SYNTHESIS, CHARACTERIZATION AND EFFECTIVENESS OF BIGUANIDE DERIVATIVES OF BORIC-ACID AS POTENTIAL FIXED-BORON WOOD PRESERVATIVES

The biguanide derivatives of boric acid, BBC [1] and BGB [2] have been shown to have fungitoxic properties when tested in radiata pine sapwo od against three fungi, but only in non water leached wood blocks. On water leaching, the water soluble heterocyclic compounds, despite exhi biting extensive intermolecular hydrogen bonding, dissolved and were l ost from the wood. BGB [2] could be successfully polymerised by an aci d-catalysed condensation reaction with HNNM in order to fix the boron heterocycle in a water-insoluble form. Bioassay of this polymeric prod uct in both unleached and leached radiata pine sapwood treated at the highest retention (0.6% boric acid equivalent) showed that the antifun gal properties were largely retained against two out of the three fung i tested.