Use of alkyl ketene dimer (AKD) for surface modification of particleboard chips

Hundhausen, Ulrich; Militz, Holger; Mai, Carsten

doi:10.1007/s00107-008-0275-z

Cited by 35 publications

(44 citation statements)

References 17 publications

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“…This indicates that AKD can be partially bonded on the chips under the applied curing conditions. These results comply with previous findings of extraction studies in combination with FTIR analyses (Hundhausen et al 2009a).…”

Section: Ftir Analysessupporting

confidence: 93%

PF-bonded particleboards from AKD-modified chips

2009

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Alkyl ketene dimer (AKD) was used as a hydrophobic agent for PF-bonded particleboards. In contrast to conventionally used paraffin, AKD can be covalently bonded to the chip surface by esterification with wood hydroxyl groups. FTIR analyses before and after toluene extractions indicated that only a small amount of the applied AKD is chemically bonded. Wettability studies on veneer strips suggested that particularly the bonded AKD accounts for the surface hydrophobicity.A subsequent spraying of AKD and PF resin on the chips that were pressed for 15, 30, and 60 s mm −1 (Process 1) did not result in decreased thickness swelling and water uptake as compared to the control boards. In Process 2, chips were cured (130• C/6, 12, 24 h) prior to pressing (15 s mm −1 ) which did not impart significant hydrophobicity either. The low efficacy of AKD as hydrophobic agent in Process 1 is attributed to the hydrolysis of AKD by water vapor during pressing. The low hydrophobic effect of AKD in Process 2 is ascribed to a saponification of esters between AKD and wood hydroxyl groups by the alkaline PF resin.

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Section: Ftir Analysessupporting

confidence: 93%

PF-bonded particleboards from AKD-modified chips

2009

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“…The results coincided with previous findings that indicated a low hydrophobic effect of AKD when it was applied after being mixed with UF resin (Hundhausen et al 2008). Four potential reasons have been proposed.…”

Section: Processsupporting

confidence: 90%

“…• C for 24 h prior to board production (Hundhausen et al 2008). In comparison, the admixture of AKD to UF glue did not have any great effect.…”

Section: Introductionmentioning

confidence: 79%

“…Microscopic analysis showed that nearly all glue droplets contained emulsified paraffin particles. Assuming that a patchwork-like pattern is formed on the chip surface, Hundhausen et al (2008) have proposed that a similar mechanism occurs when AKD is mixed with UF resin. It was implied that pressing times over 12 s mm −1 make the esterification of AKD possible which is located between the dried adhesive.…”

Section: Processmentioning

confidence: 99%

“…Alkyl ketene dimer (AKD) has been shown to improve dimensional stability of particleboards (Hundhausen et al 2008). Contact angle and drop extension measurements on AKD-treated veneer strips have revealed strongly reduced surface wettability.…”

Section: Introductionmentioning

confidence: 99%

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Procedural influence on the properties of particleboards made from AKD modified chips

et al. 2009

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Wood chips were treated with alkyl ketene dimer (AKD) using three different processes to impart water resistance to particleboards. In the first process, AKD was blended with UF resin. Thickness swelling and water uptake after a 24 h immersion period (20 and 69%) were lower than in the control boards (28 and 81%) but were higher than in the paraffin references (10 and 22%). In process 2, AKD and UF resin were sprayed separately on the chips resulting in a greater reduction of thickness swelling (15%) and water uptake (49%) than in process 1. Paraffin references revealed a thickness swelling and water uptake of 7 and 25%, respectively. An extension of the pressing time in processes 1 and 2 did not increase water repellence. In process 3, particleboards were made from AKD-treated chips that were cured at 130• C (24 h) prior to gluing. They showed a thickness swelling of 7% and a water uptake of 25%, whereas particleboards with paraffin exhibited levels of 8 and 29%. The thickness swelling and water uptake of boards with AKD increased when the curing time was reduced from 24 to 12 to 6 h (130 • C). Changing the curing temperature from 130 to 100• C (12 h) had no effect on board properties. The IB of boards made from pre-cured chips with AKD (24 h/130• C) was 44% lower than in controls and 35% lower than in paraffin references. This indicates that AKD impedes the adhesion.

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Surface modification of lignin for applications in polypropylene blends

Atifi

Miao

Hamad

2017

J of Applied Polymer Sci

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The surface modification of wet‐milled softwood lignin produced with the LignoForce System was successfully carried out in a one‐step aqueous process. Different hydrophobic molecules, including cetyl trimethyl ammonium bromide, poly(ethylene oxide), polyethylene‐block‐poly(ethylene glycol), dodecenyl succinic anhydride, and alkyl ketene dimer (AKD), were investigated to design the hydrophobicity of lignin with the objective of improving the adhesion and compatibility in polymer blends composed of polar lignin particles and, for example, nonpolar polypropylene (PP). AKD, among all of the investigated approaches, proved to be the simplest and most effective for significantly increasing the contact angle of lignin while preserving the original micrometer size of wet‐milled, spray‐dried lignin particles. This treatment led to a noticeable improvement in the stiffness of lignin–PP composite blends, with an increase of approximately 15% in Young's modulus. The compatibility of the AKD‐treated lignin with PP was assessed through tensile strength measurements and blend morphology observation, whereas the mechanism of AKD interaction with lignin was investigated with contact angle measurement, differential scanning calorimetry, Fourier transform infrared spectroscopy, and 1H‐NMR spectroscopy measurements. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017, 134, 45103.

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Use of alkyl ketene dimer (AKD) for surface modification of particleboard chips

Cited by 35 publications

References 17 publications

PF-bonded particleboards from AKD-modified chips

PF-bonded particleboards from AKD-modified chips

Procedural influence on the properties of particleboards made from AKD modified chips

Surface modification of lignin for applications in polypropylene blends

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