Annals of Warsaw University of Life Sciences - SGGW

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We can say that HC included in adhesive mixture markedly reduced formaldehyde content in glued material. While the board glued with UF adhesive with hardener Hr1 showed the reduction of formaldehyde by 9 %, HC added into the adhesive caused the lowering of formaldehyde content by 15 %. As for the adhesive mixture with Hr3, the mentioned values were 5 % and 26 %. The interesting is the fact that lower AG content results in stronger decrease of formaldehyde in the adhesive mixture without protein (without HC). In adhesive mixture with protein, it is better if the AG content is higher. We can see this tendency only when compare Hr1 to Hr3. The sample glued with adhesive with HC and Hr5 showed higher formaldehyde content. Based on our experiments examining also other properties of adhesive joints, we continued the experiments with UF adhesive and Hr3. We measured formaldehyde emission from boards glued with the adhesive containing HC in the amount 3 %, 5 %, or 8 % (fig. 1). fd emission (%) 100 90 80 70 60 50 40 30 20 10 0 UF-R UF+3%HC UF+5%HC UF+8%HC Adhesive mixture Fig. 1 Emission of formaldehyde dependent on the amount of added HC As we can see, addition of HC in researched range (3–8 %) results in reduction of formaldehyde emissions when compared with reference sample (R with no additive). The adhesive mixture with highest content of HC (8 %) reached the lowest value of formaldehyde emission. All boards met the standard, they reached the emission value E < 0.124 mg/m 3 and all of them can be classified in emission class E1. We assume that between the adhesive and the chains of natural polymer (HC present in the adhesive mixture) direct chemical bond is formed; that can be manifested by changed properties of cured adhesive. ESSAWY et al. (2009) researched physical-chemical properties of UF adhesives modified with polyamidoamines. Authors expected modifiers to change the network structure of cured adhesive (due to a high number of –NH 2 functional groups). The adhesives showed higher strength and chemical stability, as well. Protein added in the form of hydroysate can immediately influence the content of free formaldehyde in the adhesive. Free amino-groups of protein are able to react with free formaldehyde molecules, they bond them, and so they prevent the emission of formaldehyde. Another positive influence of HC for adhesive curing is an acid reaction medium (HC was added as water solution with pH = 5.2). Acid curing agents increase the rate of formation of both types of cross-links, and at markedly influence transformation of dimethylenether cross-links into methylene ones. Similar experiments were carried by LANGMAIER et al. (2004, 2005). They applied non-isotherma gravimetry to study the condensation kinetics of dimethylol-urea (DMU) with urea and with the hydrolysate (H) of chrome tanned leather waste. Authors stated that addition of a mass fraction 0.05 H to DMU reduces a rate of formation of unstable dimethylene ether cross-links in favor of more stable methylene bonds by 20–30 %. Hydrolysate lowered ratio of oxy–methylene bonds to methylene bonds in favor of methylene bonds at a ratio of about 1: 2. This was detected also at curing in neutral environment. We assume that glutaraldehyde included in activator AG is incorporated into cured adhesive structure and replaces dimethylen-ether cross-links with its 5-carbon chain. The 46
chain is not hydrolytically degraded. Hydrolysis is well known for unstable dimethylen-ether bonds and results in formaldehyde emissions from cured resin. MAMINSKI et al. (2006) studied a possibility to improve adhesive properties and properties of hardener using glutaraldehyde. They stated hypothesis, that glutaraldehyde added will form 5-carbon crosslinks in the adhesive network; this way also water resistance of adhesive can be improved. When summing all the experiments, we can say that simultaneous presence of both components (activator AG based on glutaraldehyde, and collagen hydrolysate HC) gives the best environment for curing and good results from the point of view of content and emissions of formaldehyde (fig. 2). 100 100 fd content - relative value (%) 80 60 40 20 fd emissionrelative value (%) 80 60 40 20 0 HrR Hr1 Hr3 0 HrR Hr1 Hr3 UF adhesive mixture UF adhesive mixture adhesive without HC adhesive with 5 % HC adhesive without HC adhesive with 8 % HC Fig. 2 Content of formaldehyde in plywood and emissions of formaldehyde when various UF adhesive mixtures were used CONCLUSION In conclusion we can say that: • the best results of formaldehyde content in plywood were achieved by UF adhesive mixture containing Hr3 and 5 % HC, • the lowest emission from glued material was measured at UF adhesive mixture with Hr3 and 8 % HC. Simultaneous presence of both components in the UF adhesive mixture both reduced the amount of formaldehyde in plywood, and reduced the formaldehyde emission from cured UF adhesive film. As for the UF adhesives are widely used, utilization of secondary raw materials (skin collagen hydrolysates) in adhesive production can positively influence the environment and be economically interesting. Acknowledgments This paper was worked out in the frame of the project VEGA 1/0517/09 and projects APVV- 0521-07 and APVV-0773-07. REFERENCES 1. LANGMAIER, F. et al. 2004. Curing of urea-formaldehyde adhesives with collagen type hydrolysates under acid condition. In Journal of Thermal Analysis and Calorimetry. 2004, 76, p. 1015-1023. 2. LANGMAIER, F. et al. 2005. Curing urea-formaldehyde adhesives with hydrolysates of chrome-tanned leather waste from leather production. In International Journal of Adhesion and Adhesives. 2005, 25, p. 101-108. 3. MAMINSKI, M.L., PAWLICKI, J., PARZUCHOWSKI, P. 2006. Improved water resistance and adhesive performance of a commercial UF resin blended with glutaraldehyde. In The Journal of Adhesion. ISSN 0021-8464, 2006, 82, p.629-641. 47
Page 1 and 2: Annals Warsaw University of Life Sc
Page 3 and 4: ZIELIŃSKA-SZWAJKA JOANNA, GÓRSKI
Page 5: Board of reviewers: Bogusław Bajko
Page 8 and 9: analysis done on its base are one o
Page 10 and 11: On the base of the analysis, we sug
