Effect of Transreactions and Additional Condensation on Structure Formation and Properties of Condensation Polymers

Calleja, F. J. Baltá; Fakirov, S.; Zachmann, H. G.

doi:10.1002/9783527613847.ch11

Cited by 5 publications

(2 citation statements)

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“…[ 26 , 27 , 28 ]. This chemical reaction can affect the miscibility of the sample by increasing the degree of miscibility through the formation of copolymers [ 26 , 29 , 30 , 31 ]. In this study, the melt blending was performed near and above the melting temperature of PET, therefore, the presence of miscibility and partial miscibility may be related to the transesterification reaction as reflected by the presence of single T g and shifting of T g towards the intermediate value between those of two polymers [ 27 , 32 ].…”

Section: Resultsmentioning

confidence: 99%

PET/Bio-Based Terpolyester Blends with High Dimensional Thermal Stability

et al. 2021

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To improve the dimensional thermal stability of polyethylene terephthalate (PET), a poly(ethylene glycol 1,4-cyclohexane dimethylene (CHDM) isosorbide (ISB) terephthalate) (PEICT) known as ECOZEN®T110 (EZT) was introduced into PET using a melt blending technique. The miscibility, morphology, and thermal properties of the PET/EZT samples were investigated. The introduction of amorphous EZT into semi-crystalline PET increased the glass transition temperature (Tg) but decreased the crystallinity, which could be related to the transesterification reaction. By adding EZT contents up to 20%, the PET/EZT samples showed a single Tg, which indicated the miscibility between PET and EZT. However, two Tg values were observed in the PET/EZT samples with higher EZT contents (30–70%), indicating partial miscibility. This may have been due to the slightly different rheological and thermodynamic parameters that were affected by a higher ratio of bulky (rigid ISB and ductile CHDM) groups in EZT. However, the heat distortion temperature of the PET/EZT samples remarkably increased, which indicated that the dimensional stability was truly enhanced. Although the crystallinity of the PET/EZT samples decreased with increasing EZT content, the tensile strength and Young’s modulus decreased slightly. Based on these results, the as-prepared PET/EZT samples with high dimensional stability can be used as a high-temperature polymeric material in various applications.

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Section: Resultsmentioning

confidence: 99%

PET/Bio-Based Terpolyester Blends with High Dimensional Thermal Stability

et al. 2021

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“…At glass fiber contents of 30 vol % or more, the viscosity of pure PA6TI was too high for the extruder to accelerate directly from 25 to 100 rpm, so the screw speed was increased in steps of 25 rpm every 15 s, and the materials were mixed for a total of 2.5 min to compensate for the initial reduction in speed. Finally, in the case of glass fiber-reinforced PA6, the neat PA6 was first compounded for 20 min at 285 °C to allow for the standard build-up of molecular weight by melt polycondensation, 61 granulated, and stored at room temperature in vacuum. It was then loaded with the required glass fiber content into the micro-extruder and compounded for 2 min at 285 °C, before injection molding.…”

Section: ■ Experimental Sectionmentioning

confidence: 99%

Thermoplastic Toughening of a Semiaromatic Polyamide with an Amino-telechelic Polyethylene

Giffin

Plummer

Frauenrath

2023

ACS Appl. Mater. Interfaces

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Semiaromatic polyamides are used for metal replacement in advanced engineering applications to reduce weight and improve efficiency, but their range of application is limited by their inherent lack of ductility and toughness. Here, we combined semiaromatic polyamide poly(hexamethylene terephthalamide-co-isophthalamide) (PA6TI) with up to 30 wt % amine-terminated polyethylene (PE(NH 2 ) 2 ) by high-temperature melt compounding, which was suggested to lead to the formation of PA-PE block copolymers at the interface between the PE(NH 2 ) 2 and the PA6TI. This resulted in PA6TI/ PE(NH 2 ) 2 blends with smaller, more uniform particle sizes than in PA6TI blended with nonfunctional PE or the commercial impact modifier, maleic anhydride-functionalized styrene−ethylene−butylene−styrene (SEBS) under the same conditions. The PA6TI/PE(NH 2 ) 2 blends and the corresponding glass fiberreinforced composites consequently showed significantly greater increases in room-temperature tensile ductility and fracture energy with respect to unmodified PA6TI, as well as maintained mechanical stability at high temperatures, and only modest decreases in stiffness and strength, even at high PE(NH 2 ) 2 contents. These improvements were attributed to the crystallinity of the PE(NH 2 ) 2 particles and to improved morphological stabilization and matrix−particle adhesion, consistent with the presence of PA-PE block copolymer at the matrix−particle interfaces.

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