Miscibility in blends of semi-aromatic polyamides and random aliphatic
co-polyesteramides, derived from epsilon-caprolactam, epsilon-caprola
ctone and laurolactam has been investigated by calorimetric methods. D
ilution of epsilon-caprolactam by epsilon-caprolactone in PA-6 transfo
rms miscible blends based on PA-6I and PA-TMDT, respectively, to immis
cible mixtures at approximately 35 and 46 mol%, respectively, of epsil
on-caprolactone in the copolymer. The data have been found to conform
to an analysis provided by a binary interaction model incorporating se
gmental interaction parameters, chi(ij), derived from related blends.
Extension of the treatment to polyamide/polyester blends whose constit
uents contain aromaticity, e.g. PA-66/poly(ethylene terephthalate), PE
T and PA-6I/polyarylate, PAr, has also been explored. The results conf
irm the gross immiscibility, indicated by a large unfavourable interac
tion parameter, typically encountered in these blends. (C) 1997 Elsevi
er Science Ltd.