Latent heat of sublimation of terephthalic acid from differential thermal analysis data

Lucchesi, Claude A.; Lewis, W. T.

doi:10.1021/je60038a026

Cited by 24 publications

(14 citation statements)

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“…The “solvent‐free” synthesis technique addresses a prominent cost and environmental concern of many MOF syntheses by forming the MOF directly in the organic acid itself, therefore eliminating the use of large quantities of solvents required for most solvothermal syntheses, which can be cost prohibitive and require additional waste disposal costs and concerns. However, certain organic ligands are difficult if not impossible to maintain in a liquid phase (e.g., terephthalic acid) . Despite the direct significance of these techniques, the applicability of any one synthesis method to all MOF structures is unlikely.…”

Section: Introductionmentioning

confidence: 99%

Kinetics study and crystallization process design for scale‐up of UiO‐66‐NH₂ synthesis

et al. 2012

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A comprehensive scale-up procedure for amine-functionalized UiO-66 is implemented, which leads to the development of a novel flow-through metal-organic framework synthesis process. Products are characterized via BET modeling of N 2 adsorption at 77 K and powder XRD to confirm crystal porosity and phase, respectively. Batch syntheses are conducted to examine the effects of polytetrafluoroethylene and glass vessel materials on crystal yield and quality. Intermediate samples from sealed-vessel trials at 373, 383, and 393 K are collected and characterized, which show a high degree of product consistency. Nucleation rates are determined at the same temperatures, and the Arrhenius relationship is used to predict the activation energy of nucleation, E aNuc . A continuous-flow reactive crystallization process is developed using a draft-tube type reactor. As a proof of concept, the reactor is operated for three retention times. The cumulative product, material retained within the crystallizer, and intermediate samples are collected and characterized to confirm UiO-66-NH 2 production.

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Section: Introductionmentioning

confidence: 99%

Kinetics study and crystallization process design for scale‐up of UiO‐66‐NH₂ synthesis

et al. 2012

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“…It should be noted that the presence of disordered terephthalic acid, as a major impurity, reduces the relative crystallinity of the final product because of differences in crystal structure of MIL-53(Al) before and after BDC removal. Loiseau et al (2004) reported that heating to 548-693 K can remove the unreacted BDC from the framework of MIL-53(Al) and decomposition of MIL-53(Al) occurs at temperature above 773 K. At high level of calcination temperature (673 K), which is near the sublimation temperature of BDC (675 K) (Lucchesi and Lewis, 1968), hot air stream removed most of the unreacted terephthalic acid from structure of the synthesis material without structural collapse of the framework.…”

Section: Resultsmentioning

confidence: 99%

Study of synthesis parameters of MIL-53(Al) using experimental design methodology for CO₂/CH₄ separation

Taheri¹,

Babakhani²,

Towfighi

2017

Adsorption Science & Technology

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In this study hydrothermal method was used to synthesize MIL-53(Al) (MIL stands for Materials Institute of Lavoisier). Plackett-Burman (P-B) as an experimental design method was applied to investigate the effect of synthesis and activation conditions on specific surface area, relative crystallinity, and production yield of MIL-53(Al) synthesis. Some parameters such as ligand-to-metal molar ratio, synthesis time, synthesis temperature, calcination temperature, and calcination time were selected as the variables. The Brunauer-Emmett-Teller (BET) technique was used in order to estimate the specific surface area of samples while the relative crystallinity of the samples was estimated by comparing their X-Ray Diffraction (XRD) pattern. The morphology of the samples was investigated by field emission scanning electron microscopy. The yield of final products was determined based on organic ligands. The results revealed the significant effect of synthesis temperature on BET surface area, particle size, yield, and crystallinity. The calcination temperature has significant positive effect on BET and crystallinity. Also, the negative significant effect of molar ratio on yield was concluded from the results. However, negligible effect of synthesis and calcination time on the properties of prepared materials were observed. Furthermore, separation capability of a selected sample for carbon dioxide (CO 2 ) and methane (CH 4 ) was measured. Pure gas adsorption data were successfully fitted to Langmuir, Sips, and Toth models. The selected sample provided high adsorption capacity for both gases. The binary adsorption of gases was also investigated based on extended Langmuir equations and the ideal adsorbed solution theory (IAST) models. Comparing the experimental and models data indicated good agreement between the IAST model and experiments. Finally, high CO 2 /CH 4 selectivity of 7.6 was obtained experimentally for the CO 2 /CH 4 molar ratio of 0.2/0.8.

