丙烯酸-2-羟基乙基酯/丙烯酸松香衍生物紫外光固化涂料的性能研究

采用红外光谱(FT-IR)、热重分析(TGA)和接触角分析了丙烯酸改性松香(β-丙烯酰氧基乙基)酯(ARA)/丙烯酸-2-羟基乙基酯(HEA)紫外光固化涂料的耐热性能和基材浸润性能,考察了HEA用量对涂层的凝胶含量、附着力和铅笔硬度的影响。研究结果表明:随着HEA含量的增加,对基材的附着力增强,铅笔硬度逐步降低。当含HEA20%时,涂料具有最佳的附着力(1级)、铅笔硬度(2H)、凝胶含量和热稳定性。     

抽提物对高温热处理材光降解进程的影响

将经3种不同抽提处理的高温热处理欧洲赤松(Pinus sylvestris L.)和山毛榉(Fagus longipetiolata Seem.)木材及其对照材置于氙灯老化箱中加速老化1 008 h,测定老化过程中表面颜色的变化,并使用扫描电镜(SEM)、傅里叶红外光谱(FT-IR)和X射线光电子能谱(XPS)分析老化前后木材表面宏观和微观结构的变化,旨在探究不同抽提物对高温热处理材的光降解进程的影响。结果表明:1)高温热处理材中抽提物的存在有利于缓解其光老化进程,提高热处理材的颜色稳定性;2)碱抽提物对热处理山毛榉表面材色的影响最为显著,其存在有利于延缓老化过程中热处理材表面颜色的变化,苯醇及冷水抽提出的极性抽提物对热处理材的颜色稳定性具有积极作用,冷水抽提后的热处理山毛榉在老化过程中出现射线细胞剥离现象;3)在老化过程中,热处理欧洲赤松的表面颜色变化相对山毛榉大,这是因为热处理欧洲赤松的材色较山毛榉浅,碱抽提物对热处理欧洲赤松颜色稳定性的影响相对较小,而苯醇抽提物及冷水抽出物可提高其耐老化性。     

锯材种类与切面对UV喷绘涂层性能的影响

近年来,高效环保的UV数码喷绘技术已逐渐应用于家具板材的表面装饰。研究木质基材对于喷绘性能与效果的影响将为基材的选择与改性提供理论支持。选取3种代表性实木锯材:樟子松、桦木、白蜡木,分析其解剖结构与表面特性,包括基材的表面粗糙度、表面湿润性、SEM形貌及BET比表面积、孔径等对UV喷绘涂层的光泽度、附着力、耐磨性的影响;表征涂层与基材结合界面的形貌与化学结构,探索界面结合机制。结果表明:樟子松管胞与介孔含量高,导致横切面粗糙度最大,喷绘涂层光泽度差;桦木本身颜色暗淡、明度低,导致涂层颜色偏暗;白蜡木横切面的湿润性较好,喷绘后涂层附着力高达1级;同时各锯材横切面由于管胞、导管的影响导致喷绘涂层显现出生长轮的形状;界面分析结果证实,油墨并没有与木材发生化学反应,喷绘图案与木材的界面结合是以范德华力为主的机械锚钉结构。因此,对实木材料进行UV喷绘时,应选择材色较浅、明度较高的基材,如需打印涂层遮盖木材纹理,则应同时考虑选择孔含量较少、较小且分布均匀的基材。     

刨花板表面粉末涂饰初探

采用砂光、涂白胶和涂导电漆等不同表面处理方式处理刨花板基材,综合考虑上粉量及涂膜性能,获得刨花板基材表面处理的较佳方法.试验表明,刨花板表面处理较佳方式是涂导电漆,其次是砂光处理,最后是涂白胶.涂导电漆处理的刨花板基材,粉末涂饰的固化条件为160 ℃下烘干10 min.固化后的粉末涂层性能为:涂膜附着力1级,硬度4H,具有较好的耐水性.     

紫外光固化油漆涂层结构对漆膜性能的影响

为优化番龙眼实木地板基材的紫外光固化油漆涂布工艺,研究了由3种油漆构成的6种涂层结构对漆膜柔韧性、附着力、硬度及耐磨性等的影响。结果表明:涂层结构对漆膜的柔韧性、附着力、硬度和耐磨性均有明显影响,底层漆对附着力有较大影响,面层漆明显影响漆膜的硬度和耐磨性。在生产中可采用弹性漆靠近基材、加硬漆处于中间、耐磨漆靠近面层的优化涂层结构。     

