Photocurable Epoxy Acrylate Coatings Preparation by Dual Cationic and Radical Photocrosslinking

Bednarczyk, Paulina; Mozelewska, Karolina; Nowak, Małgorzata; Czech, Zbigniew

doi:10.3390/ma14154150

Cited by 21 publications

(36 citation statements)

References 37 publications

(39 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…39 Omnirad 808 is a free radical photoinitiator composed of bis(2,4,6-trimethylbenzoyl)phenylphosphine oxide (Figure 1B) with purity of 99% and melting point 127-133 C, as stated by its manufacturer. 40 Figure 2 shows a simple general mechanism of free radical polymerization 8,37,[41][42][43][44][45][46][47] for the epoxy diacrylate system used. In fact, there are copolymerization of two monomers (due to the presence of the 25 wt% of tripropylene glycol diacrylate).…”

Section: Methodsmentioning

confidence: 99%

Photoacoustic spectroscopy applied in the monitoring of photocuring process in epoxy diacrylate resins: Positive effect

Borges

Moraes

Neto

et al. 2022

Polymers for Advanced Techs

View full text Add to dashboard Cite

The main goal of this study is to show that photoacoustic spectroscopy (PAS) can be applied in the monitoring of photocuring processes in epoxy diacrylate resins. The resin used was EBECRYL 3720‐TP25 with the photoinitiator Omnirad 808. Comparison between the conventional transmission and absorption photoacoustic spectra of the resin is presented. Amplitude and phase of the photoacoustic signal were used to monitor the photocuring. The wavelength of the modulated photocuring light and the concentration of the photoinitiator were the parameters varied in the monitoring. The novelty was found when the resin was irradiated by a continuous light, centered at the absorption peak of the photoinitiator and simultaneously with the modulated light. In the time window when this continuous light was on (off) the amplitude of the photoacoustic signal increased (decreased). This is called “positive effect,” as it has been observed when PAS was applied to study photosynthesis in leaves. A mechanism is proposed to correlate the positive effect with the oxygen inhibition effect during the photocuring of the epoxy diacrylate resin. The results suggest that the amplitude of the photoacoustic signal and the positive effect can be used as monitoring parameters in the studies of photocuring process in epoxy diacrylate resins.

show abstract

Section: Methodsmentioning

confidence: 99%

Photoacoustic spectroscopy applied in the monitoring of photocuring process in epoxy diacrylate resins: Positive effect

Borges

Moraes

Neto

et al. 2022

Polymers for Advanced Techs

View full text Add to dashboard Cite

show abstract

“…Moreover, it is worth noting that the viscosity of the resin increases substantially with the reaction time (Figure 2c), which also may alter the overall reaction rate. That is to say, systems based on Ep5 and MAA with 50% conversion of epoxy groups are characterized by higher viscosity values when compared to analogous systems based on Ep6 and acrylic acid [33].…”

Section: Synthesis Parameters and Properties Of Obtained Epoxy Methacrylate Resinmentioning

confidence: 95%

Synthesis of Epoxy Methacrylate Resin and Coatings Preparation by Cationic and Radical Photocrosslinking

et al. 2021

Self Cite

View full text Add to dashboard Cite

This work involves the synthesis of hybrid oligomers based on the epoxy methacrylate resin. The EA resin was obtained by the modification of industrial-grade bisphenol A-based epoxy resin and methacrylic acid has been synthesized in order to develop multifunctional resins comprising both epoxide group and reactive, terminal unsaturation. Owing to the presence of both epoxy and double carbon–carbon pendant groups, the reaction product exhibits photocrosslinking via two distinct mechanisms: (i) cationic ring-opening polymerization and (ii) free radical polymerization. Monitoring of EA synthesis reactions over time using PAVs, MAAC and NV parameters, and the FT-IR method reveals that esterification reactions proceed faster at the start, exhibiting over 40% of conversion within the initial 60 min, which can be associated with a relatively high concentration of reactive sites and low viscosity of the reaction mixture at the initial reaction stage. With the further increase in the reaction time, the reaction rate tends to decrease. The control of the EA synthesis process can guide how to adjust reactions to obtain EAs with desired characteristics. Based on obtained values, one can state that the optimum synthesis time of about 4–5 h should be adopted to prepare EAs having both epoxy groups and unsaturated double bonds. The structure of the obtained EA was confirmed by FT-IR and NMR methods, as well as the determination of partial acid value and epoxy equivalent. Samples at various stages of synthesis were cured with UV radiation in order to study the kinetics of the process according to cationic and radical polymerization determined via photo-differential scanning calorimetry (photo-DSC) and real-time infrared spectroscopy (RT-IR) and then the properties of the cured coatings were tested. It turned out that the cationic polymerization was slower with a lower conversion of the photoreactive groups, as compared to the radical polymerization. All the obtained EA coatings were characterized by good properties of cured coatings and can be successfully used in the coating-forming sector.

show abstract

“…It cannot be overlooked that EA pre-polymers with both epoxy and vinyl end-groups can polymerize via two different polymerization mechanisms—cationic or radical [ 1 , 10 , 25 , 26 , 27 , 28 ]. Using a suitable photoinitiator, the photopolymerization mechanism can obtain polymers of various structures, types, and properties from the same pre-polymer.…”

Section: Introductionmentioning

confidence: 99%

Synthesis of Hybrid Epoxy Methacrylate Resin Based on Diglycidyl Ethers and Coatings Preparation via Cationic and Free-Radical Photopolymerization

Bednarczyk

Irska

Gziut

et al. 2022

IJMS

Self Cite

View full text Add to dashboard Cite

A series of difunctional epoxy methacrylate resins (EAs) containing at least one epoxy and at least one methacrylate group were synthesized by means of an addition reaction between epoxy-terminated diglycidyl ethers and methacrylic acid. In order to investigate the impact of polymer architecture on the course of addition reactions and further coating properties, several different types of diglycidyl ethers, i.e., linear, containing aliphatic or aromatic rings, with a short or polymeric backbone, were employed in the synthesis. The carboxyl–epoxide addition esterification reactions have been found to, in a relatively straightforward manner, control the extent of acrylation depending on the substrate feed ratio and reaction time. The structure of obtained pre-polymers was evaluated by FT-IR and NMR methods. At the same time, the extent of addition reactions was validated via quantitative analysis, including non-volatile matter content (NV), acid value (PAVs), and epoxy equivalent value (EE) analysis. The modification was carried out in a manner likely to create a compound with one epoxy and one carbon–carbon pendant group. Hence, due to the presence of both functionalities, it is possible to crosslink compositions based on synthesized EAs via two distinct mechanisms: (i) cationic polymerization or (ii) free-radical polymerization. Synthesized epoxy methacrylate pre-polymers were further employed for use in formulate photocurable coating compositions by the cationic or radical process. Furthermore, the photopolymerization behavior and properties of cured coatings were explored regarding some structural factors and parameters. The investigated polymeric materials cure in a short time to obtain coatings with good properties, which is why they can be successfully used to produce protective and decorative coatings for many industries.

show abstract

Photocurable Epoxy Acrylate Coatings Preparation by Dual Cationic and Radical Photocrosslinking

Cited by 21 publications

References 37 publications

Photoacoustic spectroscopy applied in the monitoring of photocuring process in epoxy diacrylate resins: Positive effect

Photoacoustic spectroscopy applied in the monitoring of photocuring process in epoxy diacrylate resins: Positive effect

Synthesis of Epoxy Methacrylate Resin and Coatings Preparation by Cationic and Radical Photocrosslinking

Synthesis of Hybrid Epoxy Methacrylate Resin Based on Diglycidyl Ethers and Coatings Preparation via Cationic and Free-Radical Photopolymerization

Contact Info

Product

Resources

About