Autocondensation-based, zero-emission, tannin adhesives for particleboard

Pizzi, A.; Meikleham, N.; Dombo, B.; Röll, Werner

doi:10.1007/bf02716424

Cited by 73 publications

(57 citation statements)

References 5 publications

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“…Thus, the shaves can adsorb higher amounts of water during storage. This assumption is confirmed by results of Pizzi et al (1995a) who fabricated tannin bonded particle boards by adding To discuss the big differences in strengths between the samples (B), (C) and (D) ( Table 1) the addition of boron compounds and the different drying processes have to be taken into account. Because, samples (C) and (D) were similarly dried and stored the addition of boron compound to HSB (C) during fabrication can lead to higher values of strengths compared to (D).…”

Section: Drying Process and Strength Propertiesmentioning

confidence: 82%

“…Due to the formaldehyde (CH 2 O) toxicity (Yusuf et al 1995;Yalinkilic et al 1999 This indicates very low release of CH 2 O-molecules (Pizzi et al 1994;Pizzi et al 1995a;Heinrich et al 1996) and that the boards are well within the limits of the E1 emission class (Marutzky 1989). Comparing samples (C) and the control samples shows that the used mimosa tannin has no influence on the formaldehyde emission.…”

Section: Release Of Formaldehyde and Fire Protectionmentioning

confidence: 99%

“…This will be done by boron compounds which are capable of acting as both as an insecticide and a fungicide (Thevenon et al 1997). In addition, using borates should lead to boards with higher strengths compared to a non addition boards (Pizzi et al 1995a) and offer great advantages for applications including no or very low mammalian toxicity, low volatility, they are colourless and odorless (Yalinkilic et al 1999;Murphy 1990). Because, the boards thought to be used in particular in dry environments a possibly small but sufficient addition of the fungicide should be used.…”

Section: Introductionmentioning

confidence: 99%

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Biodegradable lightweight construction boards based on tannin/hexamine bonded hemp shaves

Theis¹,

Grohe

2002

Holz als Roh- und Werkstoff

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Interior grade hemp shave lightweight construction boards of about 0.260 g/cm 3 , with a dry I.B. strength of up to 0.34 MPa, a formaldehyde release well within the emission class E1 and certificate as normal flammable and not burning dripped off (DIN 4102-B2) were fabricated by mixing hemp shaves with a borate-modified mimosa tannin-hexamine binder and press the masses as fast as 6 s/mm thickness at 70°C to one-layer boards. Different drying processes indicate that fast drying at 100°C is needed both for satisfactory strengths and for a sufficient dimension stability performance of soaked samples, but, as well for a lower boron leaching during soaking. For dry environments the resistance to fungal attack is sufficient enough to have boards for interior application. Biologisch abbaubare Leichtbauplatten basierend auf Tannin/Hexamin gebundenen HanfschäbenHanfschäben wurden mit Borat modifizierten Mimosa Tannin-Hexamin Bindern gemischt und bei 70°C und Presszeiten von 6 s/mm Dicke zu einlagigen Leichtbauplatten mit Dichten von etwa 0.260 g/cm 3 verpresst. Querzugfestigkeiten bis zu 0.34 MPa, Formaldehyd-Emissionen die innerhalb der Emissionsklasse E1 liegen und Brandschutzeinstufungen als normal entflammbar und nicht brennend abtropfend (DIN 4102-B2) wurden bestimmt. Verschiedene Trocknungsprozesse zeigen, dass schnelles Trocknen bei 100°C zu höheren Festigkeiten und, nach wässern der Proben, zu ausreichender Dimensionstabilität bei geringerer Borauswaschung führt. Für trockene Umgebungen ist die Resistenz gegen Pilzbefall ausreichend genug um die Bretter für Innenanwendungen einzusetzen.

