Conversion of Poly(methylhydrosiloxane) Waste to Useful Commodities

Döhlert, Peter; Enthaler, Stephan

doi:10.1007/s10562-015-1665-6

Cited by 16 publications

(13 citation statements)

References 36 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…211 Upon treatment with BF3•OEt2, the resulting PDMS byproduct can be recycled into MeSiH3-xFx synthons that are useful building blocks in the silicon industry. 212 Early reports consisted in using Sn salts as activators, [213][214][215] and since then a wider variety of activators, especially in metal-free schemes, has been reported. Nucleophilic activators such as fluorides, 216 phosphines 217 or bases 218 have been successfully applied to PMHS-mediated ketone hydrosilylation (Scheme 20).…”

Section: Pmhsmentioning

confidence: 99%

“…It was first prepared by Sauer and co-worker and has been since reported in a substantial number of reduction processes . Upon treatment with BF 3 ·OEt 2 , the resulting PDMS byproduct can be recycled into MeSiH 3‑x F x synthons that are useful building blocks in the silicon industry . Early reports consisted of using Sn salts as activators, − and since then, a wider variety of activators, especially in metal-free schemes, has been reported.…”

Section: Hydrogen Sourcesmentioning

confidence: 99%

See 1 more Smart Citation

Carbonyl Reduction and Biomass: A Case Study of Sustainable Catalysis

Moores

2019

ACS Sustainable Chem. Eng.

View full text Add to dashboard Cite

Catalysis plays a major role at mitigating the environmental impact of the chemical industry, drastically cutting its energy and material consumption. For this perspective, we have chosen C=O reduction in the context of biomass as a benchmark reaction to introduce and illustrate essential aspects of green catalysis. We first covered the most used C=O hydrogenation substrates made from biomass. Then, we looked at alternative energy sources to convective heating, discussed the use of greener solvents and reductants, and listed a few precious metalfree catalytic systems. Finally we looked at various hydrogen sources, including bio-sourced ones. In particular, we emphasized the use of metrics in order to quantify the actual impact of these innovations.

show abstract

Section: Pmhsmentioning

confidence: 99%

Section: Hydrogen Sourcesmentioning

confidence: 99%

Carbonyl Reduction and Biomass: A Case Study of Sustainable Catalysis

Moores

2019

ACS Sustainable Chem. Eng.

View full text Add to dashboard Cite

show abstract

“…20,21 The same group also reported the use of poly(methylhydrosiloxane) in H 2 evolution by methanolysis, deoxygenation of sulfoxides to sulfides, and hydrodeoxygenation of fatty esters to hydrocarbons, prior to the depolymerization procedure described above. 22 The depolymerization of polysilazanes with BF 3 OEt 2 gave only Me 2 SiF 2 . 23 Despite their high functionality, these methods have drawbacks, e.g., the high cost of fluorinated depolymerization agents and the formation of significant amounts of aromatic organic waste.…”

Section: ■ Introductionmentioning

confidence: 99%

“…They used benzoyl fluoride, boron trifluoride dietherate, a fatty acid anhydride, or combinations of benzoyl chloride or benzoic anhydride with KF to synthesize fluorosilane and fluorodisiloxane derivatives of Me 2 SiF 2 and (Me 2 SiF) 2 O for linear polymers, and Me 2 SiF 2 and SiF 4 for branched polymers. − The obtained fluorinated compounds are attractive starting materials and can be easily polymerized in the presence of H 2 O and NaOH to produce new silicones and NaF . Depolymerization methods were also developed in which catalytic amounts of FeCl 3 or ZnX 2 (X = acac, OAc, or OTf) were used. , The same group also reported the use of poly(methylhydrosiloxane) in H 2 evolution by methanolysis, deoxygenation of sulfoxides to sulfides, and hydrodeoxygenation of fatty esters to hydrocarbons, prior to the depolymerization procedure described above . The depolymerization of polysilazanes with BF 3 OEt 2 gave only Me 2 SiF 2 .…”

