复合阻燃剂对杨木胶合板性能的影响

研究以硼酸、磷酸、氯化铵和锰化物为主要成分制备多元素复合阻燃剂,用浸渍法处理杨木单板并压制成胶合板,检测胶合板各项性能。结果表明:该阻燃剂对胶合板的阻燃性能有积极影响,其中热释放速率(HRR)降低26.32%,总释放热(THR)降低90.04%,总烟释放量(TSR)降低68.40%,同时胶合板的甲醛释放量降低了14.82%,说明该阻燃剂不仅有良好的阻燃效果和抑烟效果,还具有一定的甲醛捕捉能力。该阻燃剂对胶合板力学性能有一定的负面影响,板材胶合强度、弹性模量、静曲强度均有一定程度降低,但仍能达到GB/T 9846-2015《普通胶合板》标准要求。     

橡胶木胶合板阻燃技术研究Ⅲ.橡胶木阻燃胶合板的吸潮性

采用在相对湿度为１００％的环境中,测定材料因吸潮而增重的方法对６种橡胶木阻燃胶合板吸潮率、药剂吸潮率以及胶合板吸药率为１５％时与未阻燃处理的橡胶木胶合板吸潮率进行了对比和评估。其中磷氮系阻燃剂的吸潮性明显高于ＷＦＲ树脂型阻燃剂。所有阻燃处理的橡胶木胶合板吸潮性均高于未处理的普通橡胶木胶合板。     

Development of a novel polyvinyl acetate type emulsion curing agent for urea formaldehyde resin

High formaldehyde emission and poor water resistance are two main disadvantages of urea formaldehyde (UF) resin. For that reason, a novel polyvinyl acetate (PVAc) type emulsion curing agent was developed in this paper. PVAc type emulsions, including PVAc, the co-polymer of PVAc and N-hydroxymethyl acrylamide (PVAc–NMA), and the ternary co-polymer of PVAc, NMA, and urea (PVAc–NMA–urea), were the main components. Water, aluminum chloride, ammonium dihydrogen phosphate, polypropylene glycol, silicone oil, and urea were the other components. Under heating, aluminum chloride and ammonium dihydrogen phosphate often underwent thermal decomposition and hydrolysis in solution, produce free acid to cure UF resin, so the curing agent could enhance the curing rate, and then shorten the curing time. In this curing agent, ammonium dihydrogen phosphate and urea worked as formaldehyde removers and reacted with free formaldehyde in UF resin, thus the formaldehyde emission exuded from the plywood could be effectively limited and reduced. The bonding strength of plywood was not improved very much, especially the dry bonding strength, but the wet bonding strength was little enhanced for the active hydroxymethyl group contained in PVAc–NMA and PVAc–NMA–urea underwent a self-cross-linking reaction to improve the bonding strength and adhesion force to the bonded substrate. More importantly, the results from the industrial production experiments were shown to be very good.     

三种松木单板的胶合工艺条件和胶合性能的改善

用ＵＦ、ＭＵＦ胶制作三种松木胶合板，分别就单板厚度、涂胶量及抽提物含量对胶合性能的影响，松木与柳安混合树种组坯、特殊添加剂对改善胶合性能的作用进行了研究。结果表明：除了老挝松边材ＭＵＦ胶合板以外，１．５和２．０ｍｍ厚的单板胶合强度均达到或超过日本ＪＡＳ普通胶合板的要求。合板胶合强度随单板厚度增加而下降，在一定范围内增加涂胶量可以提高合板胶合强度，混合组坯及施加特殊添加剂具有改善松木单板胶合性能的作用。     

PEI/APP改性脲醛树脂制备阻燃胶合板及性能

以聚乙烯亚胺(PEI)为改性剂处理聚磷酸铵(APP)制备得到APP@PEI阻燃体系,并将其加入到脲醛树脂(UF)中,制备阻燃胶合板.研究了APP@PEI对UF胶黏剂理化性能的影响,并进一步探讨其对胶合性能及阻燃性能的影响.结果表明:APP、PEI和APP@PEI对UF的黏度、pH和固化时间均有影响.当APP添加量为10...     

