scholarly journals New Pure Organic and Peroxide-Free Redox Initiating Systems for Polymerization in Mild Conditions

Polymers ◽  
2021 ◽  
Vol 13 (2) ◽  
pp. 301
Author(s):  
Ahmad Arar ◽  
Lilian Wisson ◽  
Jacques Lalevée
Keyword(s):  
Free Radical ◽  
Thermal Imaging ◽  
High Performance ◽  
Room Temperature ◽  
High Reactivity ◽  
Light Activation ◽  
Work Time ◽  
Mild Conditions ◽  
Full Control ◽  
Iodonium Salt

Redox initiating systems (RISs) are highly worthwhile for polymerization in mild conditions (at room temperature—RT) without external thermal or light activation. With high performance redox initiating systems RIS, the free radical polymerization FRP can even be carried out under air and without inhibitors/stabilizers removal from the monomers/resins. However, efficient RISs are still based on peroxides or metal complexes. In this work, a pure organic and peroxide-free RIS is presented based on the interaction of a well-selected triarylamine derivative (T4epa) with iodonium salt used as reducing and oxidizing agents, respectively. The redox polymerization (Redox FRP) was followed through pyrometry and thermal imaging experiments. Remarkably, a full control of the work time as well as a high reactivity is observed for mild conditions.

scholarly journals High Performance Redox Initiating Systems Based on the Interaction of Silane with Metal Complexes: A Unique Platform for the Preparation of Composites

Molecules ◽  
2020 ◽  
Vol 25 (7) ◽  
pp. 1602
Author(s):  
Ahmad Arar ◽  
Haifaa Mokbel ◽  
Frédéric Dumur ◽  
Jacques Lalevée
Keyword(s):  
Metal Complexes ◽  
Aromatic Amines ◽  
High Performance ◽  
Room Temperature ◽  
Hazardous Substances ◽  
Gel Time ◽  
Chemical Mechanisms ◽  
Mild Conditions ◽  
Spin Resonance ◽  
Methacrylate Monomers

Currently, Redox Initiating Systems (RISs) of Free Radical Polymerization (FRP) are mainly based on the interaction of aromatic amines with peroxides (e.g., dibenzoyl peroxide (BPO)) that can be both toxic and unstable. In the present work, we aim to replace these hazardous substances in new RIS that can be peroxide-free and amine-free. Our redox two components (2K) initiating system is based on diphenylsilane (DPS) as reducing agent combined with different metal complexes (Mn(acac)2, Cu(AAEMA)2 or Fe(acac)3) as oxidizing agents. For the new proposed RIS, an excellent reactivity is found for the polymerization of benchmark methacrylate monomers under mild conditions (redox polymerization done under air and at room temperature); remarkably, it is also possible to finely control the gel time. Different techniques (optical pyrometry, Real-Time FTIR spectroscopy, Cyclic Voltammetry and Electron Spin Resonance (ESR)) were used to follow the polymerization processes but also to shed some light on the new redox chemical mechanisms.

scholarly journals Development of New High-Performance Biphenyl and Terphenyl Derivatives as Versatile Photoredox Photoinitiating Systems and Their Applications in 3D Printing Photopolymerization Processes

Catalysts ◽  
2019 ◽  
Vol 9 (10) ◽  
pp. 827 ◽  
Author(s):  
Tomal ◽  
Pilch ◽  
Chachaj-Brekiesz ◽  
Ortyl
Keyword(s):  
Free Radical ◽  
High Performance ◽  
Theoretical Calculations ◽  
Polymer Networks ◽  
Electrochemical Analysis ◽  
Type Ii ◽  
Long Wave ◽  
Different Types ◽  
Ft Ir ◽  
Iodonium Salt

