共查询到19条相似文献，搜索用时 281 毫秒
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水性透明涂料涂饰单板光变色的研究 总被引：2，自引：0，他引：2
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. 相似文献
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松香改性硬质聚氨酯泡沫塑料耐热性研究（Ⅱ）──泡沫组成对耐热性的影响 总被引：1，自引：0，他引：1
以化学改性松香合成了一系列具有不同组成的松香来酯型硬质聚氨酯泡沫塑料，用热重（ＴＧ）法研究了泡沫组成与耐热性的关系。研究结果表明，随ＮＣＯ／ＯＨ的增加，泡沫体起始失重温度（Ｔ＿（ｏｎ））上升，高温形变率减小。热重分析进一步证实了在此类泡沫体的两阶段热失重过程中，第二阶段热失重是山多异氰酸酯组分的热分解引起的。泡沫密度对其热重曲线无明显影响，但却与高温尺寸稳定性和强度密切相关。证明了泡沫体耐热性除受其化学结构控制外，还与泡沫孔壁厚度及强度等因素有关。 相似文献
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以化学改性松香合成了一系列具有不同组成的松蚝聚酯型硬质聚氨酯泡沫塑料，用热重法研究了泡沫组成与耐热性的关系。研究结果表明，随ＮＣＯ／ＯＨＲ的增加，泡沫体起始失重温度上升，高温形变率减小。热重分析进一步证实在此类泡沫体的两阶段热失重过程中，第二阶段热失重是由多异氰酸酯组分的热分解引起的。 相似文献
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ＴＡＮＯＵＣＨＩ自动涂装机劳爱玲（吉林省林业勘察设计院）ｌＶＲ型顶端滚筒涂料设备本机是作为预涂和修整涂抹平面的涂装机，它采用滚筒，比其它方式节省涂料，它使用氨基醇酸系列、聚氨酯系列、乳胶系列等正宗的涂料（２ｇ～１０ｇ／尺）。１．１特点１．１．１如能正... 相似文献
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歧化松香是一种广泛使用于合成橡胶生产的改性松香。由于酸价高以及其他不理想的性能,歧化松香在涂料领域中的直接使用受到阻碍。本文介绍了以缩水甘油醚为基础制备歧化松香树脂的方法,所制成的树脂可以广泛使用于制油漆、清漆、天然漆以及其它各种用途。这些酯类已制成苯乙烯改性的醇酸树脂而被进一步评价。 相似文献
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《林产化学与工业》2017,(2)
以腰果酚为原料,先合成一种分子主链结构上含有叔氨基的自催化型聚醚多元醇(CPO),然后与异多苯基多亚甲基多异氰酸酯(PAPI)在无催化剂下制备出一种腰果酚基自催化型聚氨酯泡沫(CPUF),再采用木质素对CPUF增强改性,制备腰果酚-木质素基复合自催化型聚氨酯泡沫(LCPUF),并研究了木质素添加量对此复合聚氨酯泡沫的结构与性能的影响。结果表明:采用木质素改性CPUF可有效提高泡沫的表观密度及压缩强度;当木质素添加量为CPO质量的20%时,所制备的LCPUF泡孔略有减小,表观密度和压缩强度最大,分别为81.48 kg/m~3、0.44 MPa;TG分析显示,木质素的加入对CPUF的热降解过程无显著影响。 相似文献
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以丙烯酸松香(β-丙烯酰氧基乙基)酯为主要原料制备紫外光固化涂料,通过全反射红外光谱分析(ATR FT-IR)研究了不同配方涂料紫外光照射后双键的转化率,用铅笔硬度、附着力等表征了固化过程中固化膜的力学性能。结果表明,随固化时间延长,固化膜的铅笔硬度由2H上升至3H至脱落,附着力由1级变化为2级至脱落,光引发剂浓度和紫外光强对固化初期碳碳双键转化率影响较大;当漆膜厚度由75μm变为25μm,采用薄的漆膜厚度或者Irgacure 1173光引发剂,都能加快反应速度;丙烯酸松香(β-丙烯酰氧基乙基)酯能在50 s内实现固化。 相似文献
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选取丙烯酸酯、聚氨酯、丙烯酸-聚氨酯共聚物3种水性漆为滴液,用接触角测试仪对3种水性漆在杨木表面的接触角进行测试,对比分析其对杨木表面润湿性的影响。结果表明:未进行超纯水稀释的水性漆中,丙烯酸酯、共聚物水性漆在杨木径切面的润湿性优于弦切面,聚氨酯水性漆则反之;共聚物水性漆相比于其他两种漆润湿性更好,聚氨酯次之,丙烯酸酯水性漆的润湿性则相对较差。相比未进行超纯水稀释的水性漆,经稀释处理的3种水性漆在杨木表面的接触角均有不同程度的下降。接触角下降率分析表明:丙烯酸酯水性漆相比其他两种漆在杨木表面的润湿性更好,此外共聚物水性漆在杨木弦切面润湿性优于径切面,而其他两种水性漆则相反。 相似文献
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将亲水改性的多异氰酸酯分别与马来海松酸改性聚酯多元醇(MPP)、聚酯多元醇(PP)和Bayhydrol D270聚酯多元醇水分散体进行复合交联制得MPP-2K-WPU、PP-2K-WPU和D270-2K-WPU,并采用FT-IR和DSC对产物进行表征。利用接触角法研究了n(—NCO)∶n(—OH)及多元醇组分种类对2K-WPU涂膜接触角、表面能和耐水性的影响,并采用Equation of State法和Owens-Wendt-Rabel-Kaelble法对试验数据进行分析。结果表明,与甲酰胺系列(甲酰胺、甲酰胺-二碘甲烷)检测液体相比,水系列(水、水-二碘甲烷)检测液体能更好地对2K-WPU涂膜表面性能进行描述;随着n(—NCO)∶n(—OH)的增加,MPP-2K-WPU的表面能先减小后增大,耐水性呈现先增强后减弱的趋势,当n(—NCO)∶n(—OH)为1.5∶1时其表面能最小、耐水性最强;与2种对照样(PP-2KWPU和D270-2K-WPU)相比,MPP-2K-WPU的表面能最小且耐水性最强。 相似文献
