FLAME RETARDING OF WOOD BY CHEMICAL MODIFICATION WITH BROMATE-BROMIDESOLUTIONS

In spite of the extensive and diversified uses of wood and wood produc ts for millenia, there are still a number of basic deficiencies of the se products which limit their use and pose difficult and as yet not sa tisfactorily solved problems to the engineer and consumer. The most pr ominent of these problems are: flammability, dimensional stability, an d fungal attack. Review of work carried out at the Israel Fiber Instit ute indicates that treating solid timber and polywood with acidified b romate-bromide solutions is capable of overcoming these deficiencies t o a large extent. The treatment is carried out in autoclaves with appl ication of vacuum and pressure. The lignin component of the wood is br ominated in the solid state by the treatment solution with a high yiel d of bromine. The mechanical properties of the treated products are un changed. The treatment is stable to prolonged leaching, aging, and sto rage. Water absorption and swelling are drastically decreased-dimensio nal stabilization. The brominated products are shown not to be attacke d by wood fungi.