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Crystallization of poly(ethylene terephthalate) and poly (butylene terephthalate) modified by diamides
Author(s) -
Bouma Krista,
Gaymans Reinoud J.
Publication year - 2001
Publication title -
polymer engineering and science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.503
H-Index - 111
eISSN - 1548-2634
pISSN - 0032-3888
DOI - 10.1002/pen.10743
Subject(s) - materials science , crystallization , dimethyl terephthalate , extrusion , ethylene , differential scanning calorimetry , chemical engineering , copolymer , polymer chemistry , composite material , molding (decorative) , talc , polymer , organic chemistry , catalysis , polyester , chemistry , physics , engineering , thermodynamics
Poly(ethylene terephthalate) (PET) and poly (butylene terephthalate) have been modified by diamide units (0.1–1 mol%) in an extrusion process and the crystallization behavior studied. The diamides used were: for PET, T2T‐dimethyl (N, N′‐bis( p ‐carbomethoxybenzoyl)ethanediamine) and for PBT, T4T‐dimethyl (N, N′‐bis( p ‐carbomethoxybenzoyl)butanediamine). The above materials were compared to talc (0.5 wt%), this being a standard heterogeneous nucleator, and to diamide modified copolymers obtained by a reactor process. Two PET materials were used: a slowly crystallizing recycled grade obtained from soft drink bottles and a rapidly crystallizing injection molding grade. The crystallization was studied by differential scanning calometry (DSC) and under injection molding conditions using wedge shaped specimens; the thermal properties were studied by dynamic mechanical analysis. T2T‐dimethyl is effective in increasing the crystallization of PET in both of the extrusion compounds as well as in the reactor materials. It was also found that the crystallization temperature of poly(butylene terephthalate) could be slightly increased by the addition of nucleators.