Synthetic routes to block copolymerization by changing mechanism from cationic polymerization to free radical polymerisation

1994 ◽  
Vol 84 (1) ◽  
pp. 127-136 ◽  
Author(s):  
Yusuf Yagoi ◽  
Gürkan Hizal ◽  
Ayşen Önen ◽  
İErsin Serhatli
Keyword(s):  
Free Radical ◽  
Cationic Polymerization ◽  
Block Copolymerization ◽  
Radical Polymerisation ◽  
Synthetic Routes

scholarly journals Recent Advances in bis-Chalcone-Based Photoinitiators of Polymerization: From Mechanistic Investigations to Applications

Molecules ◽  
2021 ◽  
Vol 26 (11) ◽  
pp. 3192
Author(s):  
Nicolas Giacoletto ◽  
Frédéric Dumur
Keyword(s):  
Free Radical ◽  
Radical Polymerization ◽  
Cationic Polymerization ◽  
Free Radical Polymerization ◽  
Research Field ◽  
4D Printing ◽  
Unique Structure ◽  
The Past ◽  
Mechanistic Investigations ◽  
Active Research

Over the past several decades, photopolymerization has become an active research field, and the ongoing efforts to develop new photoinitiating systems are supported by the different applications in which this polymerization technique is involved—including dentistry, 3D and 4D printing, adhesives, and laser writing. In the search for new structures, bis-chalcones that combine two chalcones’ moieties within a unique structure were determined as being promising photosensitizers to initiate both the free-radical polymerization of acrylates and the cationic polymerization of epoxides. In this review, an overview of the different bis-chalcones reported to date is provided. Parallel to the mechanistic investigations aiming at elucidating the polymerization mechanisms, bis-chalcones-based photoinitiating systems were used for different applications, which are detailed in this review.

A Visible Light Initiating System for Free Radical Promoted Cationic Polymerization

1994 ◽  
Vol 27 (14) ◽  
pp. 3683-3693 ◽  
Author(s):  
Yubai Bi ◽  
Douglas C. Neckers
Keyword(s):  
Free Radical ◽  
Visible Light ◽  
Cationic Polymerization

Mechanochemical Reactions Leading to Reinforcement in Rubbers

1960 ◽  
Vol 33 (4) ◽  
pp. 929-939
Author(s):  
R. J. Ceresa
Keyword(s):  
Free Radicals ◽  
Free Radical ◽  
Covalent Bond ◽  
Vinyl Monomers ◽  
Research Association ◽  
Block Copolymerization ◽  
Wide Range ◽  
Carbon Gel ◽  
Internal Mixer ◽  
Mechanochemical Reactions

Abstract The development of the single rotor internal mixer (at the British Rubber Producers' Research Association) has facilitated the research into mechanochemical reactions of a wide range of high polymers. The term “mechanochemical” has been applied to reactions such as mastication, the mechanism of which involves the primary step of mechanical scission of a polymer chain into polymeric free radicals at a carbon to carbon or other covalent bond. The processes which have been studied previously include the cold mastication of rubberlike polymers, the formation of carbon gel, the interpolymerization of two elastomers during blending, and block copolymerization by the cold mastication of polymers plasticized by vinyl monomers. The evidence for the polymeric free radical nature of these reactions has recently been reviewed.

Design and Preparation of Synthetic Hydrogels by Redox Initiation via Free Radical Polymerisation for Biomedical Use as Wound Dressings

2012 ◽  
Vol 506 ◽  
pp. 315-318 ◽  
Author(s):  
C. Witthayaprapakorn ◽  
Robert Molloy
Keyword(s):  
Aqueous Solution ◽  
Free Radical ◽  
Transmission Rate ◽  
Ferrous Sulphate ◽  
Wound Dressings ◽  
Redox Initiation ◽  
Degree Burn ◽  
Radical Polymerisation ◽  
Moist Environment ◽  
Synthetic Hydrogels

Design and preparation of synthetic hydrogels for biomedical use as wound dressings were studied. A partially hydrated hydrogel of sodium salt of 2-acrylamido-2-methylpropanesulfonic acid (Na-AMPS) was prepared by redox initiation via free radical polymerisation in aqueous solution. In this reaction, of 40% w/v Na-AMPS aqueous solution was prepared, with 1.0% by mole of monomer ethylene glycol dimethacrylate (EGDM) as crosslinker, and potassium persulfate (K2S2O8) as the free radical initiator at a concentration of 0.5% mol monomer with potassium metabisulfite (K2S2O5) and ferrous sulphate (FeSO4) as coinitiator. The results showed that the hydrogel sheets gave good coherency, transparency, flexibility, high oxygen permeability, good skin adhesion and were non-toxic. The water properties of the hydrogel sheets (absorption, retention, water vapour transmission rate) were balanced which can maintain the moist environment of the wound. It is concluded that Na-AMPS hydrogels have properties which show potential for biomedical use as a wound dressing for second degree burn.

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