Abstract
The experimental study of effects of heat on mechanical properties of Saran, is performed by using the strain meter.
The results obtained are as follows:
1. Stress-strain curves at different temperatures (30°, 60°, 90°, 120°C) have simple shape and they represent the maximum difference of tangent at between 30° and 60°C.
2. Young's modulus-temperature curve of Saran changes its curvature at the same temperature range.
3. Stress-temperature relation has the same tendency as that of acetate rayon at temperature range of 20_??_120°C, and that maximum shrinkage of the first cycle by heating is observed at same temperature (about 60°C) as that of large decrease of stress.
4. Reduced stress relaxation curves of Saran at 30°C show no change by variation of strain (5, 10 and 15%)
The relaxation curves at 60°, 90° and 120°C have similar behavior, but their stress decreases more rapidly than at 30°C.
5. Amorphous state of Saran is obtained by fusing and then rapidly cooling it in liquid oxygen. By changing the temperature and time different amounts of crystalline are produced. Their stress changes by drawing are larger at higher temperatute.
