EFFECTS OF ELLAGIC ACID AND DERIVATIVES THEREOF ON WATER REPELLENCY AND DIMENSIONAL STABILITY

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.