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Miscibility and Crystallization Behavior of Poly(ethylene terephthalate)/Poly(vinylidene fluoride) Blends
Author(s) -
Rahman M. Habibur,
Nandi Arun K.
Publication year - 2002
Publication title -
macromolecular chemistry and physics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.57
H-Index - 112
eISSN - 1521-3935
pISSN - 1022-1352
DOI - 10.1002/1521-3935(20020301)203:4<653::aid-macp653>3.0.co;2-#
Subject(s) - miscibility , poly ethylene , polymer chemistry , fluoride , crystallization , materials science , ethylene , polymer blend , polymer science , chemical engineering , copolymer , chemistry , organic chemistry , polymer , composite material , catalysis , inorganic chemistry , engineering
Poly(ethylene terephthalate) (PET) and poly(vinylidene fluoride) (PVF 2 ) are miscible in the melt‐state for the whole composition range. The glass transition temperature ( T g ) of the solvent cast film decreases with the decrease in W PET (weight fraction of PET) in the blend, however, the T g for the repeated melt quenched blends remains invariant with W PET . The melting point ( T m ) and crystallization temperature ( T c ) of PET decrease significantly with decrease in W PET in the blend, but the T m and T c of PVF 2 decrease slightly with increase in W PET . The crystallinity of both PET and PVF 2 decreases with increasing concentration of the other component in the blend, however, the decrease is larger for the former. The equilibrium melting points ( T m 0 's) of PET in the blends are determined by the extrapolation procedures using (i) T m – T c method for 5% crystallinity and (ii) T m – T a method, where T m , T c and T a are melting, crystallization and annealing temperatures, respectively. The data of both the methods indicate a large depression of T m 0 of PET with increase in PVF 2 concentration. The χ 12 values determined from both the data are essentially the same, –0.14. This negative value of χ 12 indicates that the two polymers are miscible in the melt‐state, however, they are not miscible in the crystalline state. The onset of degradation of PET increases with increase in PVF 2 concentration in the blend.