Projects / Programmes source: ARRS

Premazi iz utekočinjenega lesa (Slovene)

Research activity

Code Science Field Subfield
4.01.02  Biotechnical sciences  Forestry, wood and paper technology  Wood technology 

Code Science Field
2.05  Engineering and Technology  Materials engineering 
Evaluation (rules)
source: COBISS
Researchers (15)
no. Code Name and surname Research area Role Period No. of publications
1.  28502  PhD Franc Budija  Forestry, wood and paper technology  Junior researcher  2009 - 2010  37 
2.  03439  PhD Peter Bukovec  Chemistry  Researcher  2009 - 2012  543 
3.  16256  PhD Romana Cerc Korošec  Chemistry  Researcher  2009  318 
4.  29824  PhD Samo Fišinger  Physics  Researcher  2009 
5.  20691  PhD Petra Grošelj  Interdisciplinary research  Researcher  2010  150 
6.  19106  PhD Miha Humar  Forestry, wood and paper technology  Researcher  2009 - 2012  1,208 
7.  29227  PhD Mirko Kariž  Forestry, wood and paper technology  Researcher  2009 - 2012  151 
8.  30737  Matija Kranjc  Forestry, wood and paper technology  Junior researcher  2009 - 2011 
9.  17846  Borut Kričej    Technician  2009 - 2012  434 
10.  13400  PhD Leon Oblak  Forestry, wood and paper technology  Researcher  2009 - 2012  448 
11.  20386  PhD Matjaž Pavlič  Forestry, wood and paper technology  Researcher  2009 - 2012  485 
12.  00395  PhD Marko Petrič  Forestry, wood and paper technology  Principal Researcher  2009 - 2012  871 
13.  05248  PhD Franc Pohleven  Forestry, wood and paper technology  Researcher  2009 - 2012  1,191 
14.  16382  PhD Milan Šernek  Forestry, wood and paper technology  Researcher  2009 - 2012  551 
15.  19719  PhD Črtomir Tavzes  Forestry, wood and paper technology  Researcher  2010 - 2012  184 
Organisations (2)
no. Code Research organisation City Registration number No. of publications
1.  0103  University of Ljubljana, Faculty of Chemistry and Chemical Technology  Ljubljana  1626990  21,902 
2.  0481  University of Ljubljana, Biotechnical Faculty  Ljubljana  1626914  64,542 
Significance for science
Realisation of the project programme partially elucidated liquefaction reactions of selected lignocellulosics, however they still remain quite unclear. In the volatile liquefaction products, the presence of levulinic acid, furfural and dioxane was identified. There has been even less knowledge on the crosslinking of liquefied wood with different reagents, and especially of self-crosslinking of liquefied lignocellulosic materials. OH group contribution from diethylene glycol (DEG) in the liquid mixture of liquefied wood and DEG was found to be even 40 %. We found out that the exposure of the excess solvent free reaction product (ESFLW) for 24 hours at 130 ° C resulted in its self-crosslinking. Thusly created biopolymer network is probably of a polyether and/or ester type. The discovered self-crosslinking ability of ESFLW is an important novelty, because this product can be prepared independently for biopolymer adhesives or coatings. According to literature data, liquefied wood has been up to now used only as one component in preparation of multicomponent systems (polyurethanes, polyepoxides, polyesters). It was also found out that the partially crosslinked liquefied poplar wood, prepared in glycerol, when the excessive solvent was not removed, probably consists of a network of polyether ketones with a certain share of aromatic compounds. An interesting finding was also the possibility of the use of the glycerol and a sulphuric acid reaction product for surface treatment. The composition of liquefied matter and the processes of crosslinking and self-crosslinking were investigated by some selected physical and chemical methods that have been utilised in the biorefineries field for the first time, and thus contributed also to the field of instrumental methodology. Research of liquefaction possibilities of wood that had been treated with inorganic preservatives (CCB) (polluted/previously impregnated waste wood) represents an original contribution to wood science and technology, as well. From wood, impregnated with boron based protective formulations, less boron leached out than from wood, protected with commercial boron based preservatives. The problem of boron leaching is an important challenge in the field of wood protection and our results represent a contribution do mitigate this problem. Tests of leachability of Cu from spruce wood, impregnated with CCB containing spruce wood also brought some promising results. On the other hand, it seems that the liquefied wood, containing remaining of biocides, could not be applied as a wood preservative, due to its too low protective efficacy. Possibilities of application of liquefied wood in wood adhesives have been investigated as well. Influence of pH of liquefied on shear strength of adhesive bonds was also elucidated. Shear strength of liquefied