The effect of ageing on bonding performance of plasma treated beech wood with urea-formaldehyde adhesive

Žigon, Jure (author), Saražin, Jaša (author), Šernek, Milan (author), Kovač, Janez (author), Dahle, Sebastian (author)

In the process of wood bonding, the usage of aged and inactivated wooden elements can cause a reduction in mechanical properties of products containing wood-adhesive joints. Treating wood with an atmospheric air plasma represents a sophisticated technique for surface activation. With this regard, to enhance the bondability of normal beech wood (Fagus sylvatica L.) with urea-formaldehyde (UF) adhesive, a dielectric barrier discharge plasma in floating electrode configuration was implemented. In this study, fresh and aged wood specimen both, untreated and plasma treated, were investigated. X-ray photoelectron spectroscopy revealed promotion of carbon-rich species with ageing, but generation of a new functional oxygen-containing functional groups after plasma treatment. Microscopic observations with scanning electron microscope showed no obvious changes in the wood structure after plasma treatment. Surface oxidation consequently improved the wettability of the wood surface with water and UF adhesive. However, this enhanced wettability slightly diminished over time. As shown with dynamic mechanical analysis, the rheological properties of the UF adhesive in wood-adhesive joints were not affected by aging nor by plasma treatment. The positive influence of plasma treatment and negative impact of substrate ageing to the shear strengths of wood lap-joints were determined using an automated bonding evaluation system. Similarly, the negative effect of wood ageing and the positive effect of plasma pre-treatment were reflected in the bending strengths of the produced laminated veneer lumbers. Results showed that plasma treatment of beech wood improves the bonding performance of both fresh and aged wood.

• Language: English
• Keywords: ageing, bonding, wood, plasma, urea-formaldehyde adhesive, surface
• Work type: Article
• Typology: 1.01 - Original Scientific Article
• Organization: BF - Biotechnical Faculty
• Publication status: Published
• Publication version: Version of Record
• Publication date: 01.01.2021
• Year: 2021
• Number of pages: Str. 2461-2478
• Numbering: Vol. 28, iss. 4
• PID: 20.500.12556/RUL-138724
• UDC: 630*8
• ISSN on article: 1572-882X
• DOI: 10.1007/s10570-021-03687-z
• COBISS.SI-ID: 49872899
• Publication date in RUL: 10.08.2022

Record is a part of a journal

• Title: Cellulose
• Shortened title: Cellulose
• Publisher: Springer Nature
• ISSN: 1572-882X
• COBISS.SI-ID: 513134105

Licences

• License: CC BY 4.0, Creative Commons Attribution 4.0 International
• Link: http://creativecommons.org/licenses/by/4.0/
• Description: This is the standard Creative Commons license that gives others maximum freedom to do what they want with the work as long as they credit the author.

Secondary language

• Language: Slovenian
• Keywords: staranje, lepljenje, les, plazma, urea-formaldehidno lepilo, površina

Projects

• Funder: ARRS - Slovenian Research Agency
• Project number: P4-0015
• Name: Les in lignocelulozni kompoziti

• Funder: ARRS - Slovenian Research Agency
• Project number: P2-0082
• Name: Tankoplastne strukture in plazemsko inženirstvo površin