Abstract:

Chitosan, a natural and renewable polymer without toxic and pollution to human beings and environment and the deacetylated derivative of chitin that mainly exist in the crusts of crabs and shrimps, has many good characteristics and used into many fields such as agriculture, medicine, chemistry, etc.Chitosan metal complex (CMC), one new potential wood preservative, which produce from the chemical reaction between chitosan and some metal salts such as copper or zinc salts are shown to be effective but low-toxicity preservatives for wood. This paper reported the decay resistance of Pinus massoniana and Populus tomentosa treated with chitosan copper/zinc complex (CCC and CZC)against the brown and white rot fungi. The results showed that the decay resistance of CZC against brown rot fungi (Poria placenta) treated to P. massoniana wood were equivalent with CCA, and remarkably better than that of only treated by relevant metal salts and chitosan, but CCC had little effectiveness against brown rot fungus. The threshold retention of zinc ion in CZC treating solution was 0.780 kg·m^-3 (mass loss 1.18); also decay resistance of CCC against white rot fungi (Coriolous versicolor) was equivalent with CCA, and remarkably better than that of only treated by relevant metal salts and chitosan, while the CZC against white rot fungi was not good. The threshold retention of copper ion in CCC treating solution was 0.824 kg·m-3 (mass loss 2.45).

Key words: Chitosan metal complex, Populus tomentosa, Pinus massoniana, Decay resistance