紫外光固化漆酚铈聚合物涂层的制备与 性能研究

以稀土化合物氯化铈和漆酚为原料,在无引发剂的条件下利用紫外光(UV)辐照法制备漆酚铈聚合物涂层。采用X射线衍射(XRD)、傅里叶变换红外光谱(FT-IR)、扫描电镜(SEM)、热重分析(TG)等测试方法对涂层的结构和热稳定性进行了表征。考察了氯化铈用量对涂层的物理机械性能和耐化学介质性能的影响,并对制备的漆酚铈涂层进行电化学阻抗测试(EIS),结果表明:在UV辐照条件下,漆酚羟基与铈离子发生配位作用,同时侧链不饱和键发生交联聚合反应从而固化;掺杂氯化铈可显著改善天然生漆(RL)固化膜的热稳定性和耐碱性;随着氯化铈掺杂量的增加,涂层的附着力、硬度、耐腐蚀性能呈先上升后下降的趋势。氯化铈用量为18%的漆酚铈聚合物复合涂层的硬度和附着力分别达到6H和1级,且其耐腐蚀性能最佳。     

有机硅涂层对户外用竹材耐老化性能的影响北大核心

为提高户外用竹材的耐老化性能及使用寿命,研究以甲基苯基有机硅氧烷树脂、脂肪族聚氨酯丙烯酸酯和3-氨丙基三乙氧基硅烷为原料,制备竹材用耐老化涂层,并分别对有自制涂层的试样和空白试样进行1080 h的人工加速紫外老化试验。结果表明:有涂层试样经过1080 h老化后,依然保持最高级0级的附着力,色差值ΔE仅为4.32,失光率为6.3%,涂层外观保持良好。红外谱图显示老化后涂层的化学成分几乎未变。有机硅涂层可以有效提升户外竹材的耐老化性能和使用寿命。     

慈竹竹原纤维与黄麻纤维红外及二维相关光谱分析

以慈竹竹原纤维和黄麻纤维为对象,采用红外光谱法和二维相关红外光谱分析技术,对2种纤维及其化学处理后的单根纤维进行研究。结果表明:慈竹竹原纤维和黄麻纤维的一维红外光谱主要区别于1736cm-1处的CO伸缩振动和木质素苯环特征吸收峰;二者经双氧水-冰醋酸处理后,黄麻单根纤维在1736cm-1附近仍存在明显的吸收峰。在高分辨的二维同步相关谱中,慈竹竹原纤维和黄麻纤维特征差异更为明显,慈竹竹原纤维在1000～1250cm-1范围内有8个自动峰,1008cm-1处强度最大;黄麻纤维有7个自动峰,1217cm-1处强度最大;同时在1435～1750cm-1范围内,黄麻纤维在1726cm-1(C=O伸缩振动)处出现较强的自动峰,而慈竹竹原纤维光谱中没有。各区域内自动峰均为正相关。与化学处理前纤维谱图相比,二者单根纤维的二维相关红外光谱发生了改变,表明纤维成分对其热微扰过程中的变化有一定影响。初步研究表明:二维相关红外光谱为竹原纤维的识别提供了更为丰富的信息,可作为竹原纤维识别的一种新方法。     

高温煅烧纤维素纳米晶体对水性木器涂膜耐霉性能的影响

研究了高温煅烧前后纤维素纳米晶体(CNC)添加量对水性涂膜硬度、附着力、抗冲击强度、色差及对水性涂膜耐霉性能的影响。结果表明:加入CNC与高温煅烧后CNC的水性涂膜硬度均能提高,加入CNC的水性涂膜比加入高温煅烧后CNC的水性涂膜硬度高;CNC与高温煅烧后CNC对水性涂膜的附着力和抗冲击力影响不大;CNC对水性涂膜的色差影响最大值为8.4,高温煅烧后CNC对水性涂膜的色差影响最大值为5.7,比高温煅烧前的涂膜色差最大值小2.7,颜色更加均匀;水性木器涂膜中加入高浓度CNC比加入低浓度CNC有更好的耐霉效果,加入高温煅烧后的CNC对木霉有更好的抑制作用。     

废弃牛奶盒/聚乙烯复合材料耐老化性能的研究

对放置在阳光曝晒环境、户外自然干湿环境和氙灯耐气候老化箱三种环境中进行老化实验的废弃牛奶盒/聚乙烯复合材料的颜色变化和抗弯性能进行了研究,结果表明:①材料在三种环境下都发生了褪色,影响了材料的美感和顾客的喜好程度;②氙灯耐气候老化箱对材料的颜色变化影响最大,其次是阳光曝晒环境,最后是户外自然干湿环境;③在阳光曝晒环境和户外环境中放置6个月后,材料的弹性模量和抗弯强度均呈现出先下降后又上升的趋势,而在氙灯环境中放置1500h后,其弹性模量和抗弯强度明显下降.     

