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Saturday, 30 July 2016

Assessment of surface properties and solvent-borne coating performance of red oak wood produced by peripheral planing

Published Date
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Title

Assessment of surface properties and solvent-borne coating performance of red oak wood produced by peripheral planing

  • Author
  • Bruna Ugulino
  • Roger E. Hernández

Abstract

Coating performance on wood could be affected for different aspects including the manner in which the surface is prepared. Peripheral planing is one of the most used machining processes in woodworking. Improving this process would allow to enhance coating performance. As a result, the effects of wavelength and rake angle on surface properties and coating performance were evaluated in an attempt to improve peripheral planing of red oak wood. Surface quality was assessed through roughness, scanning electron micrographs, and wettability analyses. The performance of a solvent-borne coating was measured by adhesion strength before and after accelerated aging. Surface roughness and energy components increased as rake angle increased. As wavelength increased, cell damage and surface roughness increased. Surfaces prepared with a rake angle of 25° had more cell-wall fibrillation, which was assumed to be responsible for increased surface energy and improved coating adhesion after weathering. Samples machined with this rake angle combined with a short wavelength resulted in the lowest loss of adhesion after aging and presented an acceptable level of surface roughness.

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For further details log on website :
http://link.springer.com/article/10.1007/s00107-016-1090-6

Antioxidant potential and content of phenolic compounds in extracts of twelve selected Malaysian commercial wood species

Published Date
First online: 

Title

Antioxidant potential and content of phenolic compounds in extracts of twelve selected Malaysian commercial wood species

  • Author
  • Roszaini Kadir 
  • Mike David Hale

Abstract

This study was performed to investigate the antioxidant values of twelve selected Malaysian wood species. Bark and heartwood were extracted with toluene: industrial methylated spirit (Tol: IMS) and evaluated for antioxidant activity. Folin–Ciocalteu reagent was used to determine the total antioxidant activity and total phenols of plant extracts. Free radical scavenging activity was evaluated using 2,2-dipheny-2-picrylhydrazyl (DPPH). Extractive yields, antioxidant activity and total phenolic content varied among wood species. N. heimii had the highest extractive yields (23.50 and 9.16 %), antioxidant (93.60 and 83.78 %) and total phenolic content (29.11 and 24.11 mgGAE/g) for bark and heartwood, respectively. The results provided promising evidence that those tropical timbers may be useful as potential sources of natural antioxidants and could be used as drug formulations.

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For further details log on website :
http://link.springer.com/article/10.1007/s00107-016-1095-1

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