Effects of intumescent formulation for acrylic-based coating on flame-retardancy of painted red lauan (<Emphasis Type="Italic">Parashorea</Emphasis> spp.) thin plywood

Acrylic emulsion based painted red lauan plywood (Parashorea spp.) is most commonly used for indoor furnishings. This study investigated the enhancement of the fire retardance of painted plywood by interaction among four major components of intumescent formulation: (1) acrylic emulsion resin as binder resin (BR), (2) pentaerythritol as carbonizing substance (CS), (3) melamine as foam producing substance (FPS) and (4) ammonium polyphosphate as dehydrating agent (DA). Effects of changing BR/CS ratios (designated as FRA series) and FPS/DA ratios (designated as FRM series) on flame-retardance of painted plywood were investigated using a cone calorimeter. The intumescent formulation significantly enhanced fire retardancy of painted plywood by exhibiting lower peak release rates and longer times to reach peak release rates, compared with uncoated plywood (UP) panel and plywood panel solely coated with acrylic emulsion resin. Lower BR content in the FRA series and lower FPS content in the FRM series were shown to enhance flame retardancy of painted plywood. The positive correlation between total heat release values under increasing combustion duration and incremental changes of BR and FPS contents in two series further verified the above findings. Consistent with the observed flame retardancy enhancement of painted plywood, lower heats of combustion and weight losses for paints in the FRM series were also identified by oxygen bomb calorimeter measurements and thermogravimetrical analysis. Infrared analysis of the chars indicated the formation of phosphate ester linkages with the lowest BR content in the FRA series and the lowest FPS content in the FRM series showing superior enhancements of flame retardancy for painted red lauan plywood.     

油菜籽蛋白-丙烯酸酯乳液共混胶黏剂的制备

将油菜籽蛋白和丙烯酸酯乳液共混制备胶黏剂,以其代替部分醛类胶黏剂用于胶合板生产。采用单因素试验方法,确定油菜籽蛋白和丙烯酸酯乳液添加比例;采用正交试验方法,优化该胶黏剂制备胶合板工艺;通过热重分析评价胶黏剂的热稳定性。结果表明:油菜籽蛋白与丙烯酸酯乳液配比为8∶2,胶合板制备理想的热压工艺为二苯甲烷二异氰酸酯(MDI)添加量4%、热压温度140℃、热压时间700s、热压压力0.8MPa,板材剪切强度1.71MPa,符合GB/T9846—2015《普通胶合板》中Ⅱ类胶合板的要求。     

落叶松树皮碱抽出物胶粘剂的研究

研究了落叶松树皮碱抽出物制造胶粘剂的生产工艺。碱抽出物胶粘剂压制的桦木，杨木三合板的检测结果，符合国家标准Ⅰ类板的质量要求，并对胶粘剂的经济效益进行了分析。     

封闭异氰酸酯改性脲醛树脂制备胶合板

采用亚硫酸氢钠封闭异氰酸酯改性UF树脂制备胶合板,研究了制板用混合胶液的比例、热压时间、热压温度等热压工艺对胶合板性能的影响,结果表明,在UF/PAPI=100/10、热压温度为110℃、热压时间为4min时,所制备胶合板的甲醛释放量达到国家标准,并且具有较高的胶合性能.     

电磁屏蔽功能胶合板的研究

以镍粉、石墨粉、不锈钢纤维和铜纤维作为导电单元,脲醛树脂为胶黏剂,制备3层落叶松胶合板,研究不同导电单元和涂胶量对板材电磁屏蔽效能(ESE)及胶合强度的影响.结果表明,纯镍粉填充的胶合板的ESE几乎为零;后3种导电单元填充的胶合板ESE分别达到5～10 dB,17～21 dB和6～17 dB;试板的胶合强度除不锈钢纤维添加量为80 g/m2时低于国家标准外,其余条件下均达到或超过国家相关标准要求.     

水性异氰酸酯胶合板与细木工板的研究

以水性异氰酸酯胶粘剂试制胶合板和细木工板。研究结果表明,单板的材种和施胶量等对异氰酸酯胶合的板材性能有较大影响;采用异氰酸酯,胶合板用胶量较少,在施胶量为200g/m~2时,马尾松、杨木、荷木、枫木单板制成的胶合板胶合强度均能达到GB/T5849-1999的要求,枫木作中板的细木工板在施胶量为250g/m~2时胶合强度和横向静曲强度均达到国家标准;根据试验结果并结合生产实际的成本分析表明,胶合板成本增加了81～189元/m~3,细木工板的成本增加了120元/m~3和104元/m~3。     