Section: Introductionmentioning

confidence: 99%

Solvothermal Alcoholysis Method for Recycling High-Consistency Silicone Rubber Waste

et al. 2021

View full text Add to dashboard Cite

In this work, we investigated the potential use of high-consistency silicone rubber (SR), which is a synthetic solid material used in numerous industrial applications, to produce a range of liquid alkoxysiloxane derivatives R(OSiMe2) x OR, with x = 1 (P 1 ), 2 (P 2 ), 3 (P 3 ), and 4 (P 4 ). We describe a simple and convenient solvothermal alcoholysis method for the chemical recycling of post-consumer SR in the presence of fatty alcohols under catalyst-free or catalytic conditions. This process proceeds easily both without and with a catalyst. Alkali-metal aryloxides supported by a methylsalicylato ligand (MesalO) gave the highest conversions of SR to products P 1 –P 4 . Magnesium and zinc aryloxides enabled efficient conversions of products P 2 –P 4 to P 1 . Binary metal catalysts of general formula [M2M′2(MesalO)6] (M = Mg or Zn; M′ = Li, Na, or K), which had a combination of the catalytic properties shown by alkali-metal aryloxides and magnesium/zinc aryloxides, were produced and used to synthesize P 1 –P 4 . The results show that magnesium–sodium/potassium aryloxides had the best catalytic activities. Their use led to the formation of two dominant products, namely, P 1 and P 2 , with conversion yields of 79 and 17%, respectively. Particular emphasis is placed on the operating conditions and high activity of the catalyst used. Key factors that affect the catalytic activity and reaction mechanism are also highlighted.

show abstract

“…In contrast, silanes can be considered as one of the most inexpensive and environmentally friendly hydride donors. Of the many available silanes, polymethylhydrosiloxane (PMHS), a plentiful and green byproduct of the silicone industry, is a very attractive option . In this context, although homogeneous catalytic systems for the deoxygenation of aromatic alcohols, aldehydes, and ketones with PMHS have been developed, heterogeneous catalytic systems remain limited .…”

Section: Introductionmentioning

confidence: 99%

Room Temperature Chemoselective Deoxygenation of Aromatic Ketones and Aldehydes Promoted by a Tandem Pd/TiO₂ + FeCl₃ Catalyst

et al. 2018

View full text Add to dashboard Cite

A rapid and practical protocol for the chemoselective deoxygenation of various aromatic ketones and aldehydes was described, which used a tandem catalyst composed of heterogeneous Pd/TiO + homogeneous FeCl with the green hydrogen source, polymethylhydrosiloxane (PMHS). The developed catalytic system was robust and scalable, as exemplified by the deoxygenation of acetophenone, which was performed on a gram scale in an atmospheric environment utilizing only 0.4 mol % Pd/TiO + 10 mol % FeCl catalyst to give the corresponding ethylbenzene in 96% yield within 10 min at room temperature. Furthermore, the Pd/TiO catalyst was shown to be recyclable up to three times without an observable decrease in efficiency and it exhibited low metal leaching under the reaction conditions. Insights toward the reaction mechanism of Pd-catalyzed reductive deoxygenation for aromatic ketones and aldehydes were investigated through operando IR, NMR, and GC-MS techniques.

show abstract

Conversion of Poly(methylhydrosiloxane) Waste to Useful Commodities

Cited by 16 publications

References 36 publications

Carbonyl Reduction and Biomass: A Case Study of Sustainable Catalysis

Carbonyl Reduction and Biomass: A Case Study of Sustainable Catalysis

Solvothermal Alcoholysis Method for Recycling High-Consistency Silicone Rubber Waste

Room Temperature Chemoselective Deoxygenation of Aromatic Ketones and Aldehydes Promoted by a Tandem Pd/TiO₂ + FeCl₃ Catalyst

Contact Info

Product

Resources

About

Conversion of Poly(methylhydrosiloxane) Waste to Useful Commodities

Cited by 16 publications

References 36 publications

Carbonyl Reduction and Biomass: A Case Study of Sustainable Catalysis

Carbonyl Reduction and Biomass: A Case Study of Sustainable Catalysis

Solvothermal Alcoholysis Method for Recycling High-Consistency Silicone Rubber Waste

Room Temperature Chemoselective Deoxygenation of Aromatic Ketones and Aldehydes Promoted by a Tandem Pd/TiO2 + FeCl3 Catalyst

Contact Info

Product

Resources

About

Room Temperature Chemoselective Deoxygenation of Aromatic Ketones and Aldehydes Promoted by a Tandem Pd/TiO₂ + FeCl₃ Catalyst