木材防腐藥劑成分對木材真菌之抑制效能

Abstract

人類利用木材為建築材料，已有很長久的歷史，然而木材在高溫、潮濕的環境下很容易產生各種生物性的危害，因此，為確保木材製品的功能性與延長使用年限，防腐處理有其必要性並且具有經濟價值。近年來，由於環保意識、法規等的改變，木材防腐藥劑研發，逐漸轉變為以少量金屬化合物混合合成殺菌劑（Biocide）的趨勢，以降低金屬化合物的使用劑量及對環境低衝擊性。本研究首先評估銅化合物及合成殺菌劑唑化合物（Azloes）與烷基銨化合物（Alkyl ammonium compounds）防腐劑對於木材真菌抑菌之效能，後續試驗則探討藥劑間加乘效應（Synergistic effect）。由篩選試驗選定硫酸銅、Tebuconazole與DDAC 進行固態平版試驗，得到藥劑對6株菌株的最低抑制濃度（MIC）、半數抑制濃度（IC50）數值，瞭解藥劑的抑菌能力與趨勢。硫酸銅水溶液因溶解性高，故對試驗菌株的抑菌效果佳；合成殺菌劑則以Cyproconazole與Tebuconazole的MIC值低，抑菌效果為最佳；DDAC的MIC濃度高，故抑菌效果不佳。 此外，本研究利用兩種藥劑混合進行抑菌試驗，期能產生加乘效應達到更好的抑菌效果、降低使用劑量或環境保護等效應。試驗結果顯示，高濃度硫酸銅與低濃度Tebuconazole混合配方，對G. trabeum與P. placenta 2株褐腐菌、T. versicolor白腐菌及T. harzianum黴菌的抑菌效果產生明顯加乘效應；而高濃度硫酸銅與低濃度DDAC混合配方則對P. placenta褐腐菌及T. harzianum黴菌的抑菌效果產生加乘效應。

Wood has been used for millennium as an important construction materail and known to be easily deteriorated by insects and fungi when used in the wet and/or high humility conditions. Treatments with proper preservatives generally increase the durability and service life of wood products. Because of changes in the environmental protection policies and public health concerns, tendency to research and develpoment of wood preservatives have dramatically changed in the last decade. Preservatives used today is toward the combination of biocides with metal compounds to reduce the dosage required and lessen the impact to the environment. In this study, three copper compounds (copper sulfate, copper carbonate, and copper oxide) and five biocides (DDAC and azoles such as azaconazole, cyproconazole, propiconazole, and tebuconazole) were tested against six wood-rotting fungi to understand their antifungal performance based on the values of MIC, IC50 and A.I.. The results indicated that copper sulfate, due to its relative high water solubility, had the most effective activity against fungi tested among the copper compounds. Among the biocides, cyproconazole and tebuconazole appeared to be the most effective reagents against fungi tested due to their lowest MIC values. Comparatively, the MIC values of DDCA were the highest. Experimental results from the combinations of copper sulfate with biocides showed that the mixture of higher concentration of copper sulfate with low concentration of tebuconazole exhibited synergistic inhibitiory effects against G. trabeum, P. placenta and T. versicolor, and that the mixture of relatively higher concentration of copper sulfate with low concentration of DDAC also had synergistic effects against P. placenta and T. harzianum mold fungi.