水性异氰酸酯交联剂的应用研究

采用不同链长的聚醚多元醇与多亚甲基多苯基多异氰酸酯（PAPI）反应,制备了两种不同结构的水性异氰酸酯（P-C、P-D）,联剂分别加入到氧化玉米淀粉胶黏剂和脲醛树脂胶黏剂中,以改善胶黏剂的胶接性能。通过粘接强度测试研究不同结构、不同用量的水性异氰酸酯对改性胶黏剂的胶接强度和耐水性的影响。实验结果表明：氧化玉米淀粉和脲醛树脂中加入水性异氰酸酯交联剂制备胶合板,胶接强度及耐水性均有显著提高。氧化玉米淀粉胶黏剂中加入10%的水性异氰酸酯P-D后,所制备胶合板的干态剪切强度可达2.64MPa。脲醛树脂胶黏剂中加入7.5%的P-D后,干态、湿态剪切强度分别为1.24MPa和1.23MPa,甲醛释放量为0.31mg/L,达到E0级标准。     

等离子体改性热塑性树脂薄膜制备环保胶合板试验

为获得无甲醛释放的环保胶合板,将热塑性树脂薄膜(低密度聚乙烯(LLDPE)、聚丙烯(PP)、聚氯乙烯(PVC))用作胶黏剂,并利用空气介质阻挡等离子体对热塑性树脂薄膜进行表面改性处理以提高薄膜与杨木单板的界面相容性,从而获得性能良好的环保胶合板。研究了等离子体处理对胶合板胶合性能的影响,并从等离子体处理对热塑性树脂薄膜表面化学组分及其对胶合板界面形貌的影响分析其胶合机理。结果表明:在等离子体处理功率为4.5 kW、处理时间为8 m/min的条件下处理热塑性树脂薄膜,胶合板的胶合强度得到显著提高,LLDPE/杨木胶合板的胶合强度从0.49 MPa增至0.81 MPa,PP/杨木胶合板的胶合强度从0.65 MPa提高到0.84 MPa,均达到Ⅱ类胶合板标准要求。其中用等离子体处理后PVC与杨木制备的胶合板能满足Ⅰ类胶合板的标准要求,胶合强度达到0.79 MPa。XPS分析表明,等离子体改性热塑性树脂薄膜的表面发生了氧化反应,引入了含氧官能团,提高了薄膜表面极性,有利于提高薄膜与杨木单板之间的相互作用,从而使得胶合板的界面胶合更为紧密,说明等离子体处理后树脂与杨木单板的相容性提高,树脂能在单板表面更好地附着。热塑性树脂薄膜与杨木单板制备的胶合板仅有极微量甲醛释放,其主要源于木材自身,远低于国家标准对人造板甲醛释放限量的要求。研究证明等离子体处理能明显改善热塑性树脂薄膜与杨木单板的界面相容性。     

生物乙醇木质素-PAE改性大豆蛋白胶黏剂合成工艺研究

将生物乙醇木质素与自合成的聚酰胺多胺环氧氯丙烷(PAE)树脂进行接枝共聚改性大豆蛋白,制备环保型胶合板用胶黏剂,并通过单因素试验确定了木质素种类、木质素与PAE质量比、木质素与PAE树脂反应时间、大豆蛋白添加量等工艺条件对大豆蛋白胶黏剂胶合强度的影响。结果表明:当选用生物乙醇木质素与PAE进行接枝共聚、木质素与PAE质量配比为1∶4、反应时间为30 min、大豆蛋白添加量为50%(以木质素-PAE总质量而言)时,制得的三层胶合板湿胶合强度(1.03 MPa)可达到GB/T 9846—2015Ι类杨木胶合板的指标要求。     

阻燃桉树胶合板的初步研究

以磷酸二氢铵（MAP）溶液为阻燃剂,通过浸泡尾叶桉单板,研究了单板的载药量;以Ⅱ类胶合强度为指标,利用正交试验对常规胶合板生产工艺进行了优选。在此基础上,选取浸泡时间和最优生产工艺试制了阻燃桉树胶合板,并对其Ⅱ类胶合强度和燃烧性能进行了检测。结果表明：不同厚度尾叶桉单板的载药量随浸泡时间的延长呈现相似的增长规律;试验所得常规尾叶桉胶合板最优生产工艺为施胶量210 g.m-2、热压温度130℃、热压时间8 min,该条件下胶合板的Ⅱ类胶合强度达到了2.01 MPa;单板浸泡8h后,单板平均载药量为32.05 kg.m-3,所制得阻燃胶合板氧指数提高了13.9%,炭化长度减少了8.3 mm（26.2%）,阻燃性能明显提高,而胶合强度也达到了Ⅱ类胶合板的国家标准。研究初步证明利用常规桉树胶合板生产工艺生产阻燃桉树胶合板是可行的。     

