【作者】 曹永建；

【导师】 张双保； 段新芳；

【作者基本信息】 北京林业大学 ， 木材科学与技术， 2005， 硕士

【摘要】 以枫香、思茅松边材和心材纤维,杨木单板、漆酶和工业木素及其磺酸盐为主要原料,在试验室条件下,用漆酶处理木纤维压制纤维板,研究漆酶处理条件对纤维板的密度、吸水厚度膨胀率、内结合强度(IB)的影响;用漆酶活化木素及其磺酸盐后的胶合体系生产胶合板,研究漆酶处理条件对胶合板的胶合强度(shearing strength)的影响;利用电子自旋共振波谱技术(ESR)检测漆酶处理木材、漆酶活化木素及其磺酸盐的活性氧自由基(reactive oxygen species,ROS)变化规律与稳定性规律,揭示其胶合机理。为开发新型环保、无毒、绿色的人造板产品,实现无胶胶合,解决游离甲醛污染问题奠定基础。 研究结论如下: 1) 研究了三种木材纤维不同的漆酶处理条件与纤维板物理性能之间的相关性,找出了漆酶处理木纤维的最佳处理条件为pH3.0、时间2h、温度50℃、酶用量20u/g;在温度200℃,压力5～7MPa,时间15min的热压工艺条件下压制成密度0.88g/cm~3的纤维板,枫香纤维板比思茅松纤维板的IB强度高,IB值可达到1.26MPa。 2) 研究了不同漆酶处理活化木素及其磺酸盐的工艺条件与胶合板的胶合强度之间的相关性,漆酶分别处理木素及其磺酸盐的各自最佳条件不尽相同。漆酶在pH5.5,时间60min,温度25℃条件下处理木素磺酸铵,在温度150℃,压力4.5～5MPa,时间30min的热压工艺条件生产杨木胶合板,其胶合强度值最大,为0.76MPa。 3) 研究了不同处理条件下两种漆酶处理三种木材后的ROS变化规律、ROS的稳定性,ROS浓度变化与纤维板IB的相关性。漆酶处理木材的最佳条件为pH3.0、时间2h、温度50℃、酶用量20u/g;ROS在48h内缓慢减小,此后浓度急剧下降,第7天基本消失;ROS与IB二者之间呈正相关。更多还原

【Abstract】 In order to eliminate the pollution problem of formaldehyde, to developa new way for producing the wood composites without dissociative formaldehyde using laccase-treatment. Fibers of Liquidambar formasana, sapwood and heartwood of Pinus khasya var. langbianensis, veneers of Poplus tomentosa, laccases, lignin and salts of lignosulphonate were selected as materials, fiberboards were manufactured by laccase-treated on density, thickness expansion rate of water absorbing and internal bonding strength (IB) of fiberboard were measured; Plywood were manufactured using adhesive made by lignin and salts of lignosulphonate with laccase-treated, the effect of parameters of laccase-treated on the shearing strength of plywood was studied. The changes and stability of reactive oxygen species (ROS) and their bonding mechanisms of laccase-treated wood fibers, lignin and salts of lignosulphonate respectively were determined by ESR.The results shows that :1) The correlation between the conditions of laccase-treated to three kinds of wood and the physio-mechanics properties of fiberboard was analyzed. Result shows that the optimum parameters of laccase-treated wood fibers were at pH3.0, times 2h, temperature 50 ℃, laccase dosages 20u/g during the process of fiberboard manufacture. Under the hot-press parameters including temperature 200 ℃, press 5-7MPa and time 15 minutes, the IB of fiberboard at 0.88g/cm~3 density which was made of Liquidambar formasana wood is higher than that of Pinus khasya var. langbianensis, it reaches 1.26MPa.2) The correlation between the parameters of laccase-treated lignin and salts of lignosulphonate and the shearing strength of plywood was analyzed. Result shows that the optimum parameters of laccase-treated lignin and salts of lignosulphonate were different respectively. Ammonium lignin sulphonate was treated by laccase which be used as adhesive for plywood manufacture at pH5.5, time 60 minutes, temperature 25℃, the shearing strength of plywood of Poplus tomentosa wood reaches 0.76MPa under the hot-press parameters at temperature 150℃, time 30 minutes, press 4.5-5.0MPa.3) The changes and stability of ROS of three kinds of laccase-treated wood, the correlation between the change of ROS concentration and IB of fiberboard were measured and discussed. The optimum parameters of laccase-treated wood fibers were pH3.0, temperature 50 °C, time 2h and laccase dosages 20u/g, ROS concentration was highest in this condition; ROS concentration decreased slowly in 48h, then declined rapidly after 48h and disappeared in 7 days later. The correlation between ROS concentration and IB of fiberboard was in positive.更多还原