Jr. Isasi et al., POLY(4-VINYLPYRIDINE) POLY(VINYL ACETATE-CO-VINYL ALCOHOL) BLENDS - EFFECT OF SEQUENCE DISTRIBUTION ON MISCIBILITY, Polymer, 36(6), 1995, pp. 1235-1241
The miscibility of blends of poly(4-vinylpyridine) (P4VP) with blocky
copolymers of vinyl alcohol/vinyl acetate (ACA) of different compositi
ons has been investigated and compared to that of the blends with rand
om ACA copolymers. The miscibility window found in both cases is narro
wer for the blocky ACA blends, indicating the influence of the comonom
er sequence distribution. Fourier transform infra-red spectroscopy sho
ws a lower level of pyridine-hydroxy hydrogen-bonding interactions in
the case of blends with blocky ACA copolymers. Cloud point curves have
been obtained from optical microscopy measurements for several P4VP/A
CA blends. Finally, the binary interaction model including the influen
ce of the copolymer sequence distribution has been applied using Balaz
s and Cantow-Schulz approximations.