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马来松香合成耐热绝缘漆的研究 总被引：2，自引：0，他引：2
以马来松香为原料合成了多元醇,并用氨基树脂交联,制备了耐热经缘漆－氨基经缘烘漆,讨论了不同多元醇,不同氨基树脂和固化条件等因素对漆膜性能的影响。研究结果表明,该漆可作为Ｂ级绝缘漆使用。 相似文献
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W. P. Smeljanez 《Journal of pest science》1978,51(3):34-37
A new classification of resistance of plants to phytophagous insects is presented basing on the fundamental relationships between the plant and the pest. Two kinds of resistance are distinguished, namely an active (antibiosis) and a passive one. The last can be divided into the ecologic resistance and the tolerance. All the three kinds of resistance are subdivided into a horizontal type (variability of resistance in different plant species or sort) and a vertical type (variability of resistance in one plant species) respectively. Each of these two, types again consists on three forms corresponding with the resistance to a certain pest or with a group of pest species or with a whole complex of pests resp. diseases. By marking the types mentioned with the initial letter one can characterize each form of resistance by help of a formula. 相似文献
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利用天然可再生资源没食子酸(GA)与氢化萜烯基环氧树脂(HTME)在一定条件下反应制备了环氧树脂基多元醇(HTME - GA多元醇).通过研究合成反应的影响因素,确定了HTME - GA多元醇的合成反应条件:以GA物质的量12.5倍的正丙醇为反应溶剂,以占HTME与GA总质量2%的季铵盐为催化剂,HTME与GA共沸回流反应3h.经FT - IR、NMR光谱表征了HTME - GA多元醇的化学结构,比较了该多元醇与聚己二异氰酸酯HN90T、改性聚己二异氰酸酯EC385的交联反应特性及交联产物性能.实验结果表明,HTME - GA多元醇与EC385的交联产物具有优良的机械力学性能,与HN90T的交联产物具有较好的耐液体介质性能和硬度,但后者柔韧性较差.随着NCO与OH物质的量比的增大,交联产物的硬度和耐液体介质性能提高. 相似文献
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We investigated the curing behavior of an emulsion polymer isocyanate adhesive for wood with different ethylene-vinyl acetate
(EVA) emulsions, because it was found that the ethylene/vinyl acetate weight composition (E/VA ratio) of EVA could control
the volume of gas emitted from the adhesive. EVA with higher VA content reduced the volume of gas emitted at the initial stage,
which was caused by the extent of the reaction between the NCO groups and water. The reaction scheme of NCO could not be determined
because the broad infrared (IR) absorptions due to CaCO3 and water masked the information of the NCO products in IR spectra.
