碱木素-大豆蛋白胶黏剂在胶合板中的应用研究

探讨了一种新型木素基无醛胶黏剂在三层杨木胶合板中的应用。为了探究经活化还原处理后的碱木素与大豆蛋白共混制备生物质胶黏剂的工艺,以胶合板的胶合强度为性能指标.采用单因素实验,对漆酶加入量、碱木素,大豆蛋白共混比例、热压温度和热压时间等因素对其影响进行了研究。结果表明.最优工艺参数为:漆酶加入量为木质素的3/5,碱木素一大豆蛋白共混比例1:1,热压温度130℃,热压时间10 min,且此碱木素一大豆蛋白胶合体系的胶合强度达到并超过国家Ⅱ类胶合板的要求。     

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。     

三聚氰胺树脂纸质装饰胶合板的生产方法

目前。国内生产装饰胶合板有很多方法。最常用的三聚氰胺树脂装饰胶合板加工方法是将三聚氰胺树脂装饰板(塑料贴面板)与涂胶的胶合板或数层单板经热压或冷压方式胶合而成。用这种方法加工的装饰胶合板,虽然具有塑料贴面板的一切性能,但由于成本较高、易产生翘曲等,使应用范围受到一定限制。有的在胶合板表面上用胶粘剂胶贴聚氯乙烯薄膜贴     

酶在木材胶合中的应用

介绍了酶用于木材胶合的研究及进展。利用酶可直接活化木纤维或木刨花中的木素使其自身胶合，也可使酶与制浆过程中分离出来的木素反应，得到与酚类化合物类似的胶粘剂，用以胶合木纤维或木刨花。利用酶催化氧化木素的途径生产人造板，无污染且安全可靠。     

胶合木胶合质量影响因素浅析

本文分析了胶合木用胶粘剂的适用期，木材含水率、环境温度等因素对胶合木胶合质量的影响。     

E1胶合板用低成本脲醛树脂胶粘剂的研究

以尿素和甲醛为原料,在特定配方和工艺条件下合成脲醛树脂胶粘剂,根据它们的不同性能分别作为主体树脂、甲醛捕捉剂和强化剂。通过实验设计将三者进行了复配。研究结果表明:在主体树脂中加入10％的甲醛捕捉剂、5％-15％的强化剂和20％的面粉可以制得E1胶合板用胶粘剂。该胶粘剂成本较低,能显著提高胶合板的胶合性能,降低甲醛释放量。     

漆酶活化木素磺酸盐条件对胶合板强度的影响

采用漆酶活化木素或其磺酸盐制备胶黏剂用于人造板生产,可以消除游离甲醛的污染问题。以漆酶、工业木素及其磺酸盐、杨木为原料,在处理时间分别为30、45、60min,pH值分别为3．5、4．5、5．5,温度20℃条件下,分别以漆酶处理工业木素、木素磺酸钠和木素磺酸铵三种底物制备胶黏剂,然后在热压时间30min,压力4．5～5MPa,热压温度150℃条件下生产杨木胶合板。结果表明,除漆酶木素磺酸钠胶合体系外,漆酶木素和漆酶木素磺酸铵的胶合体系的胶合板胶合强度均达到并超过国家Ⅲ类胶合板的要求。     

降低胶合板耗胶量的措施及其效果综述

目前,胶粘剂成本的高低是影响人造板企业经济效益的主要因素之一。胶粘剂中添加填充剂、选择新的施胶法、采用高含水率胶合技术、对单板进行预处理、降低树脂的固定含量、提高单板质量、采用无胶胶合技术,都是减少胶合板耗胶量的具体措施。     

桉木与杨木阻燃胶合板的性能对比分析

采用磷氮硼复合阻燃剂浸渍处理桉木和杨木单板,分别制备5层阻燃胶合板,检测其物理力学性能和阻燃性能.结果表明:阻燃胶合板的胶合强度,均满足GB/T 9846-2004《胶合板》中Ⅱ类要求,抗弯性能满足LY/T 1738-2008《实木复合地板用胶合板》要求;两树种胶合板相比,杨木阻燃胶合板的胶合强度较好,桉木阻燃胶合板的抗弯性能及阻燃性能更优.     