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“…The analysis showed a gradual decomposition process, whereas the main gas components were identified, as follows: 1,3 butadiene, terephthalic ester, benzoic acid, carbon monoxide (CO), carbon dioxide (CO 2 ), tetrahydrofuran (THF), 1,4-butanediol, diethylphosphinic acid, and butanediol. Terephthalic acid mostly condensed in the transfer line due to a high sublimation point at 402 • C and could, therefore, not be found in the gas phase [28]. An overview with the characteristic wavelengths is given in Table 4.…”

Section: Gas Analysismentioning

confidence: 99%

“…As a second possibility also caused by H-shifts within the ester group diols can be formed, which convert to tetrahydrofuran (-H 2 O) and butadiene (-2H 2 O) under the elimination of water. Apart from thermal decomposition, the hydrolysis of PBT occurs, not only based on the water solved in PBT, but also due to the water that formed during the decomposition of PBT [16,28]. The release of water by boehmite at the beginning of pyrolysis enhances the hydrolysis and, thus, the formation of THF.…”

Section: Gas Analysismentioning

confidence: 99%

Particle Size Related Effects of Multi-Component Flame-Retardant Systems in poly(butadiene terephthalate)

et al. 2020

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Aluminum tris-(diethylphosphinate) (AlPi) is known to have an efficient flame-retardant effect when used in poly(butadiene terephthalates) (PBT). Additionally, better flame-retardant effects can be achieved through the partial substitution of AlPi by boehmite in multi-component systems, which have been shown to be an effective synergist due to cooling effects and residue formation. Although the potential of beneficial effects is generally well known, the influence of particle sizes and behavior in synergistic compositions are still unknown. Within this paper, it is shown that the synergistic effects in flammability measured by limiting oxygen index (LOI) can vary depending on the particle size distribution used in PBT. In conducting thermogravimetric analysis (TGA) measurements, it was observed that smaller boehmite particles result in slightly increased char yields, most probably due to increased reactivity of the metal oxides formed, and they react slightly earlier than larger boehmite particles. This leads to an earlier release of water into the system enhancing the hydrolysis of PBT. Supported by Fourier transformation infrared spectroscopy (FTIR), we propose that the later reactions of the larger boehmite particles decrease the portion of highly flammable tetrahydrofuran in the gas phase within early burning stages. Therefore, the LOI index increased by 4 vol.% when lager boehmite particles were used for the synergistic mixture.

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Latent heat of sublimation of terephthalic acid from differential thermal analysis data

Cited by 24 publications

References 4 publications

Kinetics study and crystallization process design for scale‐up of UiO‐66‐NH₂ synthesis

Kinetics study and crystallization process design for scale‐up of UiO‐66‐NH₂ synthesis

Study of synthesis parameters of MIL-53(Al) using experimental design methodology for CO₂/CH₄ separation

Particle Size Related Effects of Multi-Component Flame-Retardant Systems in poly(butadiene terephthalate)

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Latent heat of sublimation of terephthalic acid from differential thermal analysis data

Cited by 24 publications

References 4 publications

Kinetics study and crystallization process design for scale‐up of UiO‐66‐NH2 synthesis

Kinetics study and crystallization process design for scale‐up of UiO‐66‐NH2 synthesis

Study of synthesis parameters of MIL-53(Al) using experimental design methodology for CO2/CH4 separation

Particle Size Related Effects of Multi-Component Flame-Retardant Systems in poly(butadiene terephthalate)

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Product

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Kinetics study and crystallization process design for scale‐up of UiO‐66‐NH₂ synthesis

Kinetics study and crystallization process design for scale‐up of UiO‐66‐NH₂ synthesis

Study of synthesis parameters of MIL-53(Al) using experimental design methodology for CO₂/CH₄ separation