Page 12 and 13: Annals of Warsaw University of Life
Page 14 and 15: and analyzed on the level of tax ad
Page 16 and 17: REFERENCES: 1. Daňové trestné č
Page 18 and 19: description, selection and systemat
Page 20 and 21: Tab. 4 Regional foreign direct inve
Page 24 and 25: Опытные образцы пр
Page 26 and 27: EXPERIMENTAL PART The experimental
Page 28 and 29: 6. HENDARTO, B., SHAYAN, E., OZARSK
Page 30 and 31: Fiber direction - longitudinal Ra b
Page 32 and 33: Thickness of the paint coating film
Page 36 and 37: ises, together with its value, that
Page 40 and 41: Similar experiments were carried by
Page 42 and 43: CONCLUSION Based on the evaluation
Page 48 and 49: 4. PARK, B.D., LEE, S.M., ROH J.K.
Page 50 and 51: plywood pressing). Spectra of liqui
Page 52 and 53: confirmed by the fact that the peak
Page 56 and 57: RESULTS AND DISCUSSION The obtained
Page 58 and 59: Streszczenie: Emisja VOC z filmów
Page 60 and 61: particleboards of 18 mm thickness l
Page 62 and 63: laminated particleboards released f
Page 66 and 67: of a rubber granulate mat, adhered
Page 68 and 69: Type of tests point I III III I III
Page 72 and 73: Parameter, unit Application method
Page 74 and 75: 3.2 Graph 3. Shear strength of glue
Page 76 and 77: property that is not directly inclu
Page 80 and 81: Die Idee, alte Papiere umzuarbeiten
Page 84 and 85: Table 1. Results of hardness tests
Page 86 and 87: cause faster and less even wear of
Page 90 and 91: CH 2 OH CH CH 2 CH 2 OH CH CH 2 CH
Page 94 and 95: supply increment of the ,,j” prod
Page 96 and 97:
Annals of Warsaw University of Life
Page 98 and 99:
Basierend auf der Umfrage ergaben s
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Bild 7. Standzeitdiagram - Vorschub
Page 102 and 103:
ANWENDUNGEN Die Ergebnisse dieser S
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Verhältnis der maximale Durchmesse
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Basierend auf der Umfrage, für die
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drills are described in the work of
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Calculation of the thrust force and
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CONCLUSION The idea of considering
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Fig. 4. Relationship between cuttin
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life observed for MDF is longer tha
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Table 1. Types and characteristics
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ACKNOWLEDGEMENT Investigations were
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That is why a proper treatment seem
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CONCLUSIONS 1. Treatment of oil pal
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максимальной степе
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REFERENCES: 1. Шубин Г.С. Ф
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MATERIAL AND METHODS Used method We
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TVOC emitted by various kind of woo
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tensile force the dynamics of these
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Streszczenie: Gęstość drewna wia
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it was attempted in this study to a
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Cameron and Dunham [1999], when com
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unstable joints made of metal were
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Photo 8. View of an incorrect joint
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called CORDA, while the lowest cont
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willow clone, whereas the clone des
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Fig.2. Modulus of rupture of partic
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a) P, % 100 90 80 70 60 50 40 30 20
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the connection, and too little surf
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■ Multidimentional air stream wit
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Fig. 2. Proportion of elements in l
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2. The highest efficiencies were fo
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Characteristic values of annual inc
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CONCLUSIONS The following conclusio
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that of particleboards with the cor
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Streszczenie: Właściwości eksper
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across the fibres on two counterpar
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CONCLUSION Obtained results allow t
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chamber PW 10 from firm HAMECH in H
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Fig.4. RMS of F w during milling of
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Fig.4. Influence of modification on
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Fig. 2. Changes in breaking length
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Fig.5. Changes in tear strength of
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e) f) Fig. 1 Thickness changes of v
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REFERENCES 1. KAFKA, E. a kol., 198
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produce underground rhizomes and it
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It results from a comparison of the
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Alternatywne źródła energii. Dob
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качества при длите
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3 Ширина годичного
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Table 2. Basic parameters of applic
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Table 5. Test results (average valu
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a) 6 weeks 12 weeks b) 3 months 7 m
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- PN ISO 7724−2:2003 Farby i laki
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