Recent Advances in Cationic Photopolymerization

Sangermano, Marco

doi:10.2494/photopolymer.32.233

Cited by 20 publications

(11 citation statements)

References 9 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…As an alternative, epoxy resins can be crosslinked by means of UV-light in the presence of onium salts (diaryliodonium or triarylsulfonium); these salts, under irradiation, are able to photogenerate a strong Bronsted acid, which starts the cationic ring-opening polymerization of epoxy monomers. [7][8][9][10][11] The cationic UV-curing of epoxy resins takes place very quickly, compared to the thermal crosslinking process. The main limitation of epoxy UV-curing is the low penetration depth of UV light.…”

Section: Doi: 101002/mame202100495mentioning

confidence: 99%

An Epoxy Adhesive Crosslinked through Radical‐Induced Cationic Frontal Polymerization

Turani

Baggio

Casalegno

et al. 2021

Macro Materials & Eng

Self Cite

View full text Add to dashboard Cite

UV-initiated cationic frontal polymerization is exploited as a solvent-free, extremely fast, and low-temperature technique to obtain epoxy-based adhesives. Epoxy formulations are prepared by blending commercial resins at different weight ratios and adding photo and thermal initiators at different percentages. In addition, the influence of other critical parameters, including the joint thickness, the nature of the adherends, and the temperature, is studied. As the reaction front is thermally sustained, the boundary conditions play a key role during the curing process and heat dissipation through the adherends in particular. The thermal properties of the epoxy formulation are studied through differential scanning calorimetry analysis, and the joint strengths are investigated by carrying out single lap off-set shear tests under compression. The results demonstrate the feasibility of obtaining joints by means of the radical induced cationic frontal polymerization of the epoxy adhesives, which exhibit comparable epoxy group conversion and mechanical performances to the ones cured by traditional energy-intensive techniques. IntroductionEpoxy resins are widely used as high-performance adhesives and coatings in various fields, including the automotive, aerospace, and naval industries. [1][2][3] Traditionally, epoxy-based adhesives are thermally cured in the presence of hardeners, generally, amines or polyfunctional anhydrides, [4] to produce crosslinked thermoset structures characterized by good mechanical properties, good adhesion to the adherends, as well as thermal and chemical resistance. [5] However, thermal curing is a slow process and therefore requires a large amount of energy to maintain appropriate temperatures for the whole processing time. [6]

show abstract

Section: Doi: 101002/mame202100495mentioning

confidence: 99%

An Epoxy Adhesive Crosslinked through Radical‐Induced Cationic Frontal Polymerization

Turani

Baggio

Casalegno

et al. 2021

Macro Materials & Eng

Self Cite

View full text Add to dashboard Cite

show abstract

“…Alkoxypyridinium salts on the other hand have excellent thermal stability and high solubility [ 44 , 45 , 46 , 47 ]. New carbazole scaffold visible light photoinitiator/photosensitizers were recently developed by Lalevée et al These systems consist of a carbazole unit connected at two 4,4′-dimethoxydiphenylamine groups in positions 3 and 6 [ 48 ].…”

Section: Cationic Uv-curingmentioning

confidence: 99%

“…Versace et al have studied the use of anthraquinone functional phthalocyanine in combination with suitable co-initiators as visible light photoinitiator systems for cationic and free-radical polymerization [ 50 ]. The progress in cationic photoinitiators has been in detail analyzed in recent reviews [ 28 , 29 , 45 , 46 , 47 ].…”

Section: Cationic Uv-curingmentioning

confidence: 99%

Cationic UV-Curing of Epoxidized Biobased Resins

2020

Self Cite

View full text Add to dashboard Cite

Epoxy resins are among the most important building blocks for fabrication of thermosets for many different applications thanks to their superior thermo-mechanical properties and chemical resistance. The recent concerns on the environmental problems and the progressive depletion of petroleum feedstocks have drawn the research interest in finding biobased alternatives. Many curing techniques can be used to obtain the final crosslinked thermoset networks. The UV-curing technology can be considered the most environmentally friendly because of the absence of volatile organic compound (VOC) emissions and mild curing conditions. This review provides an overview of the state of the art of bio-based cationic UV-curable epoxy resins. Particular focus has been given to the sources of the bio-based epoxy monomers and the applications of the obtained products.

show abstract

“…In this system, an onium salt with improved electron acceptability is effective. In addition, an application to a light-induced frontal polymerization system for curing of the deep portion that light does not reach has been recently reported [97]. Further, novel photoinitiation systems such as a photoelectron transfer initiation system using upconversion and a photoinitiation system using photoredox catalysts have been proposed [57][58][59].…”

Section: Utilization Of Photo-sensitizersmentioning

confidence: 99%

Recent Progress in Photo-Acid Generators for Advanced Photopolymer Materials

Tsuchimura

2020

J. Photopol. Sci. Technol.

View full text Add to dashboard Cite

Photopolymer materials have been widely used in some advanced industries owing to their practicability, low-cost, and ecological advantage. One of the key components of these photopolymer materials is a molecule that releases acidic species upon a photon trigger (known as Photo-acid generators, PAGs). Recently, PAGs have attracted much attention with novel technologies such as near-infrared CTP imaging, 3D printing, and EUV lithography, and are required to have various functions and sophisticated features. This review article summarizes recent advances in the molecular design and function of PAGs, which are required to respond to the increasing applications of the photopolymer materials in advanced industries.

show abstract

Recent Advances in Cationic Photopolymerization

Cited by 20 publications

References 9 publications

An Epoxy Adhesive Crosslinked through Radical‐Induced Cationic Frontal Polymerization

An Epoxy Adhesive Crosslinked through Radical‐Induced Cationic Frontal Polymerization

Cationic UV-Curing of Epoxidized Biobased Resins

Recent Progress in Photo-Acid Generators for Advanced Photopolymer Materials

Contact Info

Product

Resources

About