An investigation into commercially feasible applications of ellagic acid and its derivatives
- Authors: Przewloka, Simon
- Date: 1999
- Type: Text , Thesis , PhD
- Full Text:
- Description: "Significant quantities of ellagic acid and its metal salts, in the form of waste byproducts, are readily available from both the pulping and tanning industries should a feasible commercial use for the acid (1) be found. The purpose of this work was to prepare key derivatives of ellagic acid and assess their feasibilty for use on a commercial scale. To accomplish this, it was first necessary to prepare ellagic acid in high yield."
- Description: Doctor of Philosophy
Effects of ellagic acid and derivatives thereof on water repellency and dimensional stability
- Authors: Przewloka, Simon , Shearer, B. J.
- Date: 2008
- Type: Text , Journal article
- Relation: Journal of Tropical Forest Science Vol. 20, no. 2 (2008), p. 132-138
- Full Text: false
- Reviewed:
- Description: Derivatives of the insoluble polyphenolic ellagic acid and water soluble tetraguanidinium, tetracholine, tetrakis-benzyltrimethylammonium and tetrakis-tetramethylammonium ellagates and 2,3,4,2',3',4'-hexamethoxy-6,6'- diisocyanato-diphenyl, were prepared. The effects of these compounds upon water repellency and dimensional stability when impregnated into timber were examined. Water soluble ellagates improved water repellent effectiveness up to 32%. Ellagic acid and 2,3,4,2',3',4'-hexamethoxy-6,6'-diisocyanato-diphenyl increased initial swelling rates due to their solvent carriers. All trial compounds provided the timber wafers with additional dimensional stability predominantly by non-bonded, non-leachable bulking. Generally a reduction in the extent but not the rate of moisture uptake was noted for the compounds investigated.
- Description: C1
The further chemistry of ellagic acid I. Synthesis of tetramethylellagic acid and associated polymer precursors
- Authors: Reitze, J. D. , Przewloka, Simon , Shearer, B. J.
- Date: 2001
- Type: Text , Journal article
- Relation: Holzforschung Vol. 55, no. 2 (2001), p. 171-175
- Full Text: false
- Reviewed:
- Description: A quantitative method for the production of 3,3',4,4'-tetra-O-methylellagic acid was developed. Ellagic acid was fully methylated under nitrogen and in air using dimethyl sulphate and 25%,guanidinium methoxide in N-methyl-2-pyrrolidone. The synthesis of a range of polymer precursors derived from 3,3',4,4'-tetra-O-methylellagic acid are outlined, including the previously unreported 2,3,4,2',3',4'-hexamethoxy-6,6'-diphenoyl-dichloride, 2,3,4,2',3',4'-hexamethoxy-6,6'-diisocyanto-diphenyl, 2,3,4, 2',3',4'-hexamethoxy-6,6'-diamino-diphenyl, 2,3,4,2',3',4'-hexamethoxy6,6'-dihydroxymethyl-diphenyl and 2,3,4,2',3',4'-hexamethoxy-diphenyl-6,6'-dialdehyde.
The further chemistry of ellagic acid II. Ellagic acid and water-soluble ellagates as metal precipitants
- Authors: Przewloka, Simon , Shearer, B. J.
- Date: 2002
- Type: Text , Journal article
- Relation: Holzforschung Vol. 56, no. 1 (2002), p. 13-19
- Full Text: false
- Reviewed:
- Description: Preparations of the previously unreported, water-soluble, tetraguanidinium, tetracholine and tetrakisbenzyltrimethylammonium ellagates are outlined. Ellagic acid and these water-soluble salts remove Mg2+, Ca2+ and Mn2+ ions from dilute aqueous solutions at pH greater than 7. The salts also remove Fe2+, Fe3+, Co2+ and Cu2+ between pH 3 and pH 6. At pH 1 the water-soluble ellagates underwent hydrolysis, resulting in the precipitation of free ellagic acid in preference to the formation of metal-ellagate complexes. These trends were also observed when mixtures of metal ions were applied.
- Description: 2003000160
The further chemistry of ellagic acid III: The effect of wick action upon moisture uptake and movement in ellagate treated Pinus radiata wood
- Authors: Przewloka, Simon , Shearer, B. J.
- Date: 2002
- Type: Text , Journal article
- Relation: Holzforschung Vol. 56, no. 6 (2002), p. 632-638
- Full Text: false
- Reviewed:
- Description: Pinus radiata sapwood stakes were treated with ellagic acid and tetraguanidinium, tetracholine and tetrakis-benzyltrimethylammonium ellagates. The effect of these treatments upon moisture movement and uptake was investigated by wick action. Given that chemical reactions within the wood substrate between nutrients and treatment solutions may alter the properties of the wood with regard to moisture movement, the presence of Cu2+ in the system was also examined. Water-soluble ellagates reduced water loss by 25-35 %, but had no effect upon water uptake. Ellagic acid in N-methylpyrrolidone significantly reduced both water loss and moisture uptake. The effect of Cu2+ upon moisture movement and uptake in the treated stakes was negligible.
- Description: 2003000162