粉状落叶松单宁酚醛树脂胶生产胶合板的研究

试验研究了粉状落叶松单宁酚醛树脂胶（ＴＰＦ）的调胶工艺和胶合板胶合工艺，结果表明：粉状ＴＰＦ树脂胶与水按１０：９的重要比混合均匀并陈效２４ｈ后再使用，胶合板的胶合强度比较理想；在胶液中添加５％的面粉或５％面粉及５％木粉，可以改善胶粘剂的性能，最后，确定粉状ＴＰＦ树脂胶生产马尾松胶合板的最佳工艺条件。     

木质纤维素及其组分转化木材胶粘剂的发展趋势

木质素是造纸工业废液中的主要成分。其具有和酚醛树脂相似的结构, 因此可以部分替代苯酚用于酚醛树脂的生产。但是由于木质素化学结构复杂, 具有化学反应活性的位点少、反应官能团所收到的空间位阻大, 一般添加量不超过10%~20%。有机溶剂法制浆分离的木质素分子量大, 纯度高, 酚醛树脂允许的添加量可达20%~30%, 但是要求提高固化温度、延长固化时间来克服木质素反应活性低的限制。对木质素进行化学改性如羟甲基化、酚解、醇解、还原等, 可以降低分子量, 增加活性基团如酚羟基的含量、并使苯环上更多的活性位点暴露出来, 从而提高木质素的化学反应活性。酚醛树脂经过改性木质素的允许的添加量可达30%~40%。部分木质素含量高的木质纤维素类原料如核桃壳粉等, 经过研磨和化学活化处理后可以直接添加到酚醛树脂中, 部分替代苯酚而不对胶接性能产生影响。环碳酸酯类和多元醇混合物被用来作为全新的液化剂来把木质纤维素快速液化为有用的化学原料。所得到的液化产物具有较高的反应活性, 是今后利用木质纤维素开发绿色木材胶粘剂的一条可资利用的途径。     

Sorption of kraft lignin from spent liquors on pulp fibres

In this investigation, the sorption of kraft lignin (KL) from spent liquors, membrane filtrated and model KL liquors on fully bleached softwood kraft pulp fibres, was studied. The time, temperature and alkalinity during the sorption experiments were chosen to reflect the conditions of black liquor impregnation of chips before the cooking operation. The amount of sorbed KL was estimated by brightness and kappa number measurements. A linear correlation between the k value and the kappa number was found. Among the parameters investigated, the concentration of metal non-process elements was found the most crucial for the sorption of KL on pulp fibres under black liquor impregnation. The influences of KL concentration, metal ion profile and KL molecular weight distribution on the KL sorption behaviour under black liquor impregnation are discussed.     

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.     

A mathematical model of kraft pulping related to the alkali concentration in the cooking liquor

Summary A new mathematical model for checking and controlling the kraft pulping process has been derived. The model is based on the modified relationship between the lignin content and the alkali concentration of a cooking liquor expressed as the ratio of lignin/active alkali vs. concentration of the active alkali in a cooking liquor. The derived model characterizes the variation of the lignin content of the partially delignified wood or pulp with the concentration of the residual alkali in a cooking liquor during an entire pulping cycle, i.e. during the initial, transition, bulk and residual phases of the kraft delignification. The relationship between the lignin content of the partially delignified wood ships or pulp and the concentration of the residual alkali in a cooking liquor is expressed by the logarithmic straight line equation or its power form. The slope and intercept constants of the derived equation for the individual phase of delignification have different values. Received 5 June 1996     

