scholarly journals SYNTHESIS OF GLYCIDYL AND THIOGLYCIDYL ETHERS OF DIACETYLENE SERIES AND THEIR USE AS A MODIFIER OF PHENOL-FORMALDEHYDE OLIGOMERS

Author(s):  
Makhruza I. Shatirova ◽  
Tamilla M. Naibova

It has been shown that the chlorine-containing unconjugated enyne alcohols react with epichlorohydrin in the presence of boron trifluoride etherate with formation of chlorohydrines, which further without their isolation, under the action of potassium hydrochloride are dehydrochlorinated with formation of the corresponding glycidyl ethers. Under the action of an alcoholic solution of potassium hydroxide at temperature of 75-80 °С on synthesized chlorine-containing ethers the dehydrochlorination reaction on double С=С bond proceeds and glycidyl ethers of 1,4-diine series are formed. It has been revealed that the synthesized glycidyl ethers are the very reactive compounds. In patricular, it has been shown that the ethers of 1,4-diine series with the participation of oxirane ring undergo the reaction with thiurea medium of methanol at 30-35 °С, forming the corresponding tyrants. The data of IR- and NMR-spectra of the prepared compounds have been presented and their modifying properties in relation to phenol-formaldehyde oligomers in acidic and alkaline media have been revealed. The prepared modified oligomers are the products of liquid-viscous consistency, soluble in acetone, tetrahydrofuran, dimethyl formamide and dioxane. It has been proved by the carried out analyses that the prepared PhFOs, modified by glycidyl and thiglycidyl ethers of diacetylene series are not mechanical mixtures of phenol, formaldehyde and modifier. On the basis of obtained results the formation mechanism of modified resol and novolac PhFO has been also revealed. It has been established that the physical-chemical and physical-mechanical parameters of the prepared phenol-formaldehyde oligomers modified by modifiers proposed by us, in comparison with unmodified ones, are improved. From the proposed diglycidyl and thiodiglycidyl ethers for the modification of PhFO the best results on all parameters are achieved at modification with thioglycidyl ether of diacetylene series.

2020 ◽  
Vol 9 (1) ◽  
pp. 843-852
Author(s):  
Hunan Jiang ◽  
Jinyang Li ◽  
Mengni Liang ◽  
Hanpeng Deng ◽  
Zuowan Zhou

AbstractAlthough Fe–N/C catalysts have received increasing attention in recent years for oxygen reduction reaction (ORR), it is still challenging to precisely control the active sites during the preparation. Herein, we report FexN@RGO catalysts with the size of 2–6 nm derived from the pyrolysis of graphene oxide and 1,1′-diacetylferrocene as C and Fe precursors under the NH3/Ar atmosphere as N source. The 1,1′-diacetylferrocene transforms to Fe3O4 at 600°C and transforms to Fe3N and Fe2N at 700°C and 800°C, respectively. The as-prepared FexN@RGO catalysts exhibited superior electrocatalytic activities in acidic and alkaline media compared with the commercial 10% Pt/C, in terms of electrochemical surface area, onset potential, half-wave potential, number of electrons transferred, kinetic current density, and exchange current density. In addition, the stability of FGN-8 also outperformed commercial 10% Pt/C after 10000 cycles, which demonstrates the as-prepared FexN@RGO as durable and active ORR catalysts in acidic media.


2011 ◽  
Vol 381 (1-2) ◽  
pp. 81-89 ◽  
Author(s):  
Mayur Dalwani ◽  
Gerrald Bargeman ◽  
Seyed Schwan Hosseiny ◽  
Marcel Boerrigter ◽  
Matthias Wessling ◽  
...  

RSC Advances ◽  
2016 ◽  
Vol 6 (9) ◽  
pp. 7370-7377 ◽  
Author(s):  
Yang Zhao ◽  
Shuo Wang ◽  
Chunyan Li ◽  
Xianbo Yu ◽  
Chunling Zhu ◽  
...  

MoP/N,P dual-doped carbon nanotube composite exhibited excellent activity and long-term stability toward HER both in acidic and alkaline media, superior to most of catalysts reported previously.


Nanoscale ◽  
2020 ◽  
Vol 12 (28) ◽  
pp. 15115-15127 ◽  
Author(s):  
Meng-geng Hao ◽  
Rong-min Dun ◽  
Yu-miao Su ◽  
Wen-mu Li

MF nanospheres decomposed into NH3 and CO2 as soft templates, nitrogen sources and pore-forming agents.


2020 ◽  
Vol 44 (19) ◽  
pp. 7902-7911
Author(s):  
Le Hu ◽  
Yuyun Sun ◽  
Shi-Jing Gong ◽  
Hui Zong ◽  
Ke Yu ◽  
...  

A composite of MoS2/Nb2CTx with MoS2 nanoflowers grown between Nb2CTx flakes for electrolysis of water in acidic and alkaline solutions.


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