Examination of the degree of swelling suggested that the adhesive films stored for 3 weeks had the same degree of cross-linking
structure in spite of the variation of EVA. This result was supported by IR spectroscopy, which showed the same amounts of
NCO remained in these films. All the adhesives prepared in this study had satisfactory bond performance. The findings indicate
that the E/VA ratio affects the curing behavior of the adhesive in the initial curing stage, whereas the cross-linking structure
and the bond performance were independent of the E/VA ratio after storage for 3 weeks.
Part of this report was presented at Wood Adhesives 2005, November 2–4 2005, San Diego, CA, USA 相似文献
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《Wood material science & engineering》2013,8(3):188-197
Abstract Joints are generally the weakest part of furniture and they are primary cause of failure. To ensure durability and performance of furniture, it is important for a designer to understand the stresses acting on the joints for preparing suitable design and specification of a furniture. Since each type of joint is unique in construction, it is important to know their strength, when subjected to various stresses namely shear, bending, and tensile, by testing the joints. Since there is no established test method for joints, this study was carried out to categorize joints based on their shape, identify the stresses acting over them and develop test methods for testing furniture joints in three modes namely shear, bending, and tension, which are required for designing joints of any furniture and also provide means of comparing strength of different types of joints. Different types of furniture joints were taken for the study and were classified based on their shapes such as L-shaped, T-shaped, straight, and corner joints. Six types of jigs (one type for bending, two types for shear, and three types for tension) were designed and developed for testing the joints, in such a way that any type of joint can be tested in three modes, i.e., bending, shear, and tension using a universal testing machine. The criteria for section of jigs for performing tests on joints, based on their shape and stresses acting on a particular joint, were reported. Tests were carried out using all the six type of jigs to check the suitability of jigs and test methods developed in the study. 相似文献
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Iis Yuningsih Istie Sekartining Rahayu Dumasari Lumongga 《Wood material science & engineering》2020,15(4):229-236
ABSTRACT The quality of finished wood products depends on the quality of its coating layer. An important indicator for evaluating the quality is Adherence of the paint on the wood surface. The purpose of this research was to analyze the effect of wood surface roughness and the viscosity of acrylic paints (pure acrylic and acrylic copolymer) to the wettability and Adherence for long and short rotation teaks. Wood surface with various degrees of roughness was prepared by sanding with abrasive papers of P120, P240, and P360 grits. Different viscosity of the acrylic paints was prepared composition between paint and water (w/w) of 100:0, 90:10, 80:20, and 70:30. The wettability of the acrylic paints on teak wood surfaces was measured using a sessile drop contact angle method with the S/G model. Adherence of the coating layer was measured using a crosscut test. The results showed that the increase in the roughness (Ra) and the decrease in the viscosity of the paints resulted in the increase in the wettability which leads to better Adherence of acrylic paints on the surface of teak woods. The pure acrylic paint generated better wettability and Adherence compared to the acrylic copolymer. 相似文献