scholarly journals Cu/CuO Composite Track-Etched Membranes for Catalytic Decomposition of Nitrophenols and Removal of As(III)

Nanomaterials ◽  
2020 ◽  
Vol 10 (8) ◽  
pp. 1552
Author(s):  
Anastassiya A. Mashentseva ◽  
Murat Barsbay ◽  
Maxim V. Zdorovets ◽  
Dmitriy A. Zheltov ◽  
Olgun Güven
Keyword(s):  
Catalytic Activity ◽  
Cross Flow ◽  
Catalytic Decomposition ◽  
Composite Membranes ◽  
Degree Of Crystallinity ◽  
Flow Mode ◽  
Pristine Sample ◽  
Poly Ethylene Terephthalate ◽  
Poly Ethylene ◽  
High Conversion Yield

One of the promising applications of nanomaterials is to use them as catalysts and sorbents to remove toxic pollutants such as nitroaromatic compounds and heavy metal ions for environmental protection. This work reports the synthesis of Cu/CuO-deposited composite track-etched membranes through low-temperature annealing and their application in catalysis and sorption. The synthesized Cu/CuO/poly(ethylene terephthalate) (PET) composites presented efficient catalytic activity with high conversion yield in the reduction of nitro aryl compounds to their corresponding amino derivatives. It has been found that increasing the time of annealing raises the ratio of the copper(II) oxide (CuO) tenorite phase in the structure, which leads to a significant increase in the catalytic activity of the composites. The samples presented maximum catalytic activity after 5 h of annealing, where the ratio of CuO phase and the degree of crystallinity were 64.3% and 62.7%, respectively. The catalytic activity of pristine and annealed composites was tested in the reduction of 4-nitroaniline and was shown to remain practically unchanged for five consecutive test cycles. Composites annealed at 140 °C were also tested for their capacity to absorb arsenic(III) ions in cross-flow mode. It was observed that the sorption capacity of composite membranes increased by 48.7% compared to the pristine sample and reached its maximum after 10 h of annealing, then gradually decreased by 24% with further annealing.

Mechanistic Insight toward the Roles of Anions and Cations in the Degradation of Poly (ethylene terephthalate) Catalyzed by Ionic Liquids

2021 ◽  
Author(s):  
Zhaoyang Ju ◽  
Lei Zhou ◽  
Xingmei Lu ◽  
Yao Li ◽  
Xiaoqian Yao ◽  
...  
Keyword(s):  
Catalytic Activity ◽  
Ionic Liquids ◽  
Ethylene Terephthalate ◽  
High Catalytic Activity ◽  
Mechanistic Insight ◽  
Poly Ethylene Terephthalate ◽  
Anions And Cations ◽  
Poly Ethylene

Ionic liquids (ILs) have shown high catalytic activity in the degradation of poly (ethylene terephthalate) (PET), but the effects of anions and cations as well as the mechanism remain ambiguous....

scholarly journals Biobased Engineering Thermoplastics: Poly(butylene 2,5-furandicarboxylate) Blends

Polymers ◽  
2019 ◽  
Vol 11 (6) ◽  
pp. 937 ◽  
Author(s):  
Niki Poulopoulou ◽  
George Kantoutsis ◽  
Dimitrios N. Bikiaris ◽  
Dimitris S. Achilias ◽  
Maria Kapnisti ◽  
...  
Keyword(s):  
Renewable Resources ◽  
Degree Of Crystallinity ◽  
X Ray Diffraction ◽  
Reactive Blending ◽  
Scanning Calorimetry ◽  
Melt Polycondensation ◽  
Poly Ethylene Terephthalate ◽  
Furandicarboxylic Acid ◽  
Poly Ethylene ◽  
Poly Propylene

Poly(butylene 2,5-furandicarboxylate) (PBF) constitutes a new engineering polyester produced from renewable resources, as it is synthesized from 2,5-furandicarboxylic acid (2,5-FDCA) and 1,4-butanediol (1,4-BD), both formed from sugars coming from biomass. In this research, initially high-molecular-weight PBF was synthesized by applying the melt polycondensation method and using the dimethylester of FDCA as the monomer. Furthermore, five different series of PBF blends were prepared, namely poly(l-lactic acid)–poly(butylene 2,5-furandicarboxylate) (PLA–PBF), poly(ethylene terephthalate)–poly(butylene 2,5-furandicarboxylate) (PET–PBF), poly(propylene terephthalate)–poly(butylene 2,5-furandicarboxylate) (PPT–PBF), poly(butylene 2,6-naphthalenedicarboxylate)-poly(butylene 2,5-furandicarboxylate) (PBN–PBF), and polycarbonate–poly(butylene 2,5-furandicarboxylate) (PC–PBF), by dissolving the polyesters in a trifluoroacetic acid/chloroform mixture (1/4 v/v) followed by coprecipitation as a result of adding the solutions into excess of cold methanol. The wide-angle X-ray diffraction (WAXD) patterns of the as-prepared blends showed that mixtures of crystals of the blend components were formed, except for PC which did not crystallize. In general, a lower degree of crystallinity was observed at intermediate compositions. The differential scanning calorimetry (DSC) heating scans for the melt-quenched samples proved homogeneity in the case of PET–PBF blends. In the remaining cases, the blend components showed distinct Tgs. In PPT–PBF blends, there was a shift of the Tgs to intermediate values, showing some partial miscibility. Reactive blending proved to improve compatibility of the PBN–PBF blends.

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.

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.

Microstructure of Thermally Crosslinkable Poly(Ethylene Terephthalate) (Pet-co-Xta) Benzocyclobutene Functionalized Copolymers

1996 ◽  
Vol 461 ◽  
Author(s):  
Brendan J. Foran ◽  
Elizabeth Pingel ◽  
Gary E. Spilman ◽  
Larry J. Markoski ◽  
Tao Jiang ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Degree Of Crystallinity ◽  
Limiting Oxygen Index ◽  
X Ray Scattering ◽  
Transmission Electron ◽  
Poly Ethylene Terephthalate ◽  
Stable Flame ◽  
Poly Ethylene ◽  
Crystalline Domains ◽  
The Degree Of Crystallinity

ABSTRACTThe microstructure and thermal properties of copolymers of polyethylene terephthalate (PET) containing a crosslinkable terephthalic acid, 1,2-dihydrocyc Iobutabenzene 3,6 dicarboxylic acid (XTA) are reported. Wide angle x-ray scattering (WAXS) show that the addition of XTA does not alter the PET crystal structure in copolymers at low XTA contents. However, the degree of crystallinity drops for higher XTA levels. WAXS profiles show that PET-co-XTA 50% is amorphous, and that PEXTA homopolymer has a different crystal structure. Thermal data from DSC and TGA show that crosslinking of the benzocyclobutene groups (∼350°C) occurs at temperatures between melting (∼250°C) and degradation (∼400°C), making it possible to melt process the copolymers into fibers before the onset of crosslinking. Limiting oxygen index (LOI) measurements show that increased oxygen concentrations are required to sustain a stable flame in PET-co-XTA copolymers; whereas unmodified PET had an LOI value of -18%, the copolymers had LOI values near 32%. Further, while unmodified PET melts and drips as it burns, XTA copolymers formed a stable char that inhibiting flame propagation. An increased char was observed in optical micrographs for XTA containing polymers, and crystalline domains were observed near the burn surface in transmission electron micrographs.

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.

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