桉木APMP制浆过程浆中残余木素分子量的变化

利用凝胶渗透色谱法和元素分析法测定了尾叶桉酶解木素在APMP制浆及漂白过程的分子量变化。研究结果表明：由于HOO-的特殊作用,制浆及漂白之后,浆中剩余木素的平均分子量相对有所增大。     

桉树抽出物在硫酸盐法制浆过程中的作用机理

研究了桉木抽出物中多四类化合物在硫酸盐法制浆过程中的作用机理,结果表明：桉水硫酸盐法制浆的蒸煮历程可分为三个阶段。多酚类化合物对破的消耗突出表现在前期和中期,多酚类化合物对得率变化、木素脱除以及碳水化合物溶出的明显影响表现在后期高温保温阶段。桉木蒸煮前预处理除去多酚类化合物对降低减耗和对蒸煮后期脱术素有利。     

桉木单板贴面无机桉木碎料板制备及性能

以桉木单板和无机胶黏剂为原料对桉木碎料板进行贴面处理,研究了施胶量、成型压力、脱模养护时间对桉木碎料板弯曲性能的影响以及贴面处理对板材阻燃性能的影响.结果表明:施胶量、成型压力和脱模养护时间对木单板贴面桉木碎料板弯曲性能影响均显著.随着施胶量的增加,板材的静曲强度和弹性模量均先增大后减小,施胶量为320 g/m2时板材静曲强度和弹性模量分别达到最大值35.26 MPa和3863 MPa;随着成型压力的增加,板材的静曲强度和弹性模量也都先增大后减小,成型压力为1.5 MPa时,板材的静曲强度和弹性模量分别达到最大值35.37 MPa和3900 MPa;随着养护时间的增加,板材的静曲强度和弹性模量逐渐增大.养护3周后板材静曲强度和弹性模量基本趋于稳定.贴面处理使板材前期的热释放速率和热释放总量增大,阻燃性能降低.150 s后,基本表现出桉木碎料板贴面前的阻燃性能.     

澳大利亚王桉硫酸盐制浆性质研究

运用硫酸盐法及CEHD标准四段漂白法对澳大利亚产王桉进行了制浆、漂白及抄纸性能研究。结果表明,王桉宜于抄造包装用纸及多种文化用纸,是一种良好的制浆造纸用树种。     

碱木素填充软质聚氯乙烯的研究

制浆造纸工业排放的大量黑液,经凝聚剂处理,脱水后制得碱木素。碱木素是一种天然高分子材料,可作为高分子材料的填充剂、改性剂。本文详细介绍了碱木素填充软质聚氯乙烯的实验过程及工艺条件。并讨论了碱木素填充后对样品的化学、生物性能的影响。     

速生桉木硫酸盐法制浆过程中甲醇生成量的预测模型

以速生桉木硫酸盐法制浆为研究对象,考察了制浆过程中有效碱浓度、H因子(时间和温度)对甲醇生成量以及残余有效碱浓度变化的影响,研究发现制浆过程残余有效碱浓度与蒸煮H因子的负指数呈线性关系,结合这一关系从动力学角度建立了引入碱浓动态变化的制浆过程中预测甲醇生成量的数学模型。结果表明该模型能很好地预测速生桉木硫酸盐法蒸煮过程中各工艺条件下的甲醇生成量(R² 0.990)。模型的预测效果表明,温度对甲醇生成量影响显著,而初始有效碱浓度对甲醇生成量影响较小。实际生产中,可根据该模型对各工艺条件对甲醇生成量影响程度的预测效果适当改变工艺条件,以控制制浆过程中单位木素脱除量的甲醇生成量。     

