Penetration of urea-formaldehyde adhesives of different molar mass into some domestic wood species tissue. [Doctoral dissertation] | Penetracija urea-formaldehidnih adheziva različitih molarnih masa u tkivo nekih domaćih vrsta drveta. Doktorska disertacija
2010
Gavrilović-Grmuša, I.
Adhesive penetration plays an important role in wood adhesion and seems to be basic requirement for quality adhesive bonding. Objective of this work was the evaluation of distribution and penetration of urea-formaldehyde (UF) adhesive emulsion into the beech, fir and poplar wood tissue, by means of different microscopic methods of detection. It was followed by investigation of strength of adhesive bonding. Epi-fluorescence Microscopy, Fluorescence Confocal Laser Scanning Microscopy (CLSM), Scanning Electron Microscopy (SEM) and Atomic Force Microscopy (AFM) were used as the main methods for measuring of adhesive penetration and distribution. The results showed a significant correlation between the penetration behavior and the molar mass of the adhesives. The higher the molar mass, the lower the possibility for radial and tangential penetration, expressed as average penetration (AP) for all investigated wood species. AP was the highest in poplar and the lowest in fir tissue. Tangential AP was higher then radial AP in all cases. Portion of filled tracheides and vessels on the whole cross section of interphase (filled interphase region-FIR) increased with the raise of molar mass for all wood species. The equal quality adhesive bonding could achieve by smaller loading level in hardwood than in softwood.
显示更多 [+] 显示较少 [-]