Quality of Oleoresinous Wood Vanish Prepared using Resin Synthesized from Tannin Extracted from Stem Bark of Khaya senegalensi
Asian Journal of Applied Sciences (ISSN: 2321 – 0893)
Volume 02 – Issue 01, February 2014
Quality of Oleoresinous Wood Varnish Prepared using Resin
Synthesized from Tannin Extracted from Stem Bark of Khaya senegalensis Osei Akoto1 and Anthony Osei-Brefoh2
1
Department of Chemistry,
Kwame Nkrumah University of Science and Technology
Kumasi, Ghana
2
Department of Chemistry,
Kwame Nkrumah University of Science and Technology
Kumasi, Ghana
_________________________________________________________________________________________________
ABSTRACT---- Phenol is used as a starting material in the preparation of wood varnish. In this work efforts were made to substitute phenol from tannins extracted from the stem bark of Khaya senegalensis to produce wood vanish and assessed its quality. An extract with a Stiasny Number of 87.88 % and extractable phenols of 2.82 mg/kg was used to synthesize a phenol-formaldehyde called tannin-formaldeyde. Properties of this resin were compared with that of phenol-formaldehyde resin synthesized using a commercially available phenol following the same procedure. A yield of 89.82% for phenol-formaldehyde resins showed a good and efficient method of synthesizing the resins. The study indicated that tannin-formaldehyde resins had better solubility in linseed oil than phenol-formaldehyde resin. A darkbrown viscous resole-type phenolic resin was produced from tannin extract as against a yellow viscous resin for commercial phenol. the colour of the Subsequently, unfortified oleoresinous wood varnish (solutions of one or more natural or synthetic resins in a during oil and volatile solvent) of high gloss, good chemical resistance and good drying time paralleling each other were readily prepared from both resins. Varnish made from phenol-formaldehyde and tannin-formaldehyde resins had acid numbers of 9.9 mg KOH/g and 8.6 mg KOH/g varnish respectively: both falling within the 0.2-10.5 range for most satisfactorily
Volume 02 – Issue 01, February 2014
Quality of Oleoresinous Wood Varnish Prepared using Resin
Synthesized from Tannin Extracted from Stem Bark of Khaya senegalensis Osei Akoto1 and Anthony Osei-Brefoh2
1
Department of Chemistry,
Kwame Nkrumah University of Science and Technology
Kumasi, Ghana
2
Department of Chemistry,
Kwame Nkrumah University of Science and Technology
Kumasi, Ghana
_________________________________________________________________________________________________
ABSTRACT---- Phenol is used as a starting material in the preparation of wood varnish. In this work efforts were made to substitute phenol from tannins extracted from the stem bark of Khaya senegalensis to produce wood vanish and assessed its quality. An extract with a Stiasny Number of 87.88 % and extractable phenols of 2.82 mg/kg was used to synthesize a phenol-formaldehyde called tannin-formaldeyde. Properties of this resin were compared with that of phenol-formaldehyde resin synthesized using a commercially available phenol following the same procedure. A yield of 89.82% for phenol-formaldehyde resins showed a good and efficient method of synthesizing the resins. The study indicated that tannin-formaldehyde resins had better solubility in linseed oil than phenol-formaldehyde resin. A darkbrown viscous resole-type phenolic resin was produced from tannin extract as against a yellow viscous resin for commercial phenol. the colour of the Subsequently, unfortified oleoresinous wood varnish (solutions of one or more natural or synthetic resins in a during oil and volatile solvent) of high gloss, good chemical resistance and good drying time paralleling each other were readily prepared from both resins. Varnish made from phenol-formaldehyde and tannin-formaldehyde resins had acid numbers of 9.9 mg KOH/g and 8.6 mg KOH/g varnish respectively: both falling within the 0.2-10.5 range for most satisfactorily
References: Asian Journal of Applied Sciences (ISSN: 2321 – 0893) Volume 02 – Issue 01, February 2014 [5] Dupuy, B., “Mixed plantations in Coˆte d’Ivoire rain forests”. Bois et Foreˆts des Tropiques, vol. 24, pp. 33-34, 1995. [10] Food and Agriculture Orgnization (FAO)/ IAEA, Working document (lab manual), quantification of tannins in tree foliage, IAEA, Vienna, pp.1-3, 2000. [12] Gardner, H. A. and Sward, G. G., Physical and chemical examination of paints, varnishes, lacquers and colours, Gardner Laboratory Incoporated, Maryland, 1978. [16] Marie-Pierre, L., Investigation of the wood/phenol-formaldehyde interphase morphology, PhD Thesis, Blacksburg, Virginia, 2002.