碳纤维增强桉杨复合胶合板的制备及性能研究

为开发碳纤维/木基复合材,设计了全桉木、全杨木、杨桉交错、桉杨交错四种结构用桉杨复合胶合板,采用碳纤维(CF)进行表面增强,研究增强前后桉杨复合胶合板的物理力学性能以及保温性能,探讨老化前后四种结构之间的性能变化。结果表明:经碳纤维表面增强后,桉杨交错结构吸水厚度膨胀率为2.6%,下降幅度为44.7%,吸水率下降幅度为46.5%;四种结构浸渍剥离性能均满足标准,最好为桉杨交错结构;桉杨交错结构老化前纵向静曲强度为98.5 MPa,提高率为107.4%,纵向弹性模量为15810 MPa,提高率为129.8%,老化后杨桉交错结构纵向弹性模量为10150 MPa,提高率为176.3%,且杨桉交错结构胶合强度可达1.74 MPa,但对于横向静曲强度、弹性模量和胶合强度提高均较小。综合而言,碳纤维增强后物理力学性能较好的结构为杨桉交错和桉杨交错,总体反映了桉杨复合胶合板结构上纵横强度比差异较大,在实际应用中根据需求调整纵横强度设计比例;经碳纤维表面增强后桉杨复合胶合板导热系数均值为0.44 W/(m·℃),导热系数值接近保温材料,碳纤维表面增强后对其保温性能影响不明显。     

一种降低细菌纤维素分子量的方法

以实验室自行筛选的木醋杆菌(Acetobacter xylinum)为菌种,海南椰子水为主要培养体系,在生物合成过程中向培养基中添加半乳糖醛酸,采用静态培养方法制备了细菌纤维素(BC),对BC的结构和性能进行了研究;结果表明:添加半乳糖醛酸后,BC的产率、持水性能及热稳定性有所下降,而结构特征和结晶性能与不添加半乳糖醛酸的BC差别不大;但产物衍生化后的分子量却降低很大,约10万左右;有望用半乳糖醛酸代替蔗糖为碳源生产低分子量的细菌纤维素。     

含乙酸木素复合型聚氨酯材料的合成及其性能研究

对以乙酸木素(AL)为原料合成复合聚氨酯材料的方法及其特性进行了研究和探索。对乙酸法制浆废液的木素进行了提取和纯化,并采用红外光谱和GPC研究了乙酸木素的结构和分子质量。以乙酸木素代替部分聚乙二醇合成了AL-TDI-PEG复合聚氨酯,并对其进行了拉伸强度、最大伸长率、DSC和TGA热性能的测定和红外光谱分析,而且也对木素用量和这些物理性能之问的规律进行了研究和探索。实验结果表明,木素-TDI-PEG复合PU片具有较好的拉伸强度、伸长率和耐热性。当木素用量为20％时,强度达到最大,而超过20％时,强度有所降低,说明乙酸木素的加入对PU的强度有一定的影响。     

改性大豆蛋白胶膜纸饰面细木工板的浸渍剥离性能研究

采用杉木芯板和桉木单板为原料,以热压温度、热压时间、桉木单板含水率为影响因素设置单因素和正交试验,并通过检测板坯的浸渍剥离长度,对改性大豆蛋白基胶粘剂浸渍膜纸饰面细木工板的热压工艺进行了研究。研究结果表明:各因素对板坯浸渍剥离性能影响的主次为热压温度桉木单板含水率热压时间;当杉木板芯厚度为12 mm、桉木单板厚度为3 mm、单面施胶量为250 g/m2、热压压力为0.8 MPa时,较优的热压工艺参数为热压温度120℃、热压时间520 s、桉木单板含水率为12%。     

Simulating the impact of kraft pulping and bleaching parameters on Eucalyptus camaldulensis pulp properties using MATLAB

In this work, Eucalyptus camaldulensis was evaluated as the raw material for chemical pulp under different pulping and bleaching conditions. The pulping was carried out at different H‐factors, and at different effective alkalis. The resulting pulps were then oxygen delignified and bleached using various dosages of bleaching chemicals in a D₀EpD₁ sequence. The effect of independent variables (pulping or bleaching variables) on dependent variables (pulp properties) was analysed based on the multivariable least square method via MATLAB software. An agreement was found between the results predicted from the models and the experimental data. To obtain a kappa number of 15, the optimum pulping conditions were a temperature of 155°C, a time of 225 min, and an EA of 23%. Also, the hexenuronic acid (HexA) content of cooked pulp was significantly decreased in the chlorine dioxide bleaching stages, and was only marginally related to the final HexA content of bleached pulps.     