涂覆工艺对杉木表面可逆变色水性涂料性能的影响

探究涂覆工艺对杉木表面可逆变色水性涂料性能的影响。以底漆道数、面漆道数与变色油墨添加方式为试验因素,进行三因素两水平正交试验并优化工艺参数,探究不同涂覆工艺对添加变色油墨水性涂料漆膜的力学、光学、耐液性能的影响,研究老化温度和时间对漆膜变色性能的影响。结果表明:变色油墨添加方式对漆膜色差和光泽度影响最大;对于添加变色油墨的水性涂料,涂覆工艺对漆膜附着力、抗冲击力、耐液等级等原有性能影响较小,不同涂覆工艺下漆膜光泽度变化无明显规律;当涂覆工艺为3道底漆、3道面漆、变色油墨添加于面漆中时,形成的漆膜变色性能、光泽度较佳,漆膜综合性能良好,漆膜变色性能在老化时间和温度变化的情况下保持稳定。该研究为智能涂料的发展提供新思路。     

Analysis of sanding parameters on surface properties and coating performance of red oak wood

Sanding is the most common machining process used to prepare wood surfaces prior to coating. Hence, to improve surface quality and coating performance during this process, an optimal set of machining parameters should be established according to wood species and its final use. The effects of grit size and feed speed on surface properties and coating performance of red oak wood were studied. Surface quality was assessed by surface roughness, scanning electron micrographs, and wetting analyses. Coating performance was evaluated using pull-off adhesion tests on coated surfaces before and after an accelerated weathering. The results showed that smoother surfaces are obtained as the grit size number of the abrasive increased. On the other hand, minor differences were observed on cell damages and surface roughness as feed speed changed. Also, there was little difference among treatments concerning wetting behavior and surface energy. Pull-off strength was more affected by changes in grit size than feed speed. A P100-grit size program with a feed speed of 7 m/min resulted in a suitable roughness which provided good adhesion and high pull-off strength after aging test.     

Study on the changes in surface characteristics of <Emphasis Type="Italic">Populus tomentosa</Emphasis> due to thermo-hydro-process

The effects of high temperature, moisture, and mechanical action during the thermo-hydro-mechanical (THM) processing, on the changes in surface properties of poplar, namely, surface color, roughness, wettability, and microstructure, were investigated in this study. The correlation between observed changes in surface properties and chemical characteristics was also analyzed. Poplar woods with high moisture content were compressed using different pressures at temperature of 160 °C for four different periods. The wood surfaces became darker and smoother, and their surface free energy decreased significantly after the THM process. THM process markedly reduced surface hygroscopicity compared to the control wood. The cell lumens of THM wood became narrow with increasing compression ratio due to the enhancing high pressure. Collapse and fractures of cell walls developed during THM treatment. Furthermore, results indicated that a series of chemical reactions in different components of wood took place during THM process, such as degradation of hemicelluloses, condensation of lignin, and decomposition of extractives. In turn, these chemical modifications contributed to the darkening of color as well as the reduction of wettability and surface free energy of THM wood.     

高温热处理对水曲柳材色的影响

The color change of ash wood ( Fraxinus mandshurica ) before and after high temperature heat treatment were investigated with WSC-S color difference meter in this paper. The results showed that: the color of treated wood is affected by the processing temperature, the higher the temperature, the darker the appearance, moreover, the change in L~* component can be used for quantitative analysis on color change. The color of treated ash wood by suitable processing temperature could be simulated to some valuable wood, for example, teak wood, some rosewood species, etc. The color of treated wood could be well replicated from laboratory scale experiments to commercial scale production.     

Superheated steam treatment of rubberwood to enhance its mechanical,physiochemical, and biological properties

ABSTRACT

This research was aimed to investigate mechanical properties, color and cell-wall components changes, and durability of pre-dried rubberwood (Hevea brasiliensis) after superheated steam (SS) treatment. Wood samples were treated at different SS temperatures (140–180°C) for 1–3?h. The highest compression strength parallel-to-grain, hardness and impact strength were found for samples treated at 160°C for 3?h (30.7% higher than untreated), at 150°C for 1?h (26.6% higher than untreated) and at 150°C for 2?h (52.6% higher than untreated), respectively. The surface color became darker after each treatment in comparison with the untreated wood. The number of accessible hydroxyl groups decreased and the relative cellulose crystallinity increased with SS temperature, indicating decreased hygroscopicity of the treated wood. Also, SEM micrographs of wood surface showed consistent decrease in starch particles with treatment temperature. Both decay and termite resistances of treated rubberwood improved with treatment temperature. All the analyzes showed that dried rubberwood treated with SS had some improvements in the mechanical properties, decreased hygroscopicity, and increase resistance to decay.     

