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1
Content available remote Oak wood pre-treated by cold plasma
Novák I., Kleinová A., Sedliačik J., Matyašovský J., Jurkovič P.
Annals of Warsaw University of Life Sciences - SGGW. Forestry and Wood Technology
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2018
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No. 104
163--168
EN
The cold plasma was used to improve the hydrophilicity of oak wood. A significant increase of the polar component of oak wood surface energy after modification by cold discharge plasma has been observed. The polar component of the surface energy is associated with the presence of acid-base forces (electron donor-acceptor bonds). FTIR spectra confirm the changes in C=O and C–O–C bonds that occur on the cold plasma modified wood. The integrated intensities ratios of oxygen function absorption with the majority of polar –OH groups contribution with a maximum at 3400 cm-1 and a maximum of non-polar CH2-groups with a maximum at 2985 cm-1 (–CH2 groups)sym shows an increase of the ratio P(OH)/P(– CH2) during plasma treatment of the oak wood.
2
Content available remote Metallocene polyolefins for hot melt adhesives preparation
Novák I., Pavlinec J., Chodák I., Preťo J., Vanko V.
Annals of Warsaw University of Life Sciences - SGGW. Forestry and Wood Technology
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2018
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No. 104
154--157
EN
Efficient method of metallocene polyolefin grafting in solution was used to initiate the creation of peroxides and hydroperoxides molecules accumulated on polyolefin after activation controlled by thermal oxidation. Efficacy of grafting of RXP in toluene was relatively low and reached the value 0.24 - 0.49.
3
Content available remote FTIR of grafted metallocene polyolefins for hot melt adhesives
Novák I., Pavlinec J., Chodák I., Kleinová A., Preťo J., Vanko V.
Annals of Warsaw University of Life Sciences - SGGW. Forestry and Wood Technology
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2018
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No. 104
157--162
EN
The activated RXP suspended in an aqueous acrylic acid (AA) solution does contain peroxide groups in sufficient concentration. The temperature of 60°C is too low to generate free radicals to initiate grafting. FTIR absorbance for acid carbonyl compounds at 1715 cm-1 and at 1464 cm-1 show the proliferation of PAA graft quantity depending on the amount of AA in the feedstock.
4
Content available remote Discharge plasma treatment of wood surfaces
Novák I., Kleinová A., Sedliačik J., Matyašovský J., Jurkovič P.
Annals of Warsaw University of Life Sciences - SGGW. Forestry and Wood Technology
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2018
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No. 104
169--173
EN
The water contact angle of various wood species treated by radio-frequency discharge (RFD) plasma in air decreased with activation time from 75 up to 40 deg. The growth of water contact angle of plasma-treated wood from 37 up to 68 deg during aging was faster within 2 days after the plasma pre-treatment. The water contact angles of tested wood species showed a steep decrease after activation by RFD plasma in air. Water contact angles were markedly increased during the first 2 days of aging. RFD plasma-treated wood surfaces should be treated up to 2 days after modification by plasma. The unmodified beech wood sample shows lower roughness compared to wood surface treated by RF-plasma. Higher roughness of the plasma-treated wood samples is related to the ablation of amorphous lignin on the surface of the beech wood.
5
Content available Acrylic Acid Plasma Treatment of Polypropylene Nonwoven Fabric
Buček A., Popelka A., Zahoranová A., Kováčik D., Novák I., Černák M.
Fibres & Textiles in Eastern Europe
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2016
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Vol. 24, no. 6 (120)
161--164
EN
Nowadays hydrogel materials are being used in medical practice for wound dressing purposes. Hydrogel/textile composites can be formed to increase the mechanical strength and handling capability of hydrogel materials. Nonwoven textiles are optional for such applications, however, it is often necessary to improve their surface properties. Here plasma activation/grafting of polypropylene (PP) nonwoven fabric with an acrylate layer to improve its adhesive properties is reported. A diaphragm discharge was used for the plasma treatment of the PP fabric. The discharge was burnt in a solution of acrylic acid (AAc), which resulted in a single step process of plasma activation and plasma grafting of the fabric. Results of wettability testing and ATR-FTIR measurements showed the existence of a thin poly(acrylic acid) (PAAc) layer grafted on the fabric surface. Peel strength measurements showed a 4.7 fold increase in the peel strength when compared with untreated PP fabric.
PL
Współcześnie materiały hydrożelowe używane są w wyrobach medycznych jako opatrunki na rany. Hydrożelowe kompozyty tekstylne formuje się dla zwiększenia mechanicznej wytrzymałości poręczności w stosowaniu. Włókniny są powszechnie stosowane do wyrobów medycznych, jednak jest konieczne polepszenie ich właściwości powierzchniowych. W badaniach zastosowano aktywację plazmową w celu pokrycia włóknin polipropylenowych warstwą akrylową dla polepszenia właściwości adhezyjnych. Wyładowania odbywały się w roztworze kwasu akrylowego co pozwoliło na przeprowadzenie jednostopniowego procesu aktywacji plazmowej. Wyniki pomiarów zwilżalności oraz badania ATR-FTIR wykazały istnienie cienkiej warstwy kwasu poliakrylowego na powierzchni włókniny. Stwierdzono 4.7 razy większą wytrzymałość na odrywanie w stosunku do włóknin niemodyfikowanych.
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