掺加建筑垃圾分选粉体对硅酸盐水泥熟料 烧成的影响*

在对建筑垃圾分选粉体的物理性质和化学性质进行分析的基础上,进行了水泥生料中掺加部分建筑垃圾分选粉体煅烧硅酸盐水泥熟料的试验研究。试验表明:(1)试验所用的建筑垃圾分选粉体,可以作为水泥工业生产原料使用,这是建筑垃圾实现资源化再生利用的途径之一;(2)试验条件下,在水泥生料中掺入12.7%的建筑垃圾分选粉体,对煅烧的水泥熟料物理性能未产生不良影响。     

Chemical and structural characterization of alkaline‐extractable hemicelluloses from various eucalyptus species

Eucalyptus species are currently one of the main feedstock for pulping and papermaking industry in China. In the present study, alkali‐extractable hemicelluloses were isolated from different eucalyptus species (Eucalyptus camaldulensis, E. urophylla × grandis, and E. urophylla × E. tereticornis) at mild conditions prior to pulping. Structural characterization of these hemicellulosic polymers based on monosaccharide, molecular weight, Fourier transform infrared, ¹H, ¹³C, and two‐dimensional heteronuclear single quantum coherence nuclear magnetic resonance analysis revealed that these alkali‐extractable polysaccharides shared the common structure composed of the (1→4)‐linked‐β‐D‐xylopyranosyl backbone with 4‐O‐methyl‐α‐D‐glucuronic acid attached to O‐2 of the xylose residues. The potential structures of the alkali‐extractable hemicelluloses were proposed based on the comprehensive analysis. The well‐characterized structures of these hemicelluloses could enlarge the industrial application of these hemicelluloses from the Eucalyptus species in a biorefinery process. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 130: 2390–2398, 2013     

YZ-84润滑减阻剂在金刚石钻探、绳索取心中的应用

YZ-84润滑减阻剂是以腐植酸盐为y型原料,用造纸废液为Z型原料,以及其他原料制成。它具有润滑、减阻性能好,清洗能力强,性能稳定,可复配使用,不结垢、不粘管,使用方便,成本低等特点,完全能满足新型小口径金刚石钻机高速钻进、绳索取心的技术要求。     

木薯双醛淀粉制备木材用胶粘剂的研究

以木薯淀粉为原料、高碘酸钠为氧化剂,在一定条件下制得双醛淀粉(DAS);然后以过硫酸铵(APS)为引发剂、聚乙烯醇(PVA)为保护胶体和醋酸乙烯酯(VAc)为DAS的接枝单体,再配合其他助剂制得双醛接枝淀粉基木材用胶粘剂。结果表明:当w(DAS中醛基)=20%、m(DAS)∶m(VAc)=1∶2.5、w(PVA)=75%、VAc为25 mL、接枝反应温度为65℃和反应时间为3 h时,胶粘剂的干、湿强度分别为3.0、2.4 MPa。     

粘结剂对无烟粉煤型焦质量的影响

以低阶太西无烟煤和是天湖山无烟煤为原料,采用冷压成型工艺,研究了粘结剂种类和添加量对型焦质量的影响,对实验数据进行分析,得到了型焦质量随粘结剂性质的变化规律,并确定了用无烟煤生产优质型焦的最佳粘结剂种类和配比,此餐,从微观结构方面研究了无烟煤与粘结剂在高温下的粘结成焦机理。     

亚铵制浆废液资源化及其在造纸和农业经济中的作用

以亚铵法制浆造纸废液为原料开发了数种新型系列肥料,并通过在不同地区不同作物上进行应用评价.结果表明,这一举措不仅使造纸废液变废为宝,在消除污染的同时给造纸企业带来可观的经济效益;而且生产的多种肥料都显示出很好的增产、增质效果,并能提高作物的抗逆性.目前,这种对废液的循环利用是适应现代农业可持续发展的有效方法.     

Impact of effective alkali and sulfide profiling on Eucalyptus globulus kraft pulping. Selectivity of the impregnation phase and its effect on final pulping results

BACKGROUND: Eucalyptus globulus is an important wood source for paper production and, in the last few years, great efforts have been made to assess its chemical specificities and improve the kraft pulping efficiency. Despite the existence of several works concerning mostly the kinetics of E. globulus kraft pulping there is a lack of systematic studies on the initial phase of pulping as well as on the impact of effective alkali (EA) charge profiling on the kraft pulping performance of this species. The aim of the present work is to assess the effect of initial effective alkali and sulfide charges on the lignin and carbohydrates removal on the impregnation phase and to investigate the effect of EA splitting charge on the whole E. globulus pulping process efficiency. RESULTS: When the EA charge at impregnation phase increases, the amount of dissolved wood increases until it reaches a constant value of about 20%. Maximum polysaccharide removal at impregnation phase was about