scholarly journals New Aspects Concerning the Structure and Degree of Crystallinity in High-Pressure-Crystallized Poly(ethylene terephthalate)

1996 ◽  
Vol 29 (18) ◽  
pp. 6019-6022 ◽  
Author(s):  
U. Köncke ◽  
H. G. Zachmann ◽  
F. J. Baltá-Calleja
Keyword(s):  
High Pressure ◽  
Ethylene Terephthalate ◽  
Degree Of Crystallinity ◽  
Poly Ethylene Terephthalate ◽  
Poly Ethylene

Fracture and Deformation of Extended-Chain Crystals in Poly(ethylene Terephthalate)/Bisphenol-A Polycarbonate Blends Crystallized at High Pressure

2011 ◽  
Vol 214 ◽  
pp. 301-305
Author(s):  
Jun Lu ◽  
Jiao Jiao Tian ◽  
Dao Peng Zhang ◽  
Rui Huang
Keyword(s):  
High Pressure ◽  
Bisphenol A ◽  
Single Crystals ◽  
Ethylene Terephthalate ◽  
Morphological Observation ◽  
Bisphenol A Polycarbonate ◽  
Extended Chain ◽  
Poly Ethylene Terephthalate ◽  
Poly Ethylene ◽  
Functional Components

With a combination of three-dimensional crystal ordering and long-chain molecular orientational ordering, the extended-chain crystals of polymers are ideal system for the studies on low-dimensional physics, and have potential applications as functional components. In this study, poly (ethylene terephthalate) / bisphenol-A polycarbonate (PET/BAPC) blend samples were prepared with solid phase forming technique under high pressure, and extended-chain single crystals with large c-axis thickness were formed within a relative short time. The fracture and deformation behaviors of the grownup crystals were investigated using scanning electron microscopy (SEM) and atomic force microscopy (AFM). Morphological observation showed that most of the extended-chain crystals were endowed with perfect appearance after the sample fracture. However, there were still a few crystals fractured apart, along or perpendicularly to their c-axis direction, or with cohesive fracture surfaces. Fractured spherulites with extended-chain lamellae as substructures were also disclosed in extended-chain crystals with AFM. Furthermore, the parallel lamellae deformed and changed their striation direction during the crystal growth, as was observed on a kind of extended-chain crystals grown in a PET oligomer and BAPC blend (PETO/BAPC). This study may be instructive to the improvement of the separation technique of such single crystals, so as to hasten their real applications.

Improving the properties of recycled PET/PEN blends by using different chain extenders

2016 ◽  
Vol 36 (6) ◽  
pp. 615-624 ◽  
Author(s):  
Simge Can ◽  
N. Gamze Karsli ◽  
Sertan Yesil ◽  
Ayse Aytac
Keyword(s):  
Ethylene Terephthalate ◽  
Chain Extender ◽  
Degree Of Crystallinity ◽  
Recycled Pet ◽  
H Nmr ◽  
Loading Level ◽  
Poly Ethylene Terephthalate ◽  
Chain Extenders ◽  
Izod Impact ◽  
Poly Ethylene

Abstract The main aim of this study was to improve the mechanical properties of the recycled poly(ethylene terephthalate)/poly(ethylene 2,6-naphthalate) (r-PET/PEN) blends by enhancing the miscibility between PET and PEN with the usage of chain extenders. This idea was novel for the recycled PET-based r-PET/PEN blends, as investigation of the effects of the chain extender usage on the properties of r-PET/PEN blends has not been studied in the literature, according to our knowledge. 1,4-Phenylene-bis-oxazoline (PBO), 1,4-phenylene-di-isocyanate (PDI), and triphenyl phosphite (TPP) were selected as chain extenders. The maximum tensile strength value was observed for the 1.0PDI sample. Moreover, PDI-based blends exhibited better Izod impact strength when compared with all other samples. The miscibility and degree of crystallinity values of all blends were discussed by means of thermal analysis. 1H-nuclear magnetic resonance (1H-NMR) analysis was carried out to determine transesterification reaction levels. According to 1H-NMR results, the increase in the level of transesterification was around 40% with the usage of PDI. The optimum loading level for selected chain extenders was determined as 1 wt.%, and PDI-based blends exhibited better properties when compared with those of the blends based on PBO and TPP at this loading level.

scholarly journals Microhardness and structure of high pressure crystallized poly(ethylene terephthalate)

