Chemical degradation of bisphenol A diglycidyl ether/methyl tetrahydrophthalic anhydride networks by p-Toluenesulfonic-acetic anhydride

Lei, Yan-Qun; He, Zhao-Xia; Yan, Luo; Lu, Shao-Ning; Li, Chun-Jia

doi:10.1016/j.polymdegradstab.2015.11.010

Cited by 11 publications

(5 citation statements)

References 15 publications

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“…On the other hand, the embedded CFs or precious metals are prone to be harmed by high temperature and strong chemicals. Several recycling methods were investigated, including mechanical, , thermal (or pyrolysis), , and chemical approaches. − The chemical recycling approach is among the most promising ones since the filling matters, such as continuous long CFs together with valuable building blocks of the epoxy resin can be recycled in the same process. However, conventional methods of chemically recycling high-performance epoxy thermosets may involve strong chemicals or high pressure and relatively high temperature (>200 °C) for a long time. , These issues limited the large-scale applications of industrial thermosets and composites recycling.…”

Section: Introductionmentioning

confidence: 99%

Recycling of Epoxy Thermoset and Composites via Good Solvent Assisted and Small Molecules Participated Exchange Reactions

Xiao

Zhou

Shi

et al. 2018

ACS Sustainable Chem. Eng.

192

136

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Thermosetting polymers and composites are a class of high-performance materials with significant industrial applications. However, recycling of thermosets and their filling matters are significantly challenging. Here, we propose a method to recycle epoxy thermosetting polymer and composites efficiently by a synergistic effect of a solvent mixture using a highly efficient organic catalyst at an ordinary pressure and mild temperatures. The anhydrideepoxy network depolymerization enabled by selective ester bond cleavage process is substantially enhanced by a good solvent assisted and alcohol participated transesterification reaction. The epoxy thermoset can be dissolved in 28 min with 50% mass loss, and 70 min with 95% mass loss at 170 °C under ambient pressure. We demonstrate that this method can be used to reclaim carbon fibers from industrial reinforced epoxy composite products and embedded metal parts from commercial electronic products with undiminished properties at a mild temperature (∼170 °C) under an ordinary pressure in a short time (1.5 h). Moreover, the decomposed epoxy oligomer can be reused as a reactive ingredient for the preparation of new epoxy materials with high strength and modulus. This work provides a new insight into the thermosets dissolution and recycling.

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Section: Introductionmentioning

confidence: 99%

Recycling of Epoxy Thermoset and Composites via Good Solvent Assisted and Small Molecules Participated Exchange Reactions

Xiao

Zhou

Shi

et al. 2018

ACS Sustainable Chem. Eng.

192

136

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“…Peak 1 represents the graphite peak (C–C) with a binding energy of 284.6 eV; peak 2 represents C–OH with a binding energy of 286.0 eV; peak 3 is C=O with a binding energy of 287.5 eV; and peak 4 is C=O representing –COOH and –COOR with a binding energy of 288.9 eV [ 28 , 29 , 30 ]. A small peak is observed near 288 eV in the C1s spectrum, indicating the existence of an O–C=O bond [ 44 , 45 , 46 ]. With increasing PA concentration, the interfacial shear strength of the carbon fiber samples increased because the strong oxidizing ability of PA in aqueous solution promoted the formation of oxygen-containing functional groups on the surface of the carbon fiber, thus improving the surface activity of the carbon fiber and enhancing the binding capacity between the carbon fiber and the test microdroplets.…”

Section: Resultsmentioning

confidence: 99%

“…The weakly coordinating HPA n− ions coordinated the isolated electron pair of the nitrogen atoms. During the electrochemical process, the now more electrophilic tertiary carbon was attacked, which led to cleavage of the bond between the tertiary carbon and the nitrogen [ 45 , 50 , 59 ] and resulted in the formation of BPA and ethane diamine (see Figure 7 ).…”

Section: Resultsmentioning

confidence: 99%

Orthogonal Experimental Analysis and Mechanism Study on Electrochemical Catalytic Treatment of Carbon Fiber-Reinforced Plastics Assisted by Phosphotungstic Acid

2020

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Preserving the integrity of carbon fibers when recycling carbon-fiber-reinforced plastics (CFRPs) has been unfeasible due to the harsh reaction conditions required to remove epoxy resin matrixes, which adversely affect the properties of carbon fibers. We establish a practicable and environmentally friendly reclamation strategy for carbon fibers. Carbon fibers are recycled from waste CFRPs by an electrochemical catalytic reaction with the assistance of phosphotungstic acid (PA), which promotes the depolymerization of diglycidyl ether of bisphenol A/ethylenediamine (DGEBA/EDA) epoxy resin. The removal rate, mechanical strength, and microstructure of the recycled carbon fibers are analyzed to explore the mechanism of the electrochemical treatment. The influence of three factors—current density, PA concentration, and reaction time—are studied via an orthogonal method. Range analysis and variance analysis are conducted to investigate the significance of the factors. The optimal conditions are determined accordingly. The underlying CFRP degradation mechanism is also investigated.

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“…The synthesis of C 12 EO 7 S was composed of three parts starting with AEO. The average molecular weight of AEO was determined by the hydroxyl value using the mixed p‐toluenesulfonic‐acetic anhydride method (Lei et al, ). The acylation reaction between hydroxyl and acetic anhydride generate acetic acid, and the produced acetic acid quantity was determined by standard KOH solution using cresol red and thymol blue indicators.…”

Section: Methodsmentioning

confidence: 99%

Synthesis of an Alkyl Polyoxyethylene Ether Sulfonate Surfactant and Its Application in Surfactant Flooding

Tang

et al. 2018

J Surfact & Detergents

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Surfactant flooding as a potential enhanced oil‐recovery technology in a high‐temperature and high‐salinity oil reservoir after water flooding has attracted extensive attention. In this study, the synthesis of an alkyl alcohol polyoxyethylene ether sulfonate surfactant (C12EO7S) with dodecyl alcohol polyoxyethylene ether and sodium 2‐chloroethanesulfonate monohydrate, and its adaptability in surfactant flooding were investigated. The fundamental parameters of C12EO7S were obtained via surface tension measurement. And the ability to reduce oil–water interfacial tension (IFT), wettability alteration, emulsification, and adsorption was determined. The results illustrated that IFT could be reduced to 10−3 mN m−1 at high temperature and high salinity without additional additives, and C12EO7S exhibited benign wettability alternate ability, and emulsifying ability. Furthermore, the oil‐displacement experiments showed that C12EO7S solution could remarkably enhance oil recovery by 16.19% without adding any additives.

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Chemical degradation of bisphenol A diglycidyl ether/methyl tetrahydrophthalic anhydride networks by p-Toluenesulfonic-acetic anhydride

Cited by 11 publications

References 15 publications

Recycling of Epoxy Thermoset and Composites via Good Solvent Assisted and Small Molecules Participated Exchange Reactions

Recycling of Epoxy Thermoset and Composites via Good Solvent Assisted and Small Molecules Participated Exchange Reactions

Orthogonal Experimental Analysis and Mechanism Study on Electrochemical Catalytic Treatment of Carbon Fiber-Reinforced Plastics Assisted by Phosphotungstic Acid

Synthesis of an Alkyl Polyoxyethylene Ether Sulfonate Surfactant and Its Application in Surfactant Flooding

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