Covalent bonding of wood through chemical activation

The reaction of softwood thermomechanically pulped fibres with succinic anhydride (SA) and its subsequent reaction with hexamethylene diamine (HMDA) were examined, the latter employing the coupling agents dicyclohexylcarbodiimide, or diisopropylcarbodiimide. FTIR and 13C NMR studies showed amide linkages were produced between SA modified fibres and the diamine. Wood veneers were covalently bonded using this technology. It was found that during hot pressing bonding occurs between SA treated veneers and HMDA without the need for a coupling agent.