1
|
Bernaczyk A, Wagenführ A, Zboray R, Flisch A, Lüthi T, Vetter B, Rentsch M, Terfloth C, Lincke J, Krystofiak T, Niemz P. Investigations on the Characterization of Various Adhesive Joints by Means of Nanoindentation and Computer Tomography. MATERIALS (BASEL, SWITZERLAND) 2022; 15:8604. [PMID: 36500102 PMCID: PMC9739271 DOI: 10.3390/ma15238604] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/26/2022] [Revised: 11/21/2022] [Accepted: 11/24/2022] [Indexed: 06/17/2023]
Abstract
The mechanical properties of cured wood adhesive films were tested in a dry state by means of nanoindentation. These studies have found that the application of adhesives have an effect on the accuracy of the hardness and elastic modulus determination. The highest values of hardness among the tested adhesives at 20 °C have condensation resins: MF (0.64 GPa) and RPF (0.52 GPa). Then the decreasing EPI (0.43 GPa), PUR (0.23 GPa) and PVAc (0.14 GPa) adhesives. The values of the elastic modulus look a little bit different. The highest values among the tested adhesives at 20 °C have EPI (11.97 GPa), followed by MF (10.54 GPa), RPF (7.98 GPa), PVAc (4.71 GPa) and PUR (3.37 GPa). X-ray micro-computed tomography was used to evaluate the adhesive joint by the determination of the voids. It has been proven that this value depends on the type of adhesive, glue quantity and reactivity. The highest values of the void ratio achieve the PUR (17.26%) adhesives, then PVAc (13.97%), RRF (6.88%), MF (1.78%) and EPI (0.03%). The ratio of the gaps increases with the higher joint thickness. A too high proportion of voids may weaken the adhesive joint.
Collapse
Affiliation(s)
| | - André Wagenführ
- Institute of Natural Materials Technology, Technische Universität Dresden, 01062 Dresden, Germany
| | - Robert Zboray
- Center for X-ray Analytics, Empa—Swiss Federal Laboratories for Materials Science and Technology, 8600 Dübendorf, Switzerland
| | - Alexander Flisch
- Center for X-ray Analytics, Empa—Swiss Federal Laboratories for Materials Science and Technology, 8600 Dübendorf, Switzerland
| | - Thomas Lüthi
- Center for X-ray Analytics, Empa—Swiss Federal Laboratories for Materials Science and Technology, 8600 Dübendorf, Switzerland
| | - Birgit Vetter
- Institute of Materials Science, Technische Universität Dresden, 01062 Dresden, Germany
| | - Mario Rentsch
- Institute of Materials Science, Technische Universität Dresden, 01062 Dresden, Germany
| | | | | | - Tomasz Krystofiak
- Department of Wood Science and Thermal Techniques, Poznań University of Life Sciences, 60-627 Poznan, Poland
| | - Peter Niemz
- Lulea University of Technology, 971 87 Lulea, Sweden
| |
Collapse
|
2
|
Mamoňová M, Ciglian D, Reinprecht L. SEM Analysis of Glued Joints of Thermally Modified Wood Bonded with PUR and PVAc Glues. MATERIALS (BASEL, SWITZERLAND) 2022; 15:6440. [PMID: 36143752 PMCID: PMC9503839 DOI: 10.3390/ma15186440] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 07/21/2022] [Revised: 09/07/2022] [Accepted: 09/13/2022] [Indexed: 06/16/2023]
Abstract
This study deals with the scanning electron microscopy (SEM) analyses of the phase interfaces in the glued joints between Norway spruce wood elements thermally modified at 160, 180, 200, and 220 °C/4 h and polyurethane (PUR) and polyvinyl acetate (PVAc) glues with the aim of evaluating various anatomical influences of wood on the quality of joints. Due to cracked regions created in the surface of spruce wood at severe thermal modifications, the penetration depth of glues doubled from 140 to 241 μm for PUR glue, and from 100 to 200 μm for PVAc glue. The thickness of glue lines in joints was apparently higher for PVAc glue, mainly in earlywood regions; however, in joints from thermally modified (TM) woods it increased more apparently for PUR glue from 16.6 to 44.4 μm, probably in connection with formation of micro-bubbles in its structure. The SEM analyses corresponded well with the previous knowledge about lower shear strength of glued joints formed from the more intensively TM spruce elements and mentioned types of glues.
