Laia Haurie, Universitat Politècnica de Catalunya, presented tests of resin-impregnation of wood, with the objective of developing flame retarded wood-plastic composites. Two phosphorous flame retardants were added to an unsaturated polyester resin and compared with a chlorinated unsaturated polyester resin. Wood samples were impregnated in a vacuum and pressure process in an autoclave and cured by means of gamma-radiation.
The wood plastic composites tested exhibit an improvement in some properties, such as mechanical behaviour. The phosphorous-based resins promote charring, but their fire performance is lower than for the chlorinated resin. Both resin-impregnated woods showed higher smoke emission than non-impregnated wood, with higher smoke production from the chlorinated resin.
Osman Emre Özkan, Kastamonu University, Turkey, presented testing of a process to fix inorganic PIN FRs in wood to reduce leaching in outdoor construction applications. Pine wood was impregnated with aqueous solution of the FRs (diammonium phosphate, borax, boric acid) and glucose, then heated at 120-180°C for fixing by polymerisation. Results show that the fixed PIN FRs slow the decomposition of wood in fire, and reduce leaching of phosphorus.