杨木单板及其染色后的光变色研究

以杨木单板及其染色单板为试材,使用氙光衰减仪进行辐射试验,分析这两种单板的光变色规律及影响因素,并进行耐光性能评价。结果表明:杨木单板的光变色是木材本身;染色杨木单板的光变色是染料和木材共同作用的结果,影响其光变色的主要因素是染料的品种和结构。因此,杨木单板的光变色小于染色杨木单板,而染色杨木单板中酸性蓝染色单板光变色最显著。     

以光谱反射曲线评估染色单板的耐光性

以杨木和桦木单板为试材,引入光谱反射曲线研究了室内自然光环境下染色单板的光变色过程,分析了树种、漂白处理、染料种类及浓度对染色单板耐光性的影响。结果表明,光辐射后染色单板K/S曲线呈下降趋势,光谱反射率曲线向黄光方向移动,染色单板发生黄化。漂白处理加速了染色单板的光变色。染料品种对染色单板耐光性影响显著,酸性蓝染色单板的光谱反射率曲线变化明显,而酸性大红的变化不大。利用光谱反射曲线可快速直观地评估染色单板耐光性的优劣。     

温致变色杨木单板浸渍工艺

以杨木单板为基体,以热敏染料、显色剂、十四醇、增感剂为木材温致变色剂,利用超声波浸渍注入木材的方法制备可逆温致变色杨木单板,研究可逆温致变色杨木单板的浸渍工艺。结果表明:影响试件变色色差(ΔE*)的主要试验因子为超声波功率,方差分析其在0.01水平下对试件ΔE*影响显著;其次为浸渍时间和浸渍温度,方差分析二者在0.01水平下对试件ΔE*影响不显著。最佳浸渍工艺为浸渍温度75.0℃、浸渍时间4.0h、超声波功率120.0W。研制成可逆温致变色杨木单板新产品,杨木单板起始变色温度为26℃,终止变色温度为32℃;温度由26℃升至32℃时,试件由蓝色变成木材本色;温度由32℃降至26℃时,试件由木材本色变成蓝色,达到室温可逆变色的效果。     

I-214杨染色单板光变色规律的研究

以染料弱酸深蓝5R和活性艳红X-3B染色的I-214杨素材和漂白板为试材,选用氙光作照射光源,考察不同染料、不同工艺条件下染色单板在110 h光照过程中试材表面材色指数,即明度指数(L*),色度指数(a*与b*)和变色度(△E* ab)的变化.结果表明:染色单板在110 h氙光照射过程中变色明显,b*值提高显著;△E* ab在光照初期大,后期平缓直到不变;同一品种染料,高浓度染液中染色单板比低浓度染液的光照变色大,浸染时间长短对染色单板光照变色影响不明显,先漂白再染色的单板材色均匀,光照变色平缓;不同品种染料的染色单板光照变色规律有差异.     

6种阔叶树材红外光谱特征的比较

采用红外光谱(FT-IR)法对6种阔叶树材进行研究,通过对共有吸收峰、特征峰、相对吸收强度和二阶导数谱进行比较分析,得出了6种阔叶树材的具体差异。试验结果表明:6种阔叶树材的红外图谱共性特征较为明显,1 000～4 000 cm-1范围内的14个吸收峰中有12个吸收峰为共有峰;其中最强峰分别为1 033～1 052 cm-1范围内的C—O伸缩振动吸收峰和3 394～3 412 cm-1范围内的羟基特征峰。6种阔叶树材的FT-IR图谱、相对吸收强度和二阶导数谱均有不同程度的差异:在1 110～1 122 cm-1范围内只有楠木出现较小吸收峰;楠木和杜仲在1 237～1 264 cm-1范围内形成较宽吸收峰; 1 624～1 657 cm-1范围内,杜仲、花榈木、凹叶厚朴这3种木材具有一定的差异;而枫香和喜树在1 559～1 648 cm-1范围内明显区别于其他4个树种。相对吸收强度的比较结果为A3 402/A1 510和A1 661/A1 510处的2个峰位的差别较大;在1 000～1 800 cm-1区域内,6个树种的红外光谱的二阶导数谱在从峰形、吸收峰的位置、形状以及出峰数量上存在显著差异。通过对6种常见阔叶树材红外光谱特征的比较和分析,可为木材的快速鉴定和分类提供理论依据。     

