an example of the type of data that can be taken we have included some recent data. Figure 1 illustrates the in-phase modulus in uniaxial compression of a polyacetal-polyurethane thermoplastic elastomer as a function of frequency at several temperatures. Figure 2 shows the master curve for this material using the computerized timer-temperature/frequency-temperature shifted data. Also included in this figure are the reduced data at 40% and 60% filler content. Figure 3 shows the curing of a graphite-epoxy prepreg in shear during cure. In this experiment the sample is being increased in temperature linearly with time. The prepreg softens at about 50 C and little happens until 160 C where reaction commences, as illustrated by a drop in the loss factor and an increase in the stiffness. It is currently being used to develop a new Impulse Method of Viscoelastic characterization which related time-integrals of stress to time integrals of strain for pulse experiments.
Document Details
- Document Type
- Technical Report
- Publication Date
- Jun 01, 1985
- Accession Number
- ADA166243
Entities
People
- Frank E Karasz
Organizations
- University of Massachusetts Amherst