Ta. Ezquerra et al., Relaxation behavior in model compounds of poly(aryl-ether-ketone-ketone) as revealed by dielectric spectroscopy, J CHEM PHYS, 110(20), 1999, pp. 10134-10140
The relaxation behavior of a series of ether-ketone oligomers, considered a
s model compounds of poly(ether-ketone-ketone), was studied by means of die
lectric spectroscopy. The dynamics of the a relaxation of ether-ketone mode
l compounds as compared with that of poly(aryl-ether-ketone-ketone) (PEKK)
(50/50), shows up differences which can be attributed to the variation of i
nter- and intramolecular correlations with the chain length. Model compound
s exhibit a nearly similar degree of cooperativity regardless the differenc
es in T-g values. The PEKK (50/50) polymer exhibits stronger cooperativity
than the oligomers suggesting that in poly(ether-ketone-ketone)s molecular
motions above T-g extend to more than one monomeric unit. (C) 1999 American
Institute of Physics. [S0021-9606(99)50620-8].