wood based adhesive bonds did not decrease during exposure to standard climatic conditions, what represent the progress – contribution to new findings in the field of liquefied wood based adhesives. An important drawback of liquefied wood based coatings is their dark colour. Experiments within the frame of the L4-2144 project gave promising results also in this area – light coloured coatings from liquefied wood were prepared. According to our best knowledge, this finding is also a novelty in investigations of liquefied wood and its applications. The investigations contributed to international scientific collaboration in the frame of bilateral projects (Proteus – with France, Slovenian – Finnish project) and in the frame of COST FP1006, strengthening the common research area in the field of biomass liquefaction and applications of liquefied lignocellulosics.
Significance for the country
Biomass liquefaction was performed by using diethylene glycol (DEG), ethylene glycol, polyethylene glycol and also glycerol. Glycerol is a by-product of biodiesel production. Increase of glycerol usage in liquefaction processes would result in production of high value added products from an industrial residue. Pollution with oil refinery derivatives would be deceased as well. Potential applications of up to now poorly exploited or even unexploited wooden residues and/or waste could contribute to sustainable development of Slovenia and to mitigation of global climate changes. Production of new materials from biomass could be performed at primary wood processing plants and in other industries that produce large amounts of wood residues and/or wastes. The mentioned plants are located predominantly in rural regions, so application of the project’s results could contribute to balanced regional development of the country. Our additional finding is that glycerol itself, without wood, could be used for preparation of crosslinked polymers, including wood coatings, after the reaction with a sulphuric acid. So, completely new possibilities of use of natural renewable resources are open. On the other hand, if DEG is used for solvolysis and it is evaporated from the mixture prior to selfcrosslinking, it could be recycled, which has positive economic impacts. It was shown that unreacted excessive DEG contributes to at least 40 % of all available hydroxyl groups in the product, obtained by liquefaction of wood with DEG. Use of liquefied wood without unreacted DEG could therefore significantly lower the consumption of other components in preparation of two component systems or syntheses of crosslinked polymers. The presence of levulinic acid in DEG distillate was confirmed. Levulinic acid can be used for syntheses of various chemicals and it is therefore an excellent raw material which is derived from a renewable resource - wood. The volatile products formed contained, among other compounds, furfural, dioxane and DEG. Furfural can be used for further syntheses of new compounds. From the glycerol liquefied poplar wood as well from the product of the reaction between glycerol and sulphuric acid, without wood, we prepared various surface finishing systems and tested their resistance against artificial accelerated weathering. It came out, that the prepared coatings could be currently used in interior. The experiments showed possibility of wood adhesive production, as well. New coatings and adhesives on the basis of renewable resources could contribute to a wider production assortment and could increase the companies’ competitiveness. Wood, previously treated/preserved and now contaminated with inorganic pollutants (CCB), represents a special environmental and economic challenge, since its storage in special landfills is expensive, and combustion in special incinerators with electric filtering of the pollutants makes almost no sense in terms of energy balance. One of the goals of the proposed project is liquefaction of such wood with subsequent inactivation of the pollutants by the incorporation into newly produced polymeric material, or their removal from the liquefied matter. Our preliminary results are promising, so they could contribute to an environment-friendly management of recovered preservative-contaminated wood. One year investigation results have shown that apart from wood, liquefaction of other biomass types are possible, for example of the so called celulignin that is a residue formed during tannin production. This is the way to spread possibilities of application of almost worthless residues for high value added products.
Most important scientific results Annual report 2009, 2010, 2011, final report, complete report on dLib.si
Most important socioeconomically and culturally relevant results Annual report 2009, 2010, 2011, final report, complete report on dLib.si
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