The Philosophy of W. V. Quine

Kaminsky, Jack

doi:10.5840/intstudphil198719119

Cited by 5 publications

(12 citation statements)

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Section: Introductionmentioning

confidence: 99%

“…World production of PMMA is expected to reach 2.85x10 6 tons by 2020, growing at a compound annual growth rate of 6.1% from 2013 to 2020 [5], and as an environmentallyfriend polymer, PMMA is a recyclable material [5][6][7][8]. Over the years, plastics wastes were commonly dumped in a landfill or incinerated for energy recovery [8]. However, in the last decades, the global plastics production increased from 10 8 tons in 1989 to 3.35x10 8 tons in 2016 [9], resulting in increased waste streams [8][9].…”

Section: Introductionmentioning

confidence: 99%

“…Over the years, plastics wastes were commonly dumped in a landfill or incinerated for energy recovery [8]. However, in the last decades, the global plastics production increased from 10 8 tons in 1989 to 3.35x10 8 tons in 2016 [9], resulting in increased waste streams [8][9]. In 2016, only in Europe, 27.1x10 6 tons of plastic waste were collected, being 31.1% recycled, 41.6% incinerated, and 27.3% land filled [9], posing one of the greatest challenges for disposal and recycling of plastic wastes [8].…”

Section: Introductionmentioning

confidence: 99%

“…Most polymers can be pyrolyzed into hydrocarbons (olefins, aromatic and aliphatic compounds) [6]. However, by pyrolysis of polymethyl methacrylate and polystyrene, the main reaction liquid products are their precursor monomers methyl methacrylate (MMA) and styrene [6][7][8]. In this context, pyrolysis, one of the most promising process to convert organic polymers of high molecular weight (macromolecules) into smaller fragments [7], has proven to be an alternative means for depolymerization of polymethyl methacrylate (PMMA) into methyl methacrylate (MMA) [6][7][8], and the literature reports several studies on the subject [6][7][8].…”

Section: Introductionmentioning

confidence: 99%

“…[50] described the progress on reactor technologies for thermal recycling of PMMA [50]. The thermal degradation experiments carried out in micro scale [16,[19][20][21][22][23][24][25][26][27][28][29][30][31][32], bench scale [12,14,17], laboratory [8,11,13,[15][16][17][34][35], and only a few in pilot and/or technical scale [7,11,37,[45][46].…”

Section: Introductionmentioning

confidence: 99%

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Process Analysis of PMMA Dental Resins Scraps Depolimerization: Optimization of Reaction Time and Temperature

Santos¹,

Ribeiro²,

Ferreira³

et al. 2021

Preprint

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In this work, the cross-linked PMMA-based dental resins scraps were submitted to pyrolysis to recover MMA (Methylmethacrylate). The thermal degradation of cross-linked PMMA-based dental resins scraps was analyzed by TG/DTG to guide the operating conditions in pilot scale. The pyrolysis experiments carried out in a reactor of 143L, at 345, 405, and 420°C, 1.0 atmosphere. The reaction liquid products obtained at 345°C, physicochemical characterized for density, kinematic viscosity, and refractive index. The chemical composition of liquid products obtained at 345°C, 30, 40, 50, 60, 70, 80, and 110 minutes, at 405°C, 50, 70, and 130 minutes, and at 420°C, 40, 50, 80, 100, 110, and 130 minutes determined by GC-MS. The experiments show that liquid phase yields were 55.50%, 48.73%, and 48.20% (wt.), at 345, 405, and 420°C, respectively, showing a smooth sigmoid behavior, decreasing with increasing temperature, while that of gas phase were 31.69%, 36.60%, and 40.13% (wt.), respectively, increasing with temperature. The liquid products density, kinematic viscosity, and refractive index obtained at 30, 40, 50, 60, 70, 80, and 110 minutes, varied between 0.9227 and 0.9380 g/mL, 0.566 and 0.588 mm2/s, and 1.401 and 1.414, respectively, showing percentage deviations between 0.74 and 2.36%, 7.40 and 10.86%, and 0.00 and 0.92%, respectively, compared to standard values for density, kinematic viscosity, and refractive index of pure MMA at 20 °C. The GC-MS identified in the reaction liquid products at 345, 405, and 420°C, 1.0 atm, esters of carboxylic acids, alcohols, ketones, and aromatics, showing concentrations of MMA between 83.454 and 98.975% (area.). For all the depolymerization experiments, the concentrations of MMA in the liquid phase, between 30 and 80 minutes, reach purities above 98% (area.), decreasing drastically with increasing reaction time after 100 minutes, thus making it possible to depolymerize the cross-linked PMMA-based dental resins scraps by pyrolysis to recover MMA. The optimum operating conditions to achieve high MMA concentrations, as well as elevated yields of liquid reaction products were 345 °C and 80 minutes.

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Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

Process Analysis of PMMA Dental Resins Scraps Depolimerization: Optimization of Reaction Time and Temperature

Santos¹,

Ribeiro²,

Ferreira³

et al. 2021

Preprint

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Design of Pyroelectric Mixed Crystals Having a Varying Degree of Polarity: The l-Asparagine·H₂O/l-Aspartic Acid System

Belitzky

Weissbuch

Posner-Diskin

et al. 2015

Crystal Growth & Design

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As part of an ongoing program on the design of functional materials with a varying degree of polarity, we investigated the processes of conversion of a nonpolar host, Lasparagine monohydrate crystal (space group P2 1 2 1 2 1 ), into a conglomerate of mixed polar sectors when grown in the presence of varying amounts of L-aspartic acid guest at the glass−aqueous/solution interface. The structure, composition, and the reduction of symmetry of the mixed crystals were confirmed with pyroelectric coefficient measurements, X-ray diffraction, and HPLC analysis and supported by atom−atom potential energy computations. The pyroelectricity measured at the ( 010) and (01̅ 0) faces imply the formation of hybrid crystals with top and bottom parts having opposite polarities. Pyroelectric coefficients measured at these two faces as a function of the occluded guest concentration increase linearly up to 8 wt %/wt of guest, followed by an enhancement of polarity at 8−12 wt %/wt of guest and subsequent reduction upon an increase up to 16 wt %/wt of guest. An interpretation of the magnitude of the pyroelectric effect on guest concentration is proposed.

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Heterogeneous Single-Site Catalysts for Olefin Polymerization

Hlatky¹

2000

Chem. Rev.

768

551

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The Philosophy of W. V. Quine

Cited by 5 publications

References 0 publications

Process Analysis of PMMA Dental Resins Scraps Depolimerization: Optimization of Reaction Time and Temperature

Process Analysis of PMMA Dental Resins Scraps Depolimerization: Optimization of Reaction Time and Temperature

Design of Pyroelectric Mixed Crystals Having a Varying Degree of Polarity: The l-Asparagine·H₂O/l-Aspartic Acid System

Heterogeneous Single-Site Catalysts for Olefin Polymerization

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The Philosophy of W. V. Quine

Cited by 5 publications

References 0 publications

Process Analysis of PMMA Dental Resins Scraps Depolimerization: Optimization of Reaction Time and Temperature

Process Analysis of PMMA Dental Resins Scraps Depolimerization: Optimization of Reaction Time and Temperature

Design of Pyroelectric Mixed Crystals Having a Varying Degree of Polarity: The l-Asparagine·H2O/l-Aspartic Acid System

Heterogeneous Single-Site Catalysts for Olefin Polymerization

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Design of Pyroelectric Mixed Crystals Having a Varying Degree of Polarity: The l-Asparagine·H₂O/l-Aspartic Acid System