基于FT-IR的木质碳纤维原丝固化增强机理的研究

以甲醛为固化剂,盐酸为催化剂,固化处理木材液化物初纺纤维后得到木质碳纤维原丝.利用FT-IR考察了盐酸浓度、固化时间、升温速率对固化后木质碳纤维原丝化学结构变化的影响,并分析了原丝的固化增强机理.结果表明:随盐酸浓度和固化时间的增加,原丝1610～1510、1455、900～650 cm-1处吸收峰强度都逐渐降低；随升温速率的增加,原丝3423、2925 cm-1处吸收峰逐渐减弱,1610～1510、1454 cm-1处吸收峰强度先减弱后增强,1101、900～650 cm-1处吸收峰强度却明显增加.固化过程中原丝结构上的芳环与固化液中的+CH2OH离子发生的交联反应,以及酚羟基之间、酚羟基与固化液中+CH2OH离子之间发生的脱水缩合反应,促使了原丝内部网状交联结构的形成,提高了原丝的强度.     

活性染料对杨木单板染色耐光性影响的研究

采用活性染料、酸性染料和直接染料分别对杨木单板进行染色,分析并确定耐光性最佳的染料及此染料染色的最佳工艺参数。结果表明：活性染料染色杨木单板的耐光性最佳;确定出的最佳染色工艺参数为：染料浓度10g/L,染色时间2．5h,染色温度60℃,浴比20：1。这一研究结果为杨木单板仿制珍贵木材提供了理论依据和实际生产工艺参数。     

纳米TiO_2改性涂料涂饰染色单板的光变色

利用纳米TiO2改性水性双组份聚氨脂清漆和丙烯酸清漆,将改性涂料直接涂饰染色单板并进行氙光辐射试验,探讨了纳米TiO2对染色单板光变色的抑制作用以及纳米TiO2加入量对光变色性的影响。结果表明,聚氨酯和丙烯酸清漆中纳米TiO2加入量分别为3%和5%时对染色单板光变色的抑制效果最佳。光辐射前后,涂饰改性与未改性聚氨酯清漆杨木染色单板的色差ΔEa*b分别为18.75、22.98,丙烯酸清漆的分别为11.75和16.98。改性涂料涂饰染色单板的光变色度小于未改性涂料染色单板,主要在于改性涂料能显著抑制染色单板红绿色品指数a*的变化。     

水性透明涂料涂饰单板光变色的研究

以涂饰与未涂饰的杨木和樟子松单板为试材,利用氙光衰减仪进行光辐射试验,分析其光变色规律及影响因子,并进行耐光性能评价.结果表明:涂饰与未涂饰的单板受光辐射易发生变色,主要表现为明度指数L*降低,色度指数a*和b*上升,其中涂饰与未涂饰的樟子松单板的色度指数b*变化明显;涂饰水性双组分聚氨酯清漆单板的总色差值明显大于涂饰水性丙烯酸清漆单板,涂饰樟子松单板的总色差值大于涂饰的杨木单板;涂料种类和单板树种对涂饰单板的光变色均有一定的影响,但涂料种类影响较明显;涂饰与未涂饰水性双组分聚氨酯清漆的单板总色差值差异不明显,涂饰水性丙烯酸清漆单板的总色差值小于未涂饰的单板.     

等离子体处理对杨木单板层积材性能的影响

采用常压冷等离子体处理杨木单板制备非结构用单板层积材(LVL),研究处理功率、处理速率对单板层积材性能的影响。结果表明:常压冷等离子体处理能明显改善杨木LVL的胶合性能,当处理功率为4.5 k W、处理速率为2 m/min时LVL的浸渍剥离率降低了59.3%;常压冷等离子体改性可以明显影响杨木单板表面的物理化学性质,提高单板表面润湿性,当处理功率为6 k W、处理速率为8 m/min时脲醛树脂胶在杨木单板表面接触角的初始角下降25.4%、平衡角下降36.8%;红外光谱分析表明,杨木单板经常压冷等离子体处理后表面羰基数量有所增加,并产生少量的酮基,杨木表面的共轭羰基或羧基数量增加,C—O数量也有所增加。     

Dyeability of Chemically Treated Wood and its Discoloration by UV-ray Irradiation

