A technique, employing samples in the form of tuning forks, to measure the mechanical properties of polymers is presented. Results for low density polyethylene, polypropylene, and polycarbonates are shown. A large transition is observed for polypropylene at approximately +lO°C and a small transition
Dynamic mechanical properties of elastin
✍ Scribed by John M. Gosline; Christopher J. French
- Publisher
- Wiley (John Wiley & Sons)
- Year
- 1979
- Tongue
- English
- Weight
- 719 KB
- Volume
- 18
- Category
- Article
- ISSN
- 0006-3525
No coin nor oath required. For personal study only.
✦ Synopsis
Abstract
The dynamic mechanical properties of water‐swollen elastin under physiological conditions have been investigated. When elastin is tested as a colsed, fixed‐volume system, mechanical data could be temperature shifted to produce master curves. Master curves for elastin hydrated at 36°C (water content, 0.46 g water/g protein) and 55°C (water content, 0.41 g/g) were constructed, and in both cases elastin goes through a glass transition, with the glass transition temperatures of ‐46 and ‐21°C, respectively. Temperature shift data used to construct the master curves follow the WLF equation, and the glass transition appears to be characteristic of an amorphous, random‐polymer network. For elastin tested as an open, variable‐volume system free to change its swollen volume as temperature is changed, dynamic mechanical properties appear to be virtually independent of temperature. No glass transition is observed because elastin swelling increases with decreased temperature, and the increase in water content shifts elastin away from its glass transition. It is suggested that the hydrophobic character of elastin, which gives rise to the unusual swelling properties of elastin, evolved to provide a temperature‐independent elastomer for the cold‐blooded, lower vertebrates.
📜 SIMILAR VOLUMES
A recently developed dynamic mechanical analysis technique was utilized to determine the setting rates of dental amalgams. Via a compound parallel beam apparatus the dynamic mechanical properties of five amalgam materials were continuously measured at 37°C within ca. 7 min after the start of tritura
## Abstract We have investigated the effects of changes in solution composition on the mechanical properties of rings of arterial elastin. The time course of force equilibration at constant strain following a change in the composition of the bathing solution was measured. Both the force developed d