959-26-2Relevant articles and documents
A flame-retardant-free and thermo-cross-linkable copolyester: Flame-retardant and anti-dripping mode of action
Zhao, Hai-Bo,Liu, Bo-Wen,Wang, Xiao-Lin,Chen, Li,Wang, Xiu-Li,Wang, Yu-Zhong
, p. 2394 - 2403 (2014)
Flame-retardant-free and thermo-cross-linkable copolyesters have been synthesized, and their flame retardation and anti-dripping behavior as a consequence of cross-linking during combustion were investigated in detail. TG-DSC simultaneous thermal analysis, rheological analysis, and TGA established the extent and rate of the cross-linking reaction. The extent of cross-linking depends on the content of cross-linkable monomer, PEPE, and the higher the extent of the cross-linking, the better the flame retardance and anti-dripping performance of copolyesters. The large melt viscosity caused by cross-linked networks at high temperature played the most important role in anti-dripping of copolyesters. TG-FTIR results confirmed that the flame-retardant activity of copolyesters mainly took effect in the condensed phase, and XPS results indicated that the carbonization process was aromatization-dominant. SEM and Raman analysis suggested that the char layers were constituted mainly of polyaromatic species with small and uniform microstructures at the surface. Consequently, both the large melt viscosity and the formation of an especially compact char with fine microstructure resulting from cross-linking were considered as the key to the flame retardance and anti-dripping performance of the polymer when subjected to the flame.
Fe-containing magnetic ionic liquid as an effective catalyst for the glycolysis of poly(ethylene terephthalate)
Wang, Hui,Yan, Ruiyi,Li, Zengxi,Zhang, Xiangping,Zhang, Suojiang
, p. 763 - 767 (2010)
The depolymerization of poly(ethylene terephthalate) (PET) in ethylene glycol could be catalyzed by imidazolium-based Fe-containing ionic liquid, 1-butyl-3-methylimidazolium tetrachloroferrate ([bmim]FeCl4). This magnetic ionic liquid exhibits
Superparamagnetic γ-Fe2O3 nanoparticles as an easily recoverable catalyst for the chemical recycling of PET
Bartolome, Leian,Imran, Muhammad,Lee, Kyoung G.,Sangalang, Arvin,Ahn, Jeong Keun,Kim, Do Hyun
, p. 279 - 286 (2014)
There have been numerous studies to develop catalysts for the chemical recycling of poly(ethylene terephthalate) (PET) via glycolysis. However, in the field of PET glycolysis, only a few have attempted to recover and reuse the catalysts. This research utilized easily recoverable superparamagnetic γ-Fe2O3 nanoparticles as a reusable catalyst for PET glycolysis. γ-Fe2O3 nanoparticles were produced by calcining Fe3O4 nanoparticles prepared by the co-precipitation method. The produced γ-Fe2O3 nanoparticles had an average size of 10.5 ± 1.4 nm, and a very high surface area reaching 147 m2 g-1. Its superparamagnetic property was also confirmed. Glycolysis reactions were carried out, and the γ-Fe2O3 catalysts were recovered after the reactions by simple magnetic decantation. The use of magnetic iron oxide allowed the easy recovery of the catalyst from the glycolysis products. At 300 °C and a 0.05 catalyst/PET weight ratio, the maximum bis(2-hydroxyethlyl) terephthalate (BHET) monomer yield reached more than 90% in 60 min. At 255 °C and a 0.10 catalyst/PET weight ratio, the BHET yield reached more than 80% in 80 min. The catalyst was reused 10 times, giving almost the same BHET yield each time.
