20.500.12556/RUL-172998 Analiza lepilnega spoja v bukovem lesu Analysis of adhesive joint using beech wood Les je porozen in anizotropen material z raznoliko naravno anatomijo. Pri iglavcih so glavni strukturni elementi vzdolžne traheide, medtem ko pri listavcih, kot je bukev, to vključuje žilne elemente in vzdolžna vlakna. Lumen teh celic je običajno dovolj velik, da omogoča penetracijo tekočega lepila, kar je bistvenega pomena za oblikovanje močnih in trajnih spojev. Kljub temu so lepilni spoji pogosto obravnavani kot najšibkejši del sestavljenih lesenih konstrukcij, saj imajo ključno vlogo pri prenosu obremenitev preko lepilnega vmesnika. To poudarja potrebo po poglobljenem razumevanju učinkovitosti in obnašanja lepil v lesnih sistemih. V tej študiji je bil uporabljen bukov les z dvema različnima orientacijama rastnih vlaken/letnic (radialno in tangencialno). Vzorci so bili lepljeni z dvema vrstama lepil: poliuretanskim lepilom (PUR) in ribjim klejem (RK). Vsi vzorci so bili pripravljeni v skladu s standardom EN 302-1 in izpostavljeni naravnemu staranju tri mesece na prostem v Lizboni. Preiskava je bila osredotočena na oceno globine in razporeditve penetracije lepila v plošče z različnimi kombinacijami orientacije letnic. Poleg tega so bili analizirani vplivi dolžine izpostavljenosti zunanjim pogojem na mehanske, fizikalne in kemijske spremembe lesa, lepila in lepilnih spojev. Ker vzorcev, lepljenih z RK, zaradi visoke topnosti v vodi nismo mogli analizirati, ta raziskava temelji na študiji sistema bukev-PUR-bukev. Pri raziskavi je bil uporabljen širok nabor analitskih tehnik, vključno s testom strižne trdnosti, vrstično elektronsko mikroskopijo (SEM), sklopljeno z energijsko disperzijsko spektroskopijo (EDS), rentgensko difrakcijo (XRD), epi-fluorescenčno mikroskopijo, Fourierjevo transformacijsko infrardečo spektroskopijo (FTIR, μFTIR), ramansko spektroskopijo in mikroračunalniško tomografijo (μCT). Študija je prav tako ovrednotila natančnost in zanesljivost teh metod pri karakterizaciji obravnavanih sistemov. Wood is a porous, anisotropic material characterized by a variety of natural anatomical features. In softwoods, the main structural components are longitudinal tracheids, while in hardwoods, these consist of vessel elements and longitudinal fibers. The lumens of these cells are typically large enough to allow the infiltration of liquid adhesives, which is essential for achieving strong and durable bonds. However, adhesive joints are often considered the weakest links in assembled wooden structures, as they are critical for transferring loads across the bonding interface. This highlights the importance of studying adhesive performance and behavior in such systems. This study utilized beech wood with two different grain orientations (radial and tangential) and bonded the specimens using two types of adhesives: polyurethane (PUR) and fish glue (RK). The samples were prepared following the EN 302-1 standard and subjected to natural weathering for three months in Lisbon, Portugal. Due to the high solubility in water, we were unable to analyze the samples glued with RK, so this research is based on a study of the beech wood-PUR-beech wood system. The investigation focused on assessing both the depth and distribution of adhesive penetration in to plates with various combinations of fiber/growth rings orientations. Additionally, the impact of aging was analyzed by observing mechanical, physical, and chemical changes in the bonded joints over time. A wide range of analytical techniques was applied, including tensile-shear testing, Scanning Electron Microscopy (SEM) coupled with Energy Dispersive Spectroscopy (EDS), X-ray Diffraction (XRD), epi-fluorescence microscopy, Fourier-transform infrared spectroscopy (FTIR, μFTIR), Raman microscopy, and micro-computed tomography (μCT). The study also evaluated the precision and reliability of these methods in characterizing the bonded interfaces. bukovina poliuretansko lepilo lepilni spoj penetracija staranje beech wood polyurethane adhesive adhesive joint penetration aging true false false Slovenski jezik Angleški jezik Magistrsko delo/naloga 2025-09-12 08:40:00 2025-09-12 08:40:04 2025-11-13 15:07:39 0000-00-00 00:00:00 2025 0 0 0000-00-00 NiDoloceno NiDoloceno NiDoloceno 0000-00-00 0000-00-00 0000-00-00 25323 257132035 Likeb_Tjasa_-_Analiza_lepilnega_spoja_v_bukovem_lesu.pdf Likeb_Tjasa_-_Analiza_lepilnega_spoja_v_bukovem_lesu.pdf 1 79DBBA56D5986B1981F8D4D882DB038A 46afd51172e6f0aa624da90f33265823d65fa925daa52e22202f9aeaee18514f 2718a927-8fa3-11f0-9328-0050569b8976 https://repozitorij.uni-lj.si/Dokument.php?lang=slv&id=217150 Fakulteta za kemijo in kemijsko tehnologijo 0 0 0