Yc. Ke et Zw. Wu, THE ABSORPTION BEHAVIOR AND CRYSTALLIZATION OF POLY(ARYL ETHER KETONE) FILMS, Journal of applied polymer science, 67(12), 1998, pp. 2065-2075
The absorption and subsequent desorption behaviors of amorphous polyme
r films of PEEK poly(ether ether ketone), PEEKK poly(ether ether keton
e ketone), and PEKK poly(ether ketone ketone) in solvent of 1,2-dichlo
roethane (C2H4Cl2) are investigated and compared. The equilibrium abso
rption weight (M-infinity) of these polymers is related to their molec
ular ketone content or molecular chain rigidity and also to the experi
mental conditions. Especially, at a certain temperature, the molecular
chains in the solvent can be polarized, which leads to producing grea
ter M-infinity for polymer films; for example, at 60 degrees C, M-infi
nity = 46% for PEEK and M-infinity = 65% for PEKK. The pseudodiffusion
coefficients for PEEK, PEEKK, and PEKK all surpass the 6.0 x 10(-12)
m(2) s(-1). The polymer's molecular polarization has been proved in co
ncentrated sulfur acid. Results also show that amorphous resin's films
become white and creeped in dichloroethane, which is more serious whe
n metaphenyl links are introduced into PEEKK or PEKK molecular main ch
ains. The residual solvent of 1% or so often exists in the films, even
though a long desorption time (over 100 h) has been proceeded. Absorp
tion has induced crystallization of amorphous polymer films, but this
crystallization process is slightly different from that of the films c
rystallized from both the glassy state and the melting state in the so
lvent, which makes the amorphous interlayers grow progressively and mo
re condensely; thus, the crystallized films will have higher T-g's tha
n these crystallized under annealing condition. The morphology results
have shown that the solvent-crystallized films are less toughened tha
n the amorphous ones because of the intermediate layer between the ind
uced crystallized area and the amorphous area in the core. (C) 1998 Jo
hn Wiley & Sons, Inc.