炭化木物理力学性能的研究

以速生杉木为原料制备炭化木,主要研究了炭化工艺条件对炭化木(又称热处理木)物理力学性能的影响。研究表明:当热处理温度由常温增加至220℃时,炭化木材色逐渐变深,含水率逐渐降低,由13.40%降至4.89%,吸水性能较大幅度降低,由未处理素材的1.616%降至0.879%,同时密度由未处理素材的0.368g/cm~3减小至0.326 g/cm~3,静曲强度下降约25%左右,弹性模量先增加后减小,减小量约4%左右,冲击韧性也先增加后减小,减小量约42%左右,受热处理条件影响程度较大,而且木材干缩和湿胀系数明显下降,较大程度提高了木材的尺寸稳定性。     

蒸汽介质热处理对毛白杨木材颜色的影响

以毛白杨木材为研究对象,采用蒸汽介质热处理方法在氧气含量低于2%的密闭容器中以温度170～230℃、时间1～5h的处理条件对其进行热处理。结果表明:随着处理温度的升高和处理时间的延长,色饱和度差ΔC*逐渐减小、色差ΔE*和色相差ΔH*逐渐增大,说明热处理后木材的颜色由原色逐步过渡到深褐色。方差分析和多重比较结果表明:热处理温度比热处理时间对毛白杨木材颜色变化的影响更为重要。此外,进一步得出了色差值与热处理温度、时间三者之间的回归模型。利用此特性,对一些浅色木材进行热处理,可赋予其凝重的颜色,同时还可增强其尺寸稳定性,从而提高其产品附加值,扩大应用领域。     

Weathering durability of CCB-impregnated wood for clear varnish coatings

Outdoor performances of a polyurethane varnish and an alkyd-based synthetic varnish coated over chromium-copper-boron (CCB)-impregnated Scots pine (Pinus sylvestris L.) and chestnut (Castanea sativa Mill.) [10 (R) × 100 (T) × 150 (L) mm] were investigated. These varnishes were also applied to the wood surface as sole coatings or impregnated into wood as water-repellent (WR) solutions. Outdoor exposure was performed in the Black Sea region of northern Turkey (41°N, 39.43°E) where humid weather predominates throughout the year and accelerates decomposition of coated wood surfaces. The wood panels were exposed at 45° south on their tangential surfaces. After 9 months of exposure to summer, autumn, and the following winter season, the color and glossiness changes of the exposed surface, adhesion of the coating layer to the wood surface, water absorption through the coating layers, mass loss, and the hardness of the board surface were studied. CCB impregnation greatly stabilized the surface color of varnish-coated panels of both wood species. Gradual decreases of adhesion between varnished layers and preimpregnated surfaces were attributed to probable weakening of interactions at the interface of the treated wood and the film layer. A superficial cleaning process of treated wood is suggested to improve glossiness and adhesion. The coated wood surface became harder with time on outdoor exposure until a maximum hardness occurred followed by softening, whereas the uncoated surface softened steadily. Polyurethane varnish yielded a harder surface than synthetic varnish. Mass losses of wood panels after 9 months of exposure were negligible for all treatments compared with the untreated controls, which were totally discolored and eroded on the surface. It is concluded that long-term exterior wood protection has been achieved by a successful combination of an appropriate preservative treatment followed by a compatible surface-coating process.     

观光木木材涂饰工艺研究

观光木是广西大力发展的珍稀树种之一,具有优良的材性和机械加工性能.本文以观光木木材用的涂饰聚氨酯清漆和水性木器漆为研究对象,研究漆膜理化性能、光泽度和色度学特征的变化规律,为观光木木材高附加值实木制品的开发利用提供理论依据和信息.研究表明：①聚氨酯清漆的最佳涂饰工艺为：砂纸选用400#（表面粗糙度Ra为2.3）,底漆涂布量为50 g/m2,面漆涂布量为70 g/m2,涂饰次数为3底3面;②水性木器漆涂料的最佳涂饰工艺为：砂纸选用320#（表面粗糙度Ra为2.9）,底漆涂布量为100g/m2,面漆涂布量为120g/m2,涂饰次数为3底3面;③从漆膜理化性能、改善观光木表面光泽度和色度学特征以及节约原料看,聚氨酯清漆比水性木器漆有较明显的优势.     

Effect of accelerated aging on some physical and mechanical properties of bamboo

The objective of this study was to investigate the effect of accelerated aging on compression strength, modulus of rupture, modulus of elasticity, color change, volumetric swelling, and volumetric shrinkage of bamboo specimens with and without node sections. In the study, these properties were compared with those of Scots pine and beech wood specimens. Depending on bamboo sections, the aging procedure reduced modulus of rupture, modulus of elasticity, and compression strength. Bamboo specimens showed relatively high strength properties compared to wood specimens due to having high density. Strength properties increased from bottom to top of bamboo culms. The presence of nodes in the specimens reduced compression strength and modulus of rupture but affected modulus of elasticity slightly. Remarkable color changes in specimens were observed after aging. Volumetric swelling and shrinkage of bamboo specimens exposed to aging decreased probably due to heat effect of aging procedure.