(Mg-Zn)-Al layered double hydroxide as a regenerable catalyst for the catalytic glycolysis of polyethylene terephthalate
Eshaq, Gh.,Elmetwally
, p. 1 - 6 (2016)
(Mg-Zn)-Al layered double hydroxide (LDH) was prepared by the coprecipitation method at low super saturation conditions. The prepared (Mg-Zn)-Al LDH was analyzed using XRD, FTIR, N2 adsorption-desorption, TGA and DSC, confirming the formation of pure LDH phase. The extent of polyethylene terephthalate (PET) degradation by the glycolysis process was studied using the prepared (Mg-Zn)-Al LDH. The glycolysis process was optimized in terms of catalyst concentration, temperature, time, ethylene glycol dosage. Under the optimal conditions of 1.0 wt.% of catalyst with 20 g of ethylene glycol (EG) in the presence of 2.0 g of PET at 196 °C after 3 h of glycolysis, complete PET conversion was achieved and the yield of bis (2-hydroxyethyl) terephthalate (BHET) reached 75%.
Dielectric relaxation in amorphous poly(ethylene terephthalate) and poly(ethylene 2,6-naphthalene dicarboxylate) and their copolymers
Bravard, Shelly P.,Boyd, Richard H.
, p. 741 - 748 (2003)
The dielectric loss spectra of poly(ethylene 2,6-naphthylene dicarboxylate) (PEN) and several copolymers of 2,6-naphthylene dicarboxylic acid and terephthalic acid with ethylene glycol have been studied over a wide range of frequency and temperature. Previously, Ezquerra, Balta-Calleja, and Zachmann have reported the presence, in isochronal temperature scans of dielectric loss, of a subglass process (β*) in PEN homopolymer in addition to the subglass process (β) similar to that in poly(ethylene terephthalate) (PET). In the present work both the β and β* processes in PEN and PET/PEN copolymers are resolved and characterized in isothermal frequency scans. It was found that the lower temperature β loss peak in PEN and the copolymers has a complex or composite frequency domain structure requiring two Cole-Cole processes in its representation. The β* process in the copolymers is found to shift to higher frequency isothermally (or lower temperature isochronally) with increasing terephthalic acid content. Analysis of previous dielectric data for PET shows that its β subglass process is also complex in the log frequency axis but must be represented by three Cole-Cole processes. The two higher frequency components are essentially identical to the two Cole-Cole processes making up the β process in PEN. The third and lowest frequency component is interpreted as of the same origin as the β* process in PEN and the copolymers but shifted to higher frequency isothermally (or lower temperature isochronally) to where it overlaps with the β process.
Effective catalysts derived from waste ostrich eggshells for glycolysis of post-consumer PET bottles
Yunita, Isti,Putisompon, Siraphat,Chumkaeo, Peerapong,Poonsawat, Thinnaphat,Somsook, Ekasith
, p. 1547 - 1560 (2019)
Herein, we report an effective chemical recycling of poly(ethylene terephthalate) (PET) using sustainable sources of catalysts, calcium oxide (CaO) derived from ostrich eggshells. The active catalysts were demonstrated in the chemical depolymerization of post-consumer PET bottles. Beverage bottles were proceeded with 1 wt% catalyst derived from ostrich eggshells in the presence of ethylene glycol at 192?°C under atmospheric pressure to give the major product as bis(2-hydroxyethyl terephthalate) (BHET) which was confirmed by melting point, IR spectroscopy, 1H-, 13C-NMR spectroscopy and mass spectrum. The catalyst could fully depolymerize PET within 2?h, producing a good yield of highly pure BHET monomer. The catalysts were successfully characterized by X-ray powder diffraction (XRD), X-ray photoelectron spectroscopy (XPS), field-emission scanning electron microscopy with energy dispersive X-ray spectroscopy analysis (FE-SEM), and thermo-gravimetric analysis (TGA). Furthermore, catalysts derived from chicken eggshells, geloina, mussel, and oyster shells were run to compare the catalytic activities. For better understanding of catalytic parameters, effects of calcination temperatures of catalyst, weight ratio of catalyst, ratio of weight of solvent, and time of depolymerization for the ostrich eggshells catalyst were also investigated.