Polymer ◽  
1994 ◽  
Vol 35 (22) ◽  
pp. 4775-4779 ◽  
Author(s):  
F.J. Baltá^Calleja ◽  
O. Öhm ◽  
R.K. Bayer
Keyword(s):  
High Pressure ◽  
Ethylene Terephthalate ◽  
Poly Ethylene Terephthalate ◽  
Poly Ethylene

Crystallization Processes In Poly (Ethylene Terephthalate) / Polycarbonate Blends

1993 ◽  
Vol 321 ◽  
Author(s):  
Veronika E. Reinsch ◽  
Ludwig Rebenfeld
Keyword(s):  
Ethylene Terephthalate ◽  
Crystallization Rate ◽  
Melt Processing ◽  
Degree Of Crystallinity ◽  
Processing Temperature ◽  
Scanning Calorimetry ◽  
Processing Times ◽  
Poly Ethylene Terephthalate ◽  
Poly Ethylene ◽  
Crystallization From The Melt

ABSTRACTBlends of poly (ethylene terephthalate), or PET, and polycarbonate (PC) over a range of compositions were studied in isothermal crystallizations from the melt using differential scanning calorimetry (DSC). Both crystallization rate and degree of crystallinity of PET depend on blend composition. The glass transition temperature, Tg, of PET and PC in blends and pure polymer were also measured by DSC. Elevation of the Tg of PET and depression of the Tg of PC are observed upon blending. In cooling scans, dynamic crystallization from the melt was observed. In PET/PC blends with high PC content, a novel dual-peak crystallization of PET was observed. The effects of thermal history on crystallization kinetics and degree of crystallinity were also determined in isothermal crystallization studies. For Melt processing times between 1 and 30 Min and for processing temperatures between 280 and 300 °C, Melt processing temperature was seen to have a stronger effect than processing time.

scholarly journals Electrical, Thermal, and Morphological Properties of Poly(ethylene terephthalate)-Graphite Nanoplatelets Nanocomposites

2017 ◽  
Vol 2017 ◽  
pp. 1-9 ◽  
Author(s):  
Basheer A. Alshammari ◽  
Arthur N. Wilkinson ◽  
Ghzzai Almutairi
Keyword(s):  
Electrical Conductivity ◽  
Percolation Threshold ◽  
Ethylene Terephthalate ◽  
Threshold Value ◽  
Morphological Properties ◽  
Degree Of Crystallinity ◽  
Graphite Nanoplatelets ◽  
Melt Compounding ◽  
Poly Ethylene Terephthalate ◽  
Poly Ethylene

Graphite nanoplatelets (GNP) were incorporated with poly(ethylene terephthalate) (PET) matrix by melt-compounding technique using minilab compounder to produce PET-GNP nanocomposites, and then the extruded nanocomposites were compressed using compression molding to obtain films of 1 mm thickness. Percolation threshold value was determined using percolation theory. The electrical conductivity, morphology, and thermal behaviors of these nanocomposites were investigated at different contents of GNP, that is, below, around, and above its percolation threshold value. The results demonstrated that the addition of GNP at loading >5 wt.% made electrically conductive nanocomposites. An excellent electrical conductivity of ~1 S/m was obtained at 15 wt.% of GNP loading. The nanocomposites showed a typical insulator-conductor transition with a percolation threshold value of 5.7 wt.% of GNP. In addition, increasing screw speed enhanced the conductivity of the nanocomposites above its threshold value by ~2.5 orders of magnitude; this behavior is attributed to improved dispersion of these nanoparticles into the PET matrix. Microscopies results exhibited no indication of aggregations at 2 wt.% of GNP; however, some rolling up at 6 wt.% of GNP contents was observed, indicating that a conductive network has been formed, whereas more agglomeration and rolling up could be seen as the GNP content is increased in the PET matrix. These agglomerations reduced their aspect ratio and then reduced their reinforcement efficiency. NP loading (>2 wt.%) increased degree of crystallinity and improved thermal stability of matrix slightly, suggesting that 2 wt.% of GNP is more than enough to nucleate the matrix.

Stereo-open spherulites in high-pressure crystallized poly (ethylene terephthalate)

2000 ◽  
Vol 216 (1-4) ◽  
pp. 538-541 ◽  
Author(s):  
Liangbin Li ◽  
Huang Rui ◽  
Ai Lu ◽  
Wuyi Fan ◽  
Shiming Hong ◽  
...  
Keyword(s):  
High Pressure ◽  
Ethylene Terephthalate ◽  
Poly Ethylene Terephthalate ◽  
Poly Ethylene
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