超声波法活化麦草碱木素及用于PF胶黏剂的研究

麦草碱木素是我国造纸工业重要的剩余物,但是麦草碱木素的结构决定了其反应活性较低,从而使其应用受到较大的限制。笔者根据麦草碱木素的特点分别对比超声破碎仪不同的超声条件(时间:10、20、30、40min;振幅:60、80、100)和不同的溶液质量比(100:0,60:1,20:1)对麦草碱木素的活化效果,并探索用活化后的木素代替部分苯酚(10%、20%、30%、40%)制备酚醛树脂胶黏剂的可行性。研究结果表明:超声波作用可显著提高酚羟基的含量。超声波作用时间在20min、振幅80、溶液质量比20:1时效果相对较好。经过超声波活化的木素按20%的量替代苯酚制备LPF,压制的胶合板的胶合强度都达到国家Ⅰ类胶合板的要求,并能与未改性的酚醛树脂(PF)胶黏剂相媲美。     

Oxidation of hardwood kraft-lignin to phenolic derivatives with oxygen as oxidant

 A hardwood kraft lignin was oxidized in alkaline medium to obtain phenolic compounds (syringaldehyde, vanillin and its acids). To avoid lignin condensation, the lignin was precipitated from a black liquor with a calcium salt dissolved in a water soluble alcohol. Oxygen was the oxidant employed, and copper (II) and cobalt (II) salts were used as catalysts. Effect of temperature, reaction time, oxygen pressure, alkali concentration and catalyst on yield and product distribution were studied. In all the range of variables lignin conversion and aldehyde yield remains low and the more important effect on aldehyde yield was due to the alkali concentration, which must be fixed at about 2 N. The precipitation method did not significantly increase the aldehyde yield, in contrast with the results of nitrobenzene and CuO oxidations. In catalyzed oxidations, no increase in phenolic aldehydes was observed and, with some catalyst, the conversion into phenolic derivatives was reduced. Lignin conversion into low molecular weight products is responsible for the low phenolic product yield and the type of catalyst could lead the oxidation into phenolic products or into low molecular weight acids. Received 23 November 1998     

新型酚醛树脂改性大豆蛋白基胶黏剂的研究

以脱脂大豆粉为原料制备大豆蛋白基胶黏剂(豆胶,S),以普通甲醛制备的酚醛树脂(PF_1)和高浓度甲醛制备的酚醛树脂(PF_2)为交联剂,使用前将两者直接混合得酚醛树脂改性豆胶(PF_1/S、PF_2/S)。利用差示扫描量热(DSC)、红外光谱(FT-IR)、动态热机械性能(DMA)和核磁共振碳谱(~(13) C NMR)分析对产品性能进行了测试与表征。结果表明:等物质的量之比条件下,高浓度甲醛较之普通甲醛制备的酚醛树脂改性豆胶胶合板干、湿剪切强度分别提高4.3%和11.6%,并且强度稳定性好;动态DSC分析表明,PF_2可以降低豆胶体系的固化温度和活化能,与豆胶的交联反应较容易;~(13) C NMR分析表明,PF_2体系羟甲基达88.73%,明显高于PF_1的80.91%;FT-IR分析证实酚醛树脂与豆胶中的氨基发生反应,并且PF_2反应效率更高;DMA分析表明,PF_2/S能够改善胶合产品的力学性能和热稳定性,降低豆胶的固化反应起始温度,提高固化反应速率。     

酶解木质素改性酚醛树脂胶黏剂的研究

利用秸秆发酵制备能源酒精的残渣中提取的酶解木质素(EHL),部分代替苯酚合成改性酚醛树脂胶,并热压制得胶合板.测定了胶合板的胶合强度,改性树脂胶的黏度、固含量、水混合比、可被溴化物、游离酚、游离醛等性能指标.结果表明:木质素替代量达20%时,各项性能仍能基本达到国家标准Ⅰ类板的要求,特别是耐水性十分良好,水煮两次后胶合强度仍远大于国家标准Ⅰ类板≥0.7MPa的要求.     

脱甲基硫酸盐木质素代替酚在木材粘合剂中的应用

硫酸盐木质素经脱甲基增加了与甲醛反应的活性，且因在木质素结构中形成了邻苯二酚结构，其反应性能较苯酚更活泼。溶于碱溶液的脱甲基木质素与甲醛一起直接加入粘合剂中，热压时，不增加热压时间。有可能以脱甲基木质素完全取代酚并得到满意的胶合板粘合剂，脱甲基木质素的生产成本约为苯酚的一半。