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Section: Drying Process and Strength Propertiesmentioning

confidence: 82%

Section: Release Of Formaldehyde and Fire Protectionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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Biodegradable lightweight construction boards based on tannin/hexamine bonded hemp shaves

Theis¹,

Grohe

2002

Holz als Roh- und Werkstoff

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“…Entre estes produtos, podem ser citados, a lignina, o tanino e a farinha de soja. Assim, resinas livres de formaldeído, como taninos condensados (KAMOUN et al, 2003;PICHELIN et al, 2006;PIZZI, 1994;PIZZI et al, 1995), ligninas (EL MANSOURI et al, 2007a;EL MANSOURI et al, 2007b;LEI et al, 2007;PIZZI, 2006), óleos vegetais (PIZZI, 2006) e proteína e farinha de sojas (LIU;LI, 2007;LORENZ et al, 2006;WESCOTT et al, 2006) têm sido propostas.…”

Section: Materiais Naturaisunclassified

“…Algumas destas resinas já estão em uso industrial e apresentam um bom desempenho, ou seja, os adesivos de tanino PIZZI,1994;PIZZI et al, 1995;PIZZI, 2006), porém a fonte destes está limitada. Sua utilização é de interesse para o uso de materiais alternativos ou para co-reação com outros materiais mais abundantes e livremente mais disponíveis, tais como a farinha de soja e a lignina para estender seu uso.…”

Section: Resinas Utilizadas Industrialmenteunclassified

Estudo cinético da oxidação de ligninas obtidas da palha e do bagaço de cana e aplicações de lignina de bagaço em resina a base de materiais naturais

Amaral-Labat¹

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Comparative kinetics of the induced radical autocondensation of polyflavonoid tannins. II. Flavonoid units effects

Masson¹,

Pizzi²,

Merlin³

1997

J. Appl. Polym. Sci.

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ABSTRACT:Comparative kinetics of the radical autocondensation induced by SiO 2 on a series of polyflavonoid tannins, namely, pine, pecan, mimosa, quebracho, gambier, sumach, and on the catechin monomer as a model compound were carried out by electron spin resonance. The induced radical autocondensation appeared to be independently catalyzed by the known base mechanism, as well as SiO 2 and Lewis acid attack directly at the heterocycle oxygen. The reaction occurs in two definite steps: the first, the radical-anion formation, the second, the condensation proper with other flavonoid units of the reactive sites formed. The rate determining step depends on both the main flavonoid unit structure of each tannin and particularly on the level of colloidal state of the tannin solution and the number-average degree of polymerization (DP n ), with the latter two parameters being the main determining ones for the second reaction step and the first two for the first reaction step. It is, however, the combination of the three parameters that determines the total observable effect for each of the flavonoid tannins. The SiO 2 attack at the heterocycle ether oxygen is of such an intensity that the A-rings' phenoxide radicals, which drive the reaction, surge very rapidly to such a higher proportion than the B-rings phenoxide radicals that the B-rings also start to surge later by shifting to the left of the • B _ A• equilibrium. There are also indications that ionic mechanisms might be more important for the second step of the reaction. Different radical-anion species and the relative movements of the relevant equilibria involved can be clearly identified from the spectra peaks. The initial, maximum intensity of the peaks has been shown to be the parameter defining the first step of the reaction, while the radical decay rate has been shown to refer to the second step of the reaction. Hydrolyzable tannins have been shown not to undergo neither any silicainduced radical surge nor autocondensation as predictable from their structures.

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Autocondensation-based, zero-emission, tannin adhesives for particleboard

Cited by 73 publications

References 5 publications

Biodegradable lightweight construction boards based on tannin/hexamine bonded hemp shaves

Biodegradable lightweight construction boards based on tannin/hexamine bonded hemp shaves

Estudo cinético da oxidação de ligninas obtidas da palha e do bagaço de cana e aplicações de lignina de bagaço em resina a base de materiais naturais

Comparative kinetics of the induced radical autocondensation of polyflavonoid tannins. II. Flavonoid units effects

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