Page 261 - Engineering Plastics Handbook

Thermoplastic Polyimide (TPI) 223

O O
C O C
O N N
C C
n−1 O O
m
(a)

Effect of chain length of ether diamine on T g
700
600 Polyimide from para-amino substituted diamine
500
Tg (°F) 400
300
200
Polyimide from meta-amino substituted diamine
100
0
0 1 2 3 4 5
Number of benzenes in diamine
(b)
Figure10.2 Effect of chain length of ether diamine on T g .

TABLE 10.1 Melt-Flow Start Temperatures of Polyimides and Their Structures
Melt-flow
start temperature, °F
Diamine Dianhydride
Amino-substituted Number of
position benzene rings Structure PMDA BPDA ODPA
Para 1 1a NF NF NF
2 2a NF NF 680
3a NF NF 806
3 3b NF NF 653
4 4a–p NF — 635
4b–p NF 806 —
Meta 1 1b NF NF NF
2 2c NF 590 536
3 3c — 734 608
3d 599 545 428
4 4a–m 500 518 473
4b–m 725 572 518
4c–m 626 572 527
4d–m 509 491 455
4e–m 536 527 482
4f–m 653 — —
4g–m 716 477 491