Functional Synthesis Of Tree Extractives And The Application Of Wood Preservation

It is an important research direction that tree extractives are used as wood preservatives, because some compounds of tree extractives have good resistance to wood preservation fungi. Extractives were prepared from the bark and heartwood of Wild Siris (Maackia amurensis Rupr.et.Maxim) with water, methanol, acetone, chloroform and ether, respectively. The total extractives with all different solvents took up 12.59% (w/w) of the heartwood and 57.68% of the bark. Among the heartwood extractives, 25 compounds were identified by the analysis of GC/MS. Most of them are phenolic compounds, such as phenol, resorcinol, catechol, 2-methoxy-phenol, 3-methoxy-phenol etc. Besides, there are also a small amount of alkene, anthracene, phenanthrene and their derivatives. From the bark extractives of Wild Siris, 5 compounds were identified by the same method. They are fatty acid, fat and their derivatives etc., such as 9-hexadecenoic acid methyl ester and octanoic acid. Octanoic acid took up 3.826% of the chloroform extractive from the bark of Wild Siris, and 8.260% of the ether extractive.In this study, the resistance of 9-hexadecenoic acid methyl ester, phenol, catechol, resorcinol, triacontahexaene, 2-methoxy-l,2-benzenediol, octanoic acid to a white rot fungus (Paecilomyces variot Bainier), a brown rot fungus (Gloeophyllum trabeum), a soft rot fungus (Chaetomium globosum) and a penicillium fungus (Coriolus versicolor) were determined respectively by filter paper disk method on the basis of the mixtures resistance experiments. The results showed that 4% 9-hexadecenoic acid methyl ester is resistant to Penicillium. At 2% of the concentration, 9-Hexadecenoic acid methyl ester, Phenol, Triacontahexaene, 2-Methoxy-1,2-Benzenediol have no resistance to all the tested fungi. The resistance of resorcinol is high to the white rot fungus, low to the brown rot fungus and the penicillium fungus, and no effect to the brown rot fungus. Catechol is resistant to all of the 4 fungi. Its bioactivity to the fungi in turn is: to the brown rot fungus greater than the soft rot fungus, greater than the penicillium fungus, and greater than the white rot fungus. Octanoic acid has the best resistance to all the tested fungi and its bioactivity to the fungi in turn is: to the white rot fungus better than the brown rot fungus, better than the soft rot fungus, and better than the penicillium fungus. In order to improve the resistance of octanoic acid to wood decay fungi and the its applicability as a wood preservative, 6 imidazolines derivatives include 4 quaternary ammonium salt(OIQ) were synthesized:(1) (1-hydroxyethyl-2-heptylimidazolines, HOI);(2) (1-Aminoethyl-2-heptylimidazoline, EOI);(3) (1-hydroxyethyl-1- benzyl -2-heptylimidazolines, HOIB); (4) (1-hydroxyethyl-1- methyl -2-heptylimidazolines, HOIM);(5) (1-Aminoethyl-1- benzyl -2-heptylimidazoline, EOIB);(6) (1-Aminoethyl-1- methyl -2-heptylimidazoline, EOIM ).In Chemistry Abstract (CA), the same structure compounds with HOIB or EOIB have notbeen found.Then, the cultivation experiments were done by the suspension method of white rot fungusspore and brown rot fungus spore with HOIM, HOIB, EOIM, EOIB, ACQ-C, DDAC, ACC,BAC(1227) and CA-B separately. The results display that the resistance of HOIM and HOIB towhite and brown rot fungi is not good. The resistance of EOIM and EOIB to the white andbrown rot fungi is not as good as that of ACQ-C, DDAC, 1227 and CA-B, but better than thatofACC.By the method of wood block preservation in laboratory, we finished the wood block [(UssuriPoplar), (Populus ussuriiensis Kom.)] preservation experiments with EOIM, EOIB, ACQ-C,DDAC, ACC and CA-B to the white rot fungus and brown rot fungus.The wood decay resistance, leachability, toxicity to the environment, dimensional stability,modulus of elasticity, and color was determined. The results were as follows:1. To the white and brown rot fungi, the wood treated with 2% EOIB could meet the demand of Degreeâ…¡of preservation, and the wood treated with 4% EOIB could be ranked Degreeâ… .2. To the white rot fungus, the wood treated with 2% EOIM could meet the demand of Degreeâ…¡of preservation, and the wood treated with 4% EOIM reached Degree I . To the brown fungus, the wood treated with 2% EOIM could meet the demand of Degreeâ…¢of preservation, and the wood treated with 4%-6% EOIM reached Degreeâ…¡, and the wood treated with 8% EOIM reached Degreeâ… .3. To the white and brown rot fungi, the wood treated with 2% CA-B could meet the demands of Degreeâ… of preservation.4. To the white and brown rot fungi, the wood treated with 2% ACQ-C could meet the demands of Degreeâ… of preservation.5. To the white and brown rot fungi, the wood treated with 2% DDAC could meet the demands of Degreeâ… of preservation.6. To the white rot fungus, the wood treated with 2% ACC could meet the demands of Degree I of preservation. To the brown rot fungus, the wood treated with 2%-8% ACC could meet the demands of Degreeâ…¡of preservation and the wood treated with 10% could reach Degreeâ… .The leachability was 20.43% for ACQ-C, 17.23% for CA-B, 10.22% for EOIM, 10.05% for EOIB, 8.31% for DDAC and 7.57% for ACC. The safety concentration (mg·L^-1) is 2.47 for DDAC, 2.02 for EOIB, 0.625 for CA-B, 0.46 forACC and 0.01 for ACQ-C.The half lethal concentration [LC₅₀ /(mg·L^-1)] is 10.20(the time of operation at less than 24h)and 9.50(the time of operation above 48h ) for DDAC, 7.15 (less than 24h) and 7.01 (above48h ) for EOIB, 3.60(less than 24h) and 3.00(above 48h ) for CA-B, 3.20 (less than 24h) and2.50 (above 48h) for ACC, 2.59(less than 24h) and 0.66(above 48h ) for ACQ-C.The wood samples were impregnated with preservatives by vacuum and pressure method.Their bending strength and elastic modulus of bending was tested. According to the results, theorder of bending strength from high to low is EOIM, Control, ACC, CA-B, ACQ-C, DDACand EOIB and the elastic modulus of bending from high to low is EOIM, ACC, CA-B, ACQ-C,Control, EOIB and DDAC.The results of the treated wood dimensional stability are as follows:From oven-dry to air-dry, the line expansivity of the treated wood from high to low is CA-B,EOIB, Control, DDAC, ACC, EOIM and ACQ-C. The volume expansivity of the treatedwood from high to low is DDAC, EOIB, EOIM, ACQ-C, Control, CA-B, ACC.From oven-dry to sopping water, the line expansivity of the treated wood from high to low isControl, CA-B, EOIB, DDAC, EOIM, ACQ-C and ACC. The volume expansivity of thetreated wood from high to low is Control, ACC, DDAC, EOIM, CA-B, EOIB and ACQ-C.As the results from a mass of experiments and the research, some compounds of treeextractives have resistant ability to wood decay fungi. After functional synthesis, thecompounds of tree extractives are feasible to be used as wood preservatives in someenvironment. As a new type wood preservative, the tree extractives have the characters of nopollution to environment, innocuity to human and domestic animal. The compounds imitatenature. It is an effective approach to develope the new type wood preservetives by using themethod of functional synthesis compounds of tree extractives.