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1
Content available remote Fungicidal activity of alkaloid from Colchicum species and its complexes
Kwaśniewska-Sip P., Cofta G., Kurek J.
Annals of Warsaw University of Life Sciences - SGGW. Forestry and Wood Technology
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2018
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No. 104
252--255
EN
The colchicine complexes with Na+ , K+ Mg2+ and Ca2+ cations of sulphates and carbonates have been synthesized and were tested against fungicidal activity. The obtained complexes were tested to determined minimal inhibitory concentration (MIC) and minimal fungicidal concentration (MFC) against microfungi using 96-well microtiter plate-based method. The colchicine itself wasn’t active against most of used microfungi with the exception of A. pullulans. Colchicine complexes with K2CO3 and MgSO4 inhibited growth the majority of tested microfungi.
2
Content available remote Flammability of wood treated with caffeine
Cofta G., Grześkowiak W., Kwaśniewska-Sip P.
Annals of Warsaw University of Life Sciences - SGGW. Forestry and Wood Technology
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2018
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No. 104
106--108
EN
The aim of the study was to determine the effect on the flammability of wood (beech, poplar and pine) impregnated with 1% and 2% caffeine an aqueous solution. The test was carried out with the modified ASTM E 69 method. It was found that a 1% caffeine solution slightly increases the mass loss when burning pine, beech and poplar wood. The exception is the 2% caffeine solution, which caused a decrease in the temperature and mass loss of beech wood.
3
Content available remote Caffeine as anti-mould additive for wood preservative contain copper
Cofta G., Kwaśniewska-Sip P., Weltrowski K.
Annals of Warsaw University of Life Sciences - SGGW. Forestry and Wood Technology
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2018
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No. 104
101--105
EN
The aim of the work was the assessment of caffeine as an anti-mold additive in a commercial wood preservative containing copper for pressure impregnation. The wood preservative was enriched with caffeine of five different concentrations (1%, 0.5%, 0.25%, 0.125% and 0.0625%). Four microfungi A. niger, P. funiculosum, P. variotii and T. viride were used in the mycological test. It was found that the mixture of wood preservative and 1% caffeine protects until the 7th day to an extent satisfactory for wood against mold growth.
4
Content available remote A. niger susceptibility of HDPE/hemp composites. Part 2: Mechanical tests
Cofta G., Doczekalska B., Bujnowicz K., Roszyk E.
Annals of Warsaw University of Life Sciences - SGGW. Forestry and Wood Technology
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2018
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No. 104
113--116
EN
In the present study the composites of polyethylene and hemp were prepared. In addition the polyethylene-hemp composites containing a Polybond 3039 were also obtained. The objective of this study was to evaluate the resistance of PE-hemp composites to fungal decay. Mechanical properties of composite samples before and after the mycological test were determined. It was shown that the addition of coupling agent was accompanied by an increase of the measured mechanical composites properties. A. niger did not change the mechanical parameters of the composites. Mycological tests practically no effect on any of the mechanical parameters of both variants of the stretched composite samples.
5
Content available remote A. niger susceptibility of HDPE/hemp composites. Part 1: Resistance to growth of A. niger on the surface
Cofta G., Doczekalska B., Bujnowicz K.
Annals of Warsaw University of Life Sciences - SGGW. Forestry and Wood Technology
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2018
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No. 104
109--112
EN
In the present study the composites of polyethylene and hemp were prepared. In addition the polyethylene-hemp composites containing a Polybond 3039 were also obtained. The objective of this study was to evaluate the resistance of PE-hemp composites to attack by mold. At weekly intervals, composites was evaluated visually intensity of the growth of A. niger using the scale on a surface in accordance with ISO-846. It was found that A. niger grew the surface of composites within two weeks. The use of the Polybond 3039 (coupling agent) reduces the resistance of composites to A. niger. Fungus grew faster on the surface of the PE70 H30 P5 composite samples than the composite designated as PE65 H30.
6
Content available remote Resistance of polypropylene-wood composites to fungi
Cofta G., Borysiak S., Doczekalska B., Garbarczyk J.
Polimery
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2006
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T. 51, nr 4
276-279
EN
In the present study, the composites of polypropylene and wood were prepared. The experimental material comprised two most common Polish timber species pine wood (Pinus sylvestris L.) as a softwood species and oak wood (Quercus sp.) as a hardwood species. The size of wood sawdust ranged from 0.5 to 1.0 mm. Two types of lignocellulosic materials were used in the experiments described: wood without any previous chemical treatment and wood after its mercerization (i.e. activated with NaOH). In addition the polypropylene-wood composite containing a block copolymer, i.e. styrene-ethylene-butylene-styrene (SEBS) was also obtained. The objective of this study was to evaluate the resistance of different kinds of polypropylene-wood composites to fungal decay. Weight losses and temporary tensile strength of composite samples after the mycological test were determined.
PL
Metodą wytłaczania i prasowania wytworzono kompozyty izotaktyczne polipropylen-drewno. W badaniach wykorzystano dwa gatunki drewna: sosnowe (Pinus sylvestris L.) i dębowe (Quercus sp.). W pracy stosowano drewno surowe oraz drewno po procesie merceryzacji, tj. po aktywowaniu wodnym roztworem NaOH. Wytworzono również kompozyty polipropylen-drewno z dodatkiem kopolimeru blokowego styren-etylen-butylen-styren (SEBS). Badano odporność uzyskanych kompozytów na rozkład powodowany przez grzyby degradujące tkankę drzewną (Coniophora puteana i Coriolus versicolor). W celu oceny stopnia biorozkładu po upływie 16 tygodni wyznaczano ubytki masy próbek kompozytów oraz badano ich wytrzymałość na rozciąganie. Stwierdzono, że ubytki masy (rys. 1) wszystkich wariantów kompozytów wynosiły poniżej 1,8 %. Uzyskane wartości mieszczą się w granicach błędu pomiaru. Stwierdzono, że wytrzymałość na rozciąganie (rys. 2) jest bardziej dokładnym kryterium biorozkładu. Obniżenie wytrzymałości na rozciąganie od 12 do 20 % stwierdzono w przypadku kompozytów na bazie drewna sosnowego, a niewielkie zmiany (do 5 %) w przypadku kompozytów z drewna dębowego. Natomiast najmniejszą wytrzymałość na zerwanie wykazywały kompozyty z dodatkiem środka kompatibilizującego (SEBS). Badania dowiodły, że możliwa jest biodegradacja drewna w matrycy polipropylenowej, pod warunkiem zapewniania dostępu strzępek grzybni do materiału lignocelulozowego w kompozycie.
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