Page 238 - Engineering Plastics Handbook

204 Engineering Plastics

DMA: Log E ′ versus PPE/PA66 ratio
10 10
60/40
50/50
40/60
30/70
10 9 20/80
E ′, Pa 0/100
Log
10 8

10 7
25 75 125 175 225
Temperature, °C
Figure 9.5 Effect of PPE on storage modulus of PPE/PA66 alloys.

temperatures, improves dimensional stability, and lowers the density.
An example of the increased performance at elevated temperatures is
shown by dynamic mechanical analysis (DMA) in Fig. 9.5. In a series
of PA66/PPE alloys the storage modulus E′ increases as the PPE level
is increased. The effect of PPE lowering the moisture uptake is shown
in Fig. 9.6. Generally, as the PPE content is increased, the moisture
uptake is decreased.
In 1984 a unique family of PPE/PA alloys was commercialized under
the Noryl GTX trademark [24, 26]. Initially, PPE/PA resins were

Moisture uptake versus PA/PPE volume ratio
3
100/0
2.5 80/20
Weight increase, % 1.5 2 60/40
70/30

50/50
40/60

0.5 1 30/70

0
0 50 100 150 200 250 300 350
Time, h
Figure 9.6 Effect of PPE on moisture uptake in PPE/PA alloys.