魔芋葡苷聚糖/壳聚糖共混胶黏剂应用于胶合板的研究

以胶合强度为考察指标,进行魔芋葡苷聚糖/壳聚糖共混配比胶黏剂工艺的制备研究.试验结果表明,胶黏剂中各组分用量的较佳参数为:壳聚糖1%,魔芋葡苷聚糖1.5%,NaOH为1%.此配比制备的胶黏剂压制的胶合板,干状胶合强度最大;在壳聚糖1%,魔芋葡苷聚糖1.5%,NaOH为2%的配比时,胶合板的湿状胶合强度最大.     

聚酰胺多胺环氧氯丙烷树脂大豆胶黏剂制备及性能研究

采用己二酸(AA)、二乙烯三胺、环氧氯丙烷(ECH)合成聚酰胺多胺环氧氯丙烷树脂(PAE),将其与大豆蛋白按比例混合制备PAE大豆胶黏剂。在合成预聚体(PA)后,通过单因素试验,探究AA与ECH摩尔比、大豆蛋白添加量对胶合板胶合强度的影响,研究了PAE对大豆蛋白的改性作用及胶接机理。结果表明:在胶黏剂合成过程中AA与ECH摩尔比为1:1.0,大豆蛋白添加量为30%,热压温度为120℃、压力1.0 MPa、热压时间6 min条件下,PAE大豆蛋白胶黏剂胶合强度可达1.02 MPa,满足GB/T 9846-2015Ι类板指标要求。     

Manufacture of plywood bonded with kenaf core powder

Kenaf (Hibiscus cannabinus L.) core powder was used as a binder to manufacture three-ply plywoods of sugi (Cryptomeria japonica D. Don) by conventional hot pressing under various manufacturing conditions: hot-pressing conditions (pressure, temperature, and time) and powder conditions (grain size, spread volume, and moisture content). The adhesive shear strength and wood failure of plywoods were measured in accordance with the Japanese Agricultural Standard (JAS) for plywood. The result showed that fine kenaf core powder played a role as an effective binder when plywoods were pressed at high pressure, which caused extreme compression of veneer cells. In addition, the adhesive shear strength of plywoods in dry conditions was high regardless of pressing temperature and time, but it was sensitive to pressing temperature and time in wet conditions. The highest adhesive shear strength was obtained from plywoods manufactured with kenaf core powder (grain size 10 μm, spread volume 200 g/m², moisture content 8.6%) under hot-pressing conditions (pressure 5.0 MPa using distance bars 4 mm thick, temperature 200°C, time 20–30 min). However, the plywood could not meet the requirement for the second grade of plywood by JAS because of its low water-resistance properties. Part of this article was presented at the 58th Annual Meeting of the Japan Wood Research Society, Tsukuba, March 2008, and the 10th World Conference on Timber Engineering, Miyazaki, June 2008     

羧基丁苯胶乳改性脲醛树脂胶粘剂的研究

利用羧基丁苯胶乳对脲醛树脂胶粘剂进行改性,同时在脲醛树脂合成过程中加入一定数量的玉米淀粉等改性剂,进一步提高改性脲醛树脂的综合性能,降低生产成本。羧基丁苯胶乳改性脲醛树脂胶粘剂具有游离甲醛含量低、生产工艺简单等特点,生产出的胶合板的胶合强度和甲醛释放量均满足国家标准。     

Differential scanning calorimetry characterization of the cure of phenol-formaldehyde adhesive in the presence of copper-based preservative treated wood

The interference of copper based preservative treated southern yellow pine (SYP) on the cure of phenol-formaldehyde adhesives was investigated by using differential scanning calorimetry (DSC). Copper preservatives used in this study include copper azole (NS), alkali copper quat (ACQ)-type C (NW). Three commercial phenol-formaldehyde (PF) adhesives used for oriented strand board (OSB) face area, core area and a plywood adhesive were studied. The curing peak temperature and peak time of OSB core and face PF resin shifted to higher temperature and duration in the presence of CCA, NS, and NW-treated SYP compared to that in untreated SYP. The above treatments interfere with the cure of OSB core and face PF resin. Untreated SYP showed a curing accelerating effect on the cure of plywood adhesive, but the accelerating effect of copper-treated SYP on the cure of plywood resin was not significant.