Phase behavior and structure development in extruded poly(ethylene terephthalate)/poly(ethylene-2,6-naphthalate) blend

Abstract

Liquid–liquid phase separation and subsequent homogenization during annealing in an extruded poly(ethylene terephthalate) (PET)/poly(ethylene‐2,6‐naphthalate) (PEN) blend were investigated with time‐resolved light scattering and optical microscopy. In the initial stage, the domain structure was developed by demixing via spinodal decomposition. In the later stage, the blend was homogenized by transesterification between the two polyesters. The crystallization rate depended on the sequence distribution of polymer chains, which was determined by the level of transesterification rather than the composition change of separated phases. When the crystallization of PEN preceded that of PET, PEN showed a higher melting point. However, when the crystallization rate of PEN was slower than that of PET, the previously formed PET crystals suppressed the crystallization of PEN, causing the coarse crystalline structure of PEN to have a lower melting point. © 2000 John Wiley & Sons, Inc. J Polym Sci B: Polym Phys 38: 2625–2633, 2000

Correlation of Sequence Block Lengths and Degree of Randomness with Melt Rheological Properties in PET/PEN Blends

“…This mainly happens in blends prepared by an extrusion process. A liquid‐liquid phase separation and subsequent homogenization during annealing in an extruded PET/PEN blend were also reported by Bang et al22 The residence time for the melt mixing was reported to be less than 1 min. After annealing these samples at 280 °C for about 15 min the homogenization occurred.…”

Correlation of Sequence Block Lengths and Degree of Randomness with Melt Rheological Properties in PET/PEN Blends

“…This mainly happens in blends prepared by an extrusion process. A liquid‐liquid phase separation and subsequent homogenization during annealing in an extruded PET/PEN blend were also reported by Bang et al22 The residence time for the melt mixing was reported to be less than 1 min. After annealing these samples at 280 °C for about 15 min the homogenization occurred.…”

Tailoring block‐copolyesters by reactive blending of polyethylene terephthalate and polyethylene naphthalate using statistical design of experiments

“…Although the trans‐esterification of PET and PEN has been extensively studied by numerous research groups, detailed information on the influence of additional chemicals or catalysts on the rate and degree of trans‐esterification is only scarcely available from the scientific literature …”

Lamellar‐level morphology induced by combined crystallization and liquid–liquid demixing in a poly(ethylene terephthalate)/poly(ethylene‐2,6‐naphthalate) blend

“… Optical micrographs of the PET/PEN blend during annealing at 280 °C for (a) t s = 1 min, (b) t s = 3 min, (c) t s = 10 min, and (d) t s = 15 min 13…”

“…It is, therefore, interesting to investigate morphology changes at a specific crystallization‐temperature regime. We confine discussion to three representative temperatures: the first is 120 °C, at which only PET crystallizes and PEN remain amorphous; the second is 200 °C, at which PET and PEN crystallize together with some differences in the crystallization rate; and the third is 230 °C, at which the crystallization of PEN proceeds much faster than that of PET 13…”

“…The effects of the isothermal crystallization temperatures on the cold crystallization and melting behavior in the PET/PEN blend are discussed in detail in ref. 13.…”

Correlation of Sequence Block Lengths and Degree of Randomness with Melt Rheological Properties in PET/PEN Blends

“…This mainly happens in blends prepared by an extrusion process. A liquid‐liquid phase separation and subsequent homogenization during annealing in an extruded PET/PEN blend were also reported by Bang et al22 The residence time for the melt mixing was reported to be less than 1 min. After annealing these samples at 280 °C for about 15 min the homogenization occurred.…”

Tailoring block‐copolyesters by reactive blending of polyethylene terephthalate and polyethylene naphthalate using statistical design of experiments

“…Although the trans‐esterification of PET and PEN has been extensively studied by numerous research groups, detailed information on the influence of additional chemicals or catalysts on the rate and degree of trans‐esterification is only scarcely available from the scientific literature …”

Lamellar‐level morphology induced by combined crystallization and liquid–liquid demixing in a poly(ethylene terephthalate)/poly(ethylene‐2,6‐naphthalate) blend

“… Optical micrographs of the PET/PEN blend during annealing at 280 °C for (a) t s = 1 min, (b) t s = 3 min, (c) t s = 10 min, and (d) t s = 15 min 13…”

“…It is, therefore, interesting to investigate morphology changes at a specific crystallization‐temperature regime. We confine discussion to three representative temperatures: the first is 120 °C, at which only PET crystallizes and PEN remain amorphous; the second is 200 °C, at which PET and PEN crystallize together with some differences in the crystallization rate; and the third is 230 °C, at which the crystallization of PEN proceeds much faster than that of PET 13…”

“…The effects of the isothermal crystallization temperatures on the cold crystallization and melting behavior in the PET/PEN blend are discussed in detail in ref. 13.…”

Correlation of Sequence Block Lengths and Degree of Randomness with Melt Rheological Properties in PET/PEN Blends

“…This mainly happens in blends prepared by an extrusion process. A liquid‐liquid phase separation and subsequent homogenization during annealing in an extruded PET/PEN blend were also reported by Bang et al22 The residence time for the melt mixing was reported to be less than 1 min. After annealing these samples at 280 °C for about 15 min the homogenization occurred.…”

Tailoring block‐copolyesters by reactive blending of polyethylene terephthalate and polyethylene naphthalate using statistical design of experiments

“…Although the trans‐esterification of PET and PEN has been extensively studied by numerous research groups, detailed information on the influence of additional chemicals or catalysts on the rate and degree of trans‐esterification is only scarcely available from the scientific literature …”

Lamellar‐level morphology induced by combined crystallization and liquid–liquid demixing in a poly(ethylene terephthalate)/poly(ethylene‐2,6‐naphthalate) blend

“… Optical micrographs of the PET/PEN blend during annealing at 280 °C for (a) t s = 1 min, (b) t s = 3 min, (c) t s = 10 min, and (d) t s = 15 min 13…”

“…It is, therefore, interesting to investigate morphology changes at a specific crystallization‐temperature regime. We confine discussion to three representative temperatures: the first is 120 °C, at which only PET crystallizes and PEN remain amorphous; the second is 200 °C, at which PET and PEN crystallize together with some differences in the crystallization rate; and the third is 230 °C, at which the crystallization of PEN proceeds much faster than that of PET 13…”

“…The effects of the isothermal crystallization temperatures on the cold crystallization and melting behavior in the PET/PEN blend are discussed in detail in ref. 13.…”