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Wärnheim, AlexanderORCID iD iconorcid.org/0000-0001-6438-1357
Publications (4 of 4) Show all publications
Wärnheim, A., Kotov, N., Dobryden, I., Telaretti Leggieri, R., Edvinsson, C., Heydari, G., . . . Claesson, P. M. (2024). Nanomechanical and nano-FTIR analysis of polyester coil coatings before and after artificial weathering experiments. Progress in organic coatings, 190, Article ID 108355.
Open this publication in new window or tab >>Nanomechanical and nano-FTIR analysis of polyester coil coatings before and after artificial weathering experiments
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2024 (English)In: Progress in organic coatings, ISSN 0300-9440, E-ISSN 1873-331X, Vol. 190, article id 108355Article in journal (Refereed) Published
Abstract [en]

Local heterogeneities can have significant effects on the performance of anti-corrosion coatings. Even small features can act as initiation points for damage and result in corrosion of the substrate material. Analysis methods with high spatial resolution and the ability to collect information relevant to crosslinking and degradation behavior of these coatings are therefore highly relevant. In this work, we demonstrate the utility of nanomechanical AFM measurements and nano-FTIR in investigating the nanoscale mechanical and chemical properties of two polyester coil coating clearcoats before and after weathering. On the nanoscale, weathering led to a stiffer and less deformable coating with less variation in the nanomechanical properties. Chemical degradation was quantified using changes in band ratios in the IR-spectra. Macro and nano-scale measurements showed similar trends with the latter measurements showing larger heterogeneity. Our results demonstrate the usefulness of the described analysis techniques and will pave the way for future studies of local properties in other coating systems and formulations. © 2024 The Authors

Place, publisher, year, edition, pages
Elsevier B.V., 2024
Keywords
Corrosion resistant coatings; Crosslinking; Nanotechnology; Weathering; Artificial weathering; Coil coatings; FTIR; FTIR analysis; Local heterogeneity; Nano scale; Nano-FTIR; Nanomechanical; Nanomechanical property; Fourier transform infrared spectroscopy
National Category
Materials Engineering
Identifiers
urn:nbn:se:ri:diva-72754 (URN)10.1016/j.porgcoat.2024.108355 (DOI)2-s2.0-85188822290 (Scopus ID)
Note

This work was supported by the Swedish Foundation for Strategic Research (SSF) grant FID18-0034.

Available from: 2024-05-16 Created: 2024-05-16 Last updated: 2024-05-16Bibliographically approved
Telaretti Leggieri, M. R., Deltin, T., Wärnheim, A., Sundell, P.-E., Malmström, E. & Johansson, M. (2023). Polyester–melamine coil coating formulation reinforced with surface-modified cellulose nanofibrils. Progress in organic coatings, 182, Article ID 107608.
Open this publication in new window or tab >>Polyester–melamine coil coating formulation reinforced with surface-modified cellulose nanofibrils
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2023 (English)In: Progress in organic coatings, ISSN 0300-9440, E-ISSN 1873-331X, Vol. 182, article id 107608Article in journal (Refereed) Published
Abstract [en]

In light of the need to redesign industrially produced materials by utilizing renewable resources, nanoscopic forms of cellulose are regarded as a valuable asset. In this work, the potential of cellulose nanofibrils (CNFs) as an unconventional nanoadditive for a polyester–melamine coil coating formulation is explored. CNFs, hydrophilic nanomaterials with high aspect ratios, were successfully incorporated in the solvent-borne formulation. Coatings were prepared with extremely low loadings of the nanoadditive (0.5 and 0.7 wt%). At these concentrations, the volume fraction of the nanofibrils in the coatings was calculated to be close to their percolation threshold. Two different pathways of CNF surface modification were applied to allow for a good compatibilization in the resin matrix, and the formulations were cured in two different settings. The effective compatibilization of the nanoadditive led to a significant variation of the viscoelastic properties in the coatings containing CNFs. The results from dynamic mechanical analysis (DMA) highlighted the effect of CNFs on the crosslinked network at the nanoscale, resulting in an increase in Tg. Additionally, an increase in the stress at break and Young's modulus was determined by tensile testing, while satisfactory elongation at break was preserved. Other relevant effects induced by the presence of CNFs on the properties of the coatings were highlighted, such as a significant matt effect, increased surface roughness and lower scratch resistance. A preliminary evaluation of the water barrier properties by electrochemical impedance spectroscopy (EIS) is also presented, suggesting that the incorporation of a hydrophilic nanoadditive did not lead to a deterioration of the coatings' performance. © 2023 The Authors

Place, publisher, year, edition, pages
Elsevier B.V., 2023
Keywords
Cellulose nanofibrils (CNFs), Coil coating, Compatibilizer, Mechanical reinforcement, Nanocomposite, Polyester–melamine, Cellulose, Coatings, Contact angle, Deterioration, Elastic moduli, Electrochemical impedance spectroscopy, Hydrophilicity, Nanofibers, Reinforcement, Solvents, Surface roughness, Tensile testing, Viscoelasticity, Cellulose nanofibril, Cellulose nanofibrils, Coating formulations, Coil coatings, Hydrophilics, Modified cellulose, Nanoadditives, Polyester-melamine, Surface-modified, Aspect ratio, Degradation, Water, Wettability
National Category
Paper, Pulp and Fiber Technology
Identifiers
urn:nbn:se:ri:diva-64632 (URN)10.1016/j.porgcoat.2023.107608 (DOI)2-s2.0-85152947285 (Scopus ID)
Note

 Funding details: Knut och Alice Wallenbergs Stiftelse; Funding details: Wallenberg Wood Science Center, WWSC; Funding text 1: This research was financially supported by SSAB Europe (Borlänge, Sweden), Wilhelm Beckers Jubileumsfond (Stockholm, Sweden) and the Knut and Alice Wallenberg Foundation (KAW) through the Wallenberg Wood Science Center (Stockholm, Sweden). 

Available from: 2023-05-15 Created: 2023-05-15 Last updated: 2023-05-15Bibliographically approved
Wärnheim, A., Edvinsson, C., Sundell, P.-E., Heydari, G., Deltin, T. & Persson, D. (2022). Depth-Resolved FTIR-ATR Imaging Studies of Coating Degradation during Accelerated and Natural Weathering─Influence of Biobased Reactive Diluents in Polyester Melamine Coil Coating. ACS Omega, 7(27), 23842
Open this publication in new window or tab >>Depth-Resolved FTIR-ATR Imaging Studies of Coating Degradation during Accelerated and Natural Weathering─Influence of Biobased Reactive Diluents in Polyester Melamine Coil Coating
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2022 (English)In: ACS Omega, E-ISSN 2470-1343, Vol. 7, no 27, p. 23842-Article in journal (Refereed) Published
Abstract [en]

Improved methods to assess the degradation of coil coatings to approximate lifetime have been an area of academic and industrial interest for decades. This work aims to elucidate the differences in the degradation behavior of two coil coating systems: one standard commercial formulation and one formulation with a significant addition of biorenewable reactive diluents. Depth-resolved degradation behavior of samples exposed to accelerated and natural field weathering is assessed. Focal plane array attenuated total reflection-Fourier transform infrared spectroscopy was used to acquire high-resolution chemical data from a sloping cross section. The results agreed with conventional photoacoustic spectroscopy. Degradation profiles for the two coatings were significantly different, with the biobased samples showing a more durable behavior. This study provides a method for detailed assessment of coating degradation, giving a good estimation of its durability. This is both a way to compare the performance of coating systems and to improve the understanding of the impact of exposure conditions, paving the way for the development of more sustainable coil coatings.

Keywords
FTIR focal plane array imaging, Coating degradation, Accelerated weathering, Field exposure, Biobased, Reactive diluent
National Category
Analytical Chemistry Polymer Technologies Materials Engineering Materials Chemistry
Identifiers
urn:nbn:se:ri:diva-59757 (URN)10.1021/acsomega.2c02523 (DOI)
Funder
Swedish Foundation for Strategic Research, FID18-0034
Note

This project is financially supported by the Swedish Foundation for Strategic Research (SSF).

Available from: 2022-07-01 Created: 2022-07-01 Last updated: 2023-07-06Bibliographically approved
Wärnheim, A. (2022). Practical utilization of AFM-IR: Chemical imaging on the nanoscale. In: : . Paper presented at Top Analytica, Microscopy and Microanalysis Workshop, Turku 2022.
Open this publication in new window or tab >>Practical utilization of AFM-IR: Chemical imaging on the nanoscale
2022 (English)Conference paper, Oral presentation only (Other academic)
National Category
Analytical Chemistry Materials Chemistry
Identifiers
urn:nbn:se:ri:diva-59759 (URN)
Conference
Top Analytica, Microscopy and Microanalysis Workshop, Turku 2022
Available from: 2022-07-01 Created: 2022-07-01 Last updated: 2023-05-09Bibliographically approved
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ORCID iD: ORCID iD iconorcid.org/0000-0001-6438-1357

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