Research On Fungi-Resistant Poplar OSB

Research and development of Poplar-based oriented strandboard (OSB) will stimulate the effective and efficient uses of fast-growing poplar wood, the development of value-added OSB products and protection technology of wood-based panels as well. In order to develop polar OSB with decay and mold-resistant ability, seven preservatives, being Borate, Plygurad (PA), CuAz, naphthenate, TBQ, MA and MB, were selected and added at different levels to the three resin systems (UF, PF, MDI) to evaluate their effects on the properties of resins, the board mechanical properties and board fungi-resistant ability of poplar OSB as well. The leachability of preservatives were also determined by atomic absorption spectroscopy (AAS ) for MDI bonded OSB.The research results showed that:(1) Preservatives additions did affect the properties of resins more or less. Both Borate and PA had very little influences on the pH of PF resin, but Borate addition increased the contact angle and velocity while PA acted in another way. Both them decreased the curing time of PF resin. The addition of MA , MB and PA decreased the contact angle of UF resin and affected the pH little, but MA and MB decreased the velocity and increased the curing time of UF resin.(2) Poplar OSB treated with Borate had not only had excellent mechanical properties, but also performed outstanding at the decay-resistant test at the lowest addition level of 0.5%; boards treated with PA and naphthenate presented satisfied decay-resistant performance only at high addition level while the boards treated with lab-made CuAz had no improved decay-resistant performance though their mechanical properties were satisfied;(3) Borate and TBQ with high addition level were suggested to produce MDI bonded high performance fungi-resistant poplar OSB, while the middle and high addition level of PA showed good mold-resistant ability and naphthenate was a good choice to produce decay-resistant MDI bonded OSB products.(4) The 1% content level of MA and the 0.75% loading level of MB were suggested to adopted to produce UF bonded mold-resistant poplar OSB, for their both excellent mechanical properties, their minor effects on UF resin and their outstanding mold-resistant performance;(5) The fitting curve of long-term and short term mold-resistant efficacy determined that there was a good relationship between them.