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Crystallization kinetics of poly(1,4‐butylene‐ co ‐ethylene terephthalate)
Author(s) -
Chou ReiMei,
Chang ChiChin,
Yu T Leon,
Tseng YuHsien,
Wu MoJyi
Publication year - 2001
Publication title -
polymer international
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.592
H-Index - 105
eISSN - 1097-0126
pISSN - 0959-8103
DOI - 10.1002/1097-0126(200102)50:2<213::aid-pi615>3.0.co;2-u
Subject(s) - crystallization , materials science , copolymer , differential scanning calorimetry , polymer chemistry , ethylene glycol , crystallinity , avrami equation , ethylene , chemical engineering , polyester , nucleation , polymer , crystallization of polymers , organic chemistry , chemistry , thermodynamics , composite material , catalysis , physics , engineering
The crystallization kinetics of poly(butylene terephthalate) (PBT), poly(ethylene terephthalate) (PET), and their copolymers poly(1,4‐butylene‐ co ‐ethylene terephthalate) (PBET) containing 70/30, 65/35 and 60/40 molar ratios of 1,4‐butanediol/ethylene glycol were investigated using differential scanning calorimetry (DSC) at crystallization temperatures ( T c ) which were 35–90 °C below equilibrium melting temperature ${\bf \it T}\, _{\rm m}^{\rm o}$ . Although these copolymers contain both monomers in high proportion, DSC data revealed for copolymer crystallization behaviour. The reason for such copolymers being able to crystallize could be due to the similar chemical structures of 1,4‐butanediol and ethylene glycol. DSC results for isothermal crystallization revealed that random copolymers had a lower degree of crystallinity and lower crystallite growth rate than those of homopolymers. DSC heating scans, after completion of isothermal crystallization, showed triple melting endotherms for all these polyesters, similar to those of other polymers as reported in the literature. The crystallization isotherms followed the Avrami equation with an exponent n of 2–2.5 for PET and 2.5–3.0 for PBT and PBETs. Analyses of the Lauritzen–Hoffman equation for DSC isothermal crystallization data revealed that PBT and PET had higher growth rate constant G o , and nucleation constant K g than those of PBET copolymers. © 2001 Society of Chemical Industry