Free-Radical Photopolymerization for Curing Products for Refinish Coatings Market

Abstract

Even though there are many photocurable compositions that are cured by cationic photopolymerization mechanisms, UV curing generally consists of the formation of cross-linking covalent bonds between a resin and monomers via a photoinitiated free radical polymerization reaction, obtaining a three-dimensional polymer network. One of its many applications is in the refinish coatings market, where putties, primers and clear coats can be cured faster and more efficiently than with traditional curing. All these products contain the same essential components, which are resin, monomers and photoinitiators, the latter being the source of free radicals. They may also include additives used to achieve a certain consistency, but always taking into account the avoidance of damage to the UV curing—for example, by removing light from the innermost layers. Surface curing also has its challenges since it can be easily inhibited by oxygen, although this can be solved by adding scavengers such as amines or thiols, able to react with the otherwise inactive peroxy radicals and continue the propagation of the polymerization reaction. In this review article, we cover a broad analysis from the organic point of view to the industrial applications of this line of research, with a wide current and future range of uses.

Chain Walking in the AlCl3Catalyzed Cationic Polymerization of α‐Olefins

“…However, its interest is due to the fact that it can lead to (hyper)branched/dendritic hydrocarbon polymers [24] that are tuned depending on the nature of the catalyst, [25,26,27,28,29] leading to stereospecific polymers, [28] or/with the complexity that the process involves the formation of radical species, [30] and this is also called radical ethene polymerization. [31,32,33] In addition, changing parameters such as monomer concentration or temperature can then block copolymerization. [34,35,36,37,38,39] In the previous research on this topic, some remarkable properties were identified for the PAOs synthesized from the AlCl 3 /solvent system, however the mechanism of chain initiation, propagation and transfer was not clearly determined.…”

“…Consequently, CW can also be considered as a specific part of intermolecular chain transfers. However, its interest is due to the fact that it can lead to (hyper)branched/dendritic hydrocarbon polymers [24] that are tuned depending on the nature of the catalyst, [25,26,27,28,29] leading to stereospecific polymers, [28] or/with the complexity that the process involves the formation of radical species, [30] and this is also called radical ethene polymerization [31,32,33] . In addition, changing parameters such as monomer concentration or temperature can then block copolymerization [34,35,36,37,38,39] .…”

A Study of the Synthesis and Characterization of New Acrylamide Derivatives for Use as Corrosion Inhibitors in Nitric Acid Solutions of Copper

“…It is possible to use various strategies in the field of polymer coating, ranging from environmentally friendly vegetable oil-based coatings to epoxy acrylates of vegetable origin, as well as biodegradable lignin to engineer the bio–nano interface using multifunctional coordinating polymer coatings. Using ultraviolet light to initiate photochemical reactions is a faster and greener alternative [ 15 ]. Additionally, magnetic nanogels are nanosized magnetic polymer composites with a core–shell structure, consisting of nanosized magnetic nanoparticles encapsulated in polymer gel shells, displaying the controllability of magnetic nanoparticles and the swelling ability of hydrogels.…”

Naphthalene-Based Oxime Esters as Type I Photoinitiators for Free Radical Photopolymerization

“…This kind of polymerization photopolymerization is generally classified into two pathways, (1) the free radical polymerization (FRP) [ 15 ] and (2) the cationic polymerization (CP) [ 16 ]. Among them, FRP had been utilized in an acrylate-based system and many of them were adopted in coatings, adhesions, and photolithography industrial applications [ 15 , 17 ].…”