Organocatalysed depolymerisation of PET in a fully sustainable cycle using thermally stable protic ionic salt
Jehanno, Coralie,Flores, Irma,Dove, Andrew P.,Müller, Alejandro J.,Ruipérez, Fernando,Sardon, Haritz
, p. 1205 - 1212 (2018)
The world's plastic production is continuously and exponentially increasing, creating millions of tons of short-lived items that end as waste and accumulate in the environment. Poly(ethylene terephthalate) (PET) provides one of the best examples as it is a non-biodegradable polymer that is mainly used as raw material for a wide range of packaging applications, making degradation of PET a subject of great interest for researchers. Herein we report a sustainable process for the chemical recycling of PET from waste to a new polymer using an innovative protic ionic salt. Using a simple solvent-free process, post-consumer PET bottles are degraded into bis(2-hydroxyethyl) terephthalate (BHET) monomer. The catalyst, formed by an equimolar quantity of triazabicyclodecene (TBD) and methanesulfonic acid (MSA), completely depolymerises PET in less than 2 h, producing 91% of highly pure BHET. Due to the unusual thermal stability of the TBD:MSA salt, the catalyst can be recycled at least 5 times to depolymerise more PET waste. In addition, we demonstrate that the monomer obtained from the degradation reaction can be used to synthesise new PET with similar thermal properties to that produced using a conventional polycondensation method. The protic ionic salt catalyst combines the excellent catalytic ability of organocatalysts with the thermal stability of metal catalysts, resisting degradation up to >400 °C, thus for the first time presenting an industrially-relevant organocatalyst for high-temperature polymer degradation and recycling.
Mechanically linked poly(ethylene terephthalate)
Fustin,Clarkson,Leigh,Van Hoof,Jonas,Bailly
, p. 7884 - 7892 (2004)
The synthesis, by solid-state copolymerization, and properties of poly(ethylene terephthalate) (PET) copolymers containing various amounts of [2]catenane mechanical linkages are described. Polymers end-capped by the corresponding noninterlocked macrocycle as well as a copolymer with a rigid fluorene monomer unit were also prepared as reference systems. Size exclusion chromatography and 1H NMR indicate that the catenane is quantitatively incorporated during synthesis but that a small fraction ring-opens to form noninterlocked macrocycles, incorporated as either chain ends or branching points. Catenanes induce a smaller increase in the glass transition temperature than the macrocycle at the same weight content. This is probably due to the suppression of interchain hydrogen bonds upon interlocking and points to a specific effect of the mechanical linkage on properties. The crystallization and melting temperatures of catenane copolymers are only slightly depressed compared to those of PET homopolymer, further demonstrating significant flexibility of the catenane rings. SAXS results show that the amorphous interlayer between lamellae increases with increasing catenane content at constant lamellar thickness, confirming that the uncrystallizable catenane units concentrate in the amorphous phase during solid-state polymerization.
DISPERSION AND METHOD AND COMPOSITION FOR PREPARING THE SAME
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Paragraph 0036, (2021/12/03)
A dispersion includes a zinc oxide component, and an aromatic polyol which is represented by Formula (I) and which has terminal hydroxyl groups that form chelating bonds with zinc atoms of the zinc oxide component, wherein p and q are independently integers ranging from 1 to 40. A method for preparing the dispersion includes heating a composition including the aromatic polyol and a zinc-containing salt, so that the zinc-containing salt undergoes nucleophilic reaction and condensation reaction to form the zinc oxide component. A composition for preparing the dispersion is also disclosed.
Preparation method of bis (2-hydroxyethyl) terephthalate
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Paragraph 0026; 0030-0032; 0036-0038; 0042-0044; 0047-0050, (2020/04/22)
The invention relates to a preparation method of bis (2-hydroxyethyl) terephthalate. Terephthalic acid and ethylene oxide are used as raw materials to prepare bis (2-hydroxyethyl) terephthalate; a Lewis acid ionic liquid is selected as a solvent and a catalyst; the invention provides the preparation method of bis (2-hydroxyethyl) terephthalate which suitable for industrial production, the conversion rate of terephthalic acid in the preparation method is 90% or above, the selectivity on bis (2-hydroxyethyl) terephthalate is up to 95% or above, and the preparation method is simple in process andsuitable for requirements of industrial production.
