Wx. Huang et Sl. Wunder, FTIR INVESTIGATION OF CROSS-LINKING AND ISOMERIZATION-REACTIONS OF ACETYLENE-TERMINATED POLYIMIDE AND POLYISOIMIDE OLIGOMERS, Journal of polymer science. Part B, Polymer physics, 32(12), 1994, pp. 2005-2017
The interrelationship between the cross-linking and isoimide-imide iso
merization reactions of oligomeric isoimides and imides was investigat
ed using FTIR spectroscopy. It was found that cross-linking of the ace
tylene units of Thermid IP-600 retarded the local rearrangement of the
isoimide to imide conversion of Thermid IP-600 compared with an anili
ne-terminated analog, decreasing the rate constant by a factor of abou
t 2. The increased flexibility of both the isoimide (Thermid IP-600) a
nd imide (Thermid FA-700) oligomers increased the cross-linking rate o
f the acetylene end groups by a factor of 4 and 2, respectively, over
that of the more rigid imide oligomer (MC-600). With increasing conver
sion of the isoimide to imide linkages in Thermid IP-600, the kinetic
parameters, E(a) and ln A, for the cross-linking reaction of this olig
omer became the same as those for the oligomeric imide, Thermid MC-600
. (c) 1994 John Wiley & Sons, Inc.