Properties of poly(ethylene terephthalate)/poly(ethylene naphthalate) blends (original) (raw)
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Miscibility and crystallisation behaviour of poly(ethylene terephthalate)/polycarbonate blends
Polymer, 2002
Poly(ethylene terephthalate)/polycarbonate blends were produced in a twin-screw extruder with and without added transesteri®cation catalyst, lanthanum acetyl acetonate. The miscibility of the blends was studied from their crystallisation behaviour and variation in glass transition temperature with composition using differential scanning calorimetry, scanning electron microscopy and change in mechanical properties. The blends prepared without the catalyst showed completely immiscible over all compositions, while those prepared in the presence of the catalyst showed some limited miscible. The presence of PC inhibited the crystallisation of PET but this was much greater in the blends prepared in the presence of catalyst suggesting that some reaction had taken place between the two polyesters. The tensile properties showed little differences between the two types of blends. q
The European Physical Journal E, 2005
The isothermal cold crystallization of poly(ethylene terephthalate)(PET) in cryogenic mechanical alloyed blends of PET and Poly(ethylene naphthalene 2,6-dicarboxilate)(PEN) 1:1 by weight has been investigated by simultaneous small and wide angle X-ray scattering (SAXS and WAXS) and dielectric spectroscopy (DS). For transesterification levels higher than 23% the blends tend to transform into a onephase system and the crystallization of PET is strongly inhibited due to the significant reduction of the PET segment length. For lower levels of transesterification the blends are phase separated and the overall crystallization behaviour can be explained considering the confined nature of the PET domains in these blends. The formation of a rigid amorphous phase in the intra-lamellar stack amorphous regions is reduced in the blends due to a lower probability of stack formation in the confined PET-rich domains. The more effective filling of the space by the lamellar crystals in the blends provokes a stronger restriction to the amorphous phase mobility of PET in the blends than in pure PET.
Spectroscopic analysis of poly (ethylene naphthalate)poly (butylene terephthalate) blends
Journal of Applied …, 2007
The characteristics of poly(butylene terephthalate) (PBT), poly(ethylene naphthalate) (PEN), and blends with 30, 40, 50, 60, and 70 wt % PEN prepared by melt-blending were analyzed using Fourier transform infrared spectroscopy, Raman spectroscopy, X-ray diffraction, solid-state nuclear magnetic resonance (NMR), and Xray photoelectron spectroscopy. The spectroscopic analyses provide no direct evidence for the occurrence of transesterification reactions occurring during melt-processing of the blends under the conditions that were used. The improved mechanical properties of the PBT/PEN blends are attributed to physical interactions occurring over a large interfacial area. X-ray diffraction and high-resolution solid-state carbon-13 (13 C) NMR confirmed the formation of the a-PEN phase after annealing samples at 2008C for 19 h.
Engineering, Technology & Applied Science Research, 2022
In this paper, blends of recycled polyethylene terephthalate (r-PET) and high-density polyethylene (HDPE) with and without a compatibilizer were prepared using a Brabender Haake Rheocord at 270°C and 32rpm. Ethylene vinyl acetate was chosen as the compatibilizer and its proportion was set to 5, 7, and 10 wt%. The thermal properties and crystallization behavior were determined by Differential Scanning Calorimetry (DSC). Micromechanical properties were also investigated using a Vickers microindentation tester. The DSC analysis indicates that the melting temperature of r-PET and HDPE in all the blends, compatibilized and uncompatibilized, remains constant and almost the same as those of the pure component. On the other hand, it is shown that the degree of crystallinity of HDPE in the blends calculated by DSC depends on the composition of the polymeric mixture. However, the Hardness (H) decreases with increasing r-PET content until 50/50 composition of r-PET/HDPE is reached, whereas for larger r-PET content values, H increases. The same trend was obtained with the addition of the compatibilizer.
Polímeros, 2014
A systematic study of solid state polymerization (SSP), concerning the melt extruded blend of poly(ethylene terephthalate)/polycarbonate (catalyzed PET/PC, 80/20 wt %), as a function of temperature range (180-190°C) for a fixed time (6 h) is presented. The materials obtained were evaluated by differential scanning calorimetry (DSC), thermogravimetry/derivative thermogravimetry (TG/DTG), optical microscopy (OM) and intrinsic viscosity (IV) analysis. After SSP, at all reaction temperatures, PET glass transition and heating crystallization temperatures slightly decreased, melting temperature slightly increased, while degree of crystallinity was practically invariable. The DTG curves indicated that, at least, three phases remained. The OM images revealed that the morphology is constituted of a PET matrix and a PC dispersed phase. In the interfacial region we noticed the appearance of structures like bridges linking the matrix and the dispersed domains. These bridges were correlated to the PET/PC block copolymer obtained during blending in the molten state. IV increased for all polymerization temperatures, due to the occurrence of PET chain extension reactions-esterification and transesterification. The IV range for bottle grade PET was achieved.
Polymer, 2010
The structure and properties of blends of poly(ethylene terephthalate) (PET) with poly(trimethylene terephthalate) (PTT) at PTT concentration 30 wt.%, obtained with three different methods: from solution, melt extrusion, and direct spinning, are investigated. Relationships between the method of preparation and properties of blends are established. All blends show glass transition temperature at values determined by composition, and crystallization properties also dependent on the preparation method. Blends obtained from solution show separated melting of components. For blends obtained from the melt only PET crystallizes. The melting temperature decreases with the residence time of the melt at high temperatures, due to occurrence of ester exchange reactions. It is shown that reactive blending of PET/PTT mixtures occurring during preparation is a versatile route for obtainment of engineering materials with good mechanical properties, high crystallinity, glass transition temperature lower than that of PET, and melting temperature that may be controlled by the processing conditions.
Journal of Polymer Science Part B: Polymer Physics, 2004
Blends of poly(trimethylene terephthalate) (PTT) and poly(ethylene terephthalate) in the amorphous state were miscible in all of the blend compositions studied, as evidenced by a single, composition-dependent glass-transition temperature observed for each blend composition. The variation in the glass-transition temperature with the blend composition was well predicted by the Gordon-Taylor equation, with the fitting parameter being 0.91. The cold-crystallization (peak) temperature decreased with an increasing PTT content, whereas the melt-crystallization (peak) temperature decreased with an increasing amount of the minor component. The subsequent melting behavior after both cold and melt crystallizations exhibited melting point depression behavior in which the observed melting temperatures decreased with an increasing amount of the minor component of the blends. During crystallization, the pure components crystallized simultaneously just to form their own crystals. The blend having 50 wt % of PTT showed the lowest apparent degree of crystallinity and the lowest tensile-strength values. The steady shear viscosity values for the pure components and the blends decreased slightly with an increasing shear rate (within the shear rate range of 0.25-25 s Ϫ1 ); those of the blends were lower than those of the pure components. © 2004 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 42: 676 -686, 2004