INTRODUCTION Wood is far from a stable material. One of the biggest challenges for woodworking is learning to work within the constraints of wood properties. Discoloration of wood directly influences the decorative performance of wood products. Therefore, the degree of color change is a critical factor that determines the utilization area of dyed wood (Sakuragawa Satoshi, 1996). Discoloration has occurred because the wood components and dye molecules are degraded by UV-ray (Kaneko Shin…     

Investigation of Carbohydrate Compositions for Poplar I-214 and Chinese Fir

Carbohydrates are main compositions for wood (Menachem et al. 1991). The chemical components of poplar I-214 and Chinese fir have been reported (Huang Luohua et al. 2002; Qin Tefu et al. 2003). Through the studies of carbohydrate compositions of poplar I-214 and Chinese fir, different composition of monosaccharides can be found in both poplar I-214 and Chinese fir. 1 MATERIALS AND METHODS 1.1 Materials Wood samples of Chinese fir (Cunninghamia lancedata) and poplar I-214 (Populus…     

Natural Resistance of Two Plantation Woods Populus × canadensis cv. and Cunninghamia lanceolata to Decay Fungi and Termites

Natural durability of two plantation woods, Chinese fir and I-214 poplar, was investigated thoroughly by three testing methods, namely an accelerated laboratory decay test, a fungus cellar test and a field test. Aft er the decay test using Postia placenta and Trametes versicolor, Chinese fir and the I-214 poplar showed 34% and 69% of mass loss, respectively, indicating they should be classified as slightly durable and non-durable wood. This conclusion was confirmed by the fungus cellar test and the field test. Like the performance in the decay test, I-214 poplar showed no resistance to termites either in the laboratory or in the field,whereas Chinese fir would be classified as moderately resistant.     

微纳纤丝改性豆胶制造染色杨木胶合板

将不同微纳纤丝添加量的三聚氰胺树脂涂饰在杨木单板表面,并以添加微纳纤丝的豆胶作为胶黏剂,制造杨木胶合板,检测微纳纤丝添加量对染色杨木单板表面色牢度、胶合板表面耐磨性能、胶合强度的影响。结果表明:微纳纤丝可明显改善单板表面色牢度及表面耐磨性能;在豆胶中加入微纳纤丝,可提高胶合板的胶合强度。     

Natural Resistance of Two Plantation Woods Populus × canadensis cv. and Cunninghamia lanceolata to Decay Fungi and Termites

Natural durability of two plantation woods, Chinese fir and I-214 poplar, was investigated thoroughly by three test- ing methods, namely an accelerated laboratory decay test, a fungus cellar test and a field test. After the decay test using Postia pla- centa and Trametes versicolor, Chinese fir and the I-214 poplar showed 34% and 69% of mass loss, respectively, indicating they should be classified as slightly durable and non-durable wood. This conclusion was confirmed by the fungus cellar test and the field test. Like the performance in the decay test, I-214 poplar showed no resistance to termites either in the laboratory or in the field, whereas Chinese fir would be classified as moderately resistant.     

Fluctuation of temperature inside poplar stems in relation to air temperature

Two Euramerican poplar clones, ‘I-214’and ‘I-45/51′, were badly damaged by frost cracks in 1981 and 1985. Thermocouples attached to 12 trees showed that clone ‘I-45/51’was more resistant to winter and late frosts, possibly due to its significantly thicker and rougher bark in comparison to ‘I-214′.     

Natural Resistance of Two Plantation Woods Populus × canadensis cv. and Cunninghamia lanceolata to Decay Fungi and Termites

Natural durability of two plantation woods, Chinese fir and I-214 poplar, was investigated thoroughly by three testing methods, namely an accelerated laboratory decay test, a fungus cellar test and a field test. After the decay test using Postia placenta and Trametes versicolor, Chinese fir and the I-214 poplar showed 34% and 69% of mass loss, respectively, indicating they should be classified as slightly durable and non-durable wood. This conclusion was confirmed by the fungus cellar test and the field test. Like the performance in the decay test, I-214 poplar showed no resistance to termites either in the laboratory or in the field, whereas Chinese fir would be classified as moderately resistant. [Supported by Sino-Japanese Technical Cooperation Project Titled “Studies on Chinese Plantation Wood” (JICA PROJECT/033-1418-E-O)]