Novel 2-amino-4-methyl-6-phenyl-benzene-1,3-dicarbonitrile derivatives were proposed as photosensitizes of iodonium salt for a highly effective bimolecular photoinitiating system upon soft irradiation conditions under long-wave ultraviolet (UV-A) and visible light. Remarkably, these structures are highly versatile, allowing access to photoinitiating systems for the free-radical polymerization of acrylates, the cationic photopolymerization of epoxides, glycidyl, and vinyl ethers, the synthesis of interpenetrated polymer networks (IPNs) and the thiol-ene photopolymerization processes. Excellent polymerization profiles for all of the monomers, along with the high final conversions, were obtained. The initiation mechanisms of these bimolecular systems based on the 2-amino-4-methyl-6-phenyl-benzene-1,3-dicarbonitrile derivatives were investigated using the real-time FT-IR technique, steady-state photolysis, fluorescence experiments, theoretical calculations of molecular orbitals, and electrochemical analysis. Moreover, the 2-amino-4-methyl-6-phenyl-benzene-1,3-dicarbonitrile derivatives were investigated as a type II free-radical photoinitiator with amine. It was confirmed that the 2-amino-4-methyl-6-phenyl-benzene-1,3-dicarbonitrile derivatives, in combination with different types of additives, e.g., amine as co-initiator or in the presence of onium salt, can act as a bimolecular photoinitiating system via the photo-reduction or photo-oxidation pathways, respectively.

scholarly journals Free Radical Photopolymerization and 3D Printing Using Newly Developed Dyes: Indane-1,3-Dione and 1H-Cyclopentanaphthalene-1,3-Dione Derivatives as Photoinitiators in Three-Component Systems

Catalysts ◽  
2020 ◽  
Vol 10 (4) ◽  
pp. 463 ◽  
Author(s):  
Ke Sun ◽  
Corentin Pigot ◽  
Hong Chen ◽  
Malek Nechab ◽  
Didier Gigmes ◽  
...  
Keyword(s):  
Free Radical ◽  
3D Printing ◽  
High Performance ◽  
Chemical Mechanisms ◽  
Esr Spin Trapping ◽  
Free Radical Photopolymerization ◽  
Spin Resonance ◽  
Component Systems ◽  
Iodonium Salt ◽  
First Time

The design of photoinitiating systems with excellent photochemical reactivities at 405nm LED is one of the obstacles to efficiently promote free radical polymerization in mild conditions (e.g., low light intensity, under air). Here, our actual search for new multicomponent photoinitiating systems at 405nm LED prompts us to develop new dyes based on push–pull structures. In the present paper, we chose two series of new dyes which possess indane-1,3-dione and 1H-cyclopenta naphthalene-1,3-dione groups as the electron-withdrawing groups, since they have the great potential to behave as sensitive and remarkable photoinitiators in vat photopolymerization/3D printing. When incorporated with a tertiary amine (ethyl dimethylaminobenzoate EDB, used as electron/hydrogen donor) and an iodonium salt (used as electron acceptor) as the three-component photoinitiating systems (PISs), and among a series of 21 dyes, 10 of them could efficiently promote the free radical photopolymerization of acrylates. Interestingly, steady state photolysis experiments revealed different behaviors of the dyes. Fluorescence experiments and free energy change calculations for redox processes were also carried out to investigate the relevant chemical mechanisms. Additionally, the formation of radicals from the investigated PISs was clearly observed by electron spin resonance (ESR) spin-trapping experiments. Finally, stereoscopic 3D patterns were successfully fabricated by the laser writing technique. In this work, the use of push–pull dyes based on the naphthalene scaffold as photoinitiators of polymerization is reported for the first time in a systematic study aiming at investigating the structure–performance relationship for irradiation carried out at 405 nm. By carefully selecting the electron donors used in the two series of push–pull dyes, novel and high-performance photoinitiating systems operating at 405 nm are thus proposed.

A Convenient Solid-Support Procedure for the Synthesis of Symmetric Disulphides. The Configuration of Aromatic Carben Atoms in the 1,6-Methano[10]annulene Framework

1990 ◽  
Vol 45 (11) ◽  
pp. 1582-1588 ◽  
Author(s):  
Richard Neidlein ◽  
Take Constantinescu ◽  
Claus Krieger ◽  
H.-P. Deigner
Keyword(s):  
Aromatic Ring ◽  
Room Temperature ◽  
High Reactivity ◽  
Solid Support ◽  
Substitution Reactions ◽  
Aromatic Carbon ◽  
X Ray ◽  
Mild Conditions ◽  
Electronic Distribution ◽  
Atomic Coordinates

Treatment of organic thiocyanates with aluminium oxide, at room temperature, is found to afford a convenient procedure for the synthesis of symmetric disulphides, under mild conditions.An X-ray structure analysis of meso-di-(1,6-methano[10]annulen-2-yl)-disulphide (2a) suggests an intermediate sp2—-sp3 hybridization state for the aromatic carbon atoms and a faceasymmetric electronic distribution in the annulene ring. Using reported atomic coordinates, a similar configuration is determined for the parent structure 7. A higher π-electron density on the exo face of the aromatic ring may account for the known syn,syn stereochemical course of electrophilic addition to 7, as well as for the high reactivity of this system towards electrophiles, in addition and in substitution reactions.

Study on Synthesis of Polycarboxylate Superplasticizer at Room Temperature

2014 ◽  
Vol 672-674 ◽  
pp. 688-690
Author(s):  
Gang Wang ◽  
Ling Xun Liang
Keyword(s):  
Free Radical ◽  
High Performance ◽  
Room Temperature ◽  
Deionized Water ◽  
Synthesis Process ◽  
Temperature Synthesis ◽  
Polycarboxylate Superplasticizer ◽  
Production Water ◽  
Save Energy ◽  
The Cost

Use TPEG and AA , Through free radical polymerization in normal temperature conditions, Synthesis of the high-performance polycarboxylate superplasticizer. The results showed that, Room temperature synthesis of polycarboxylate superplasticizer with high temperature (60°C) synthesis of polycarboxylate superplasticizer have same performance. The synthesis process without heating, Production water without deionized water, To save energy, To greatly reduce the cost.

SuFEx Activation with Ca(NTf2)2: A Unified Strategy to Access Sulfamides, Sulfamates and Sulfonamides from S(VI) Fluorides

2020 ◽  
Author(s):  
Subham Mahapatra ◽  
Cristian P. Woroch ◽  
Todd W. Butler ◽  
Sabrina N. Carneiro ◽  
Sabrina C. Kwan ◽  
...  
Keyword(s):  
Room Temperature ◽  
Medicinal Chemistry ◽  
Mild Conditions ◽  
Broad Array

<p><br></p> <p>A method to activate sulfamoyl fluorides, fluorosulfates, and sulfonyl fluorides with calcium triflimide, and DABCO for SuFEx with amines is described. The reaction was applied to a diverse set of sulfamides, sulfamates, and sulfonamides at room temperature under mild conditions. Additionally, we highlight the application of this transformation to parallel medicinal chemistry to generate a broad array of nitrogen-based S(VI) compounds. </p>

SuFEx Activation with Ca(NTf2)2: A Unified Strategy to Access Sulfamides, Sulfamates and Sulfonamides from S(VI) Fluorides

2020 ◽  
Author(s):  
Subham Mahapatra ◽  
Cristian P. Woroch ◽  
Todd W. Butler ◽  
Sabrina N. Carneiro ◽  
Sabrina C. Kwan ◽  
...  
Keyword(s):  
Room Temperature ◽  
Medicinal Chemistry ◽  
Mild Conditions ◽  
Broad Array

<p><br></p> <p>A method to activate sulfamoyl fluorides, fluorosulfates, and sulfonyl fluorides with calcium triflimide, and DABCO for SuFEx with amines is described. The reaction was applied to a diverse set of sulfamides, sulfamates, and sulfonamides at room temperature under mild conditions. Additionally, we highlight the application of this transformation to parallel medicinal chemistry to generate a broad array of nitrogen-based S(VI) compounds. </p>

High Performance Optoelectronic Devices Based on Bright Perovskite Nanocrystals Synthesized at Room Temperature

2018 ◽  
Author(s):  
Sotirios Christodoulou ◽  
Francesco Di Stasio ◽  
Santanu Pradhan ◽  
Inigo Ramiro ◽  
Yu Bi ◽  
...  
Keyword(s):  
High Performance ◽  
Room Temperature ◽  
Optoelectronic Devices ◽  
Perovskite Nanocrystals
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