Collapse
Affiliation(s)
- Miroslava Mamoňová
- Department of Wood Science, Faculty of Wood Sciences and Technology, Technical University in Zvolen, T. G. Masaryka 24, 960 01 Zvolen, Slovakia
| | - Dávid Ciglian
- Department of Wood Technology, Faculty of Wood Sciences and Technology, Technical University in Zvolen, T. G. Masaryka 24, 960 01 Zvolen, Slovakia
| | - Ladislav Reinprecht
- Department of Wood Technology, Faculty of Wood Sciences and Technology, Technical University in Zvolen, T. G. Masaryka 24, 960 01 Zvolen, Slovakia
| |
Collapse
|
3
|
The Impact of a CO2 Laser on the Adhesion and Mold Resistance of a Synthetic Polymer Layer on a Wood Surface. FORESTS 2021. [DOI: 10.3390/f12020242] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
In the wood industry, laser technologies are commonly applied for the sawing, engraving, or perforation of solid wood and wood composites, but less knowledge exists about their effect on the joining and painting of wood materials with synthetic polymer adhesives and coatings. In this work, a CO2 laser with irradiation doses from 2.1 to 18.8 J·cm−2 was used for the modification of European beech (Fagus sylvatica L.) and Norway spruce (Picea abies /L./ Karst) wood surfaces—either in the native state or after covering them with a layer of polyvinyl acetate (PVAc) or polyurethane (PUR) polymer. The adhesion strength of the phase interface “synthetic polymer—wood”, evaluated by the standard EN ISO 4624, decreased significantly and proportionately in all the laser modification modes, with higher irradiation doses leading to a more apparent degradation and carbonization of the wood adherent or the synthetic polymer layer. The mold resistance of the polymers, evaluated by the standard EN 15457, increased significantly for the less mold-resistant PVAc polymer after its irradiation on the wood adherent. However, the more mold-resistant PUR polymer was able to better resist the microscopic fungi Aspergillus niger Tiegh. and Penicillium purpurogenum Stoll. when irradiation doses of higher intensity acted firstly on the wood adherent.
Collapse
|
4
|
KÖKEN N, Aydın S. Synthesis of Reactive Polyurethane Adhesives and Studying the Effect of Ketonic Resins. JOURNAL OF THE TURKISH CHEMICAL SOCIETY, SECTION A: CHEMISTRY 2019. [DOI: 10.18596/jotcsa.495458] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022] Open
|
5
|
Sahoo S, Mohanty S, Nayak SK. Biobased polyurethane adhesive over petroleum based adhesive: Use of renewable resource. JOURNAL OF MACROMOLECULAR SCIENCE PART A-PURE AND APPLIED CHEMISTRY 2017. [DOI: 10.1080/10601325.2017.1387486] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Affiliation(s)
- Swarnalata Sahoo
- Central Institute of Plastic Engineering and Technology (CIPET), Chennai, Tamilnadu
- Laboratory for advanced research in polymeric materials, LARPM, CIPET, Bhubaneswar, Odisha
| | - Smita Mohanty
- Central Institute of Plastic Engineering and Technology (CIPET), Chennai, Tamilnadu
- Laboratory for advanced research in polymeric materials, LARPM, CIPET, Bhubaneswar, Odisha
| | - Sanjay Kumar Nayak
- Central Institute of Plastic Engineering and Technology (CIPET), Chennai, Tamilnadu
- Laboratory for advanced research in polymeric materials, LARPM, CIPET, Bhubaneswar, Odisha
| |
Collapse
|
6
|
Clauß S, Dijkstra DJ, Gabriel J, Karbach A, Matner M, Meckel W, Niemz P. Influence of the filler material on the thermal stability of one-component moisture-curing polyurethane adhesives. J Appl Polym Sci 2011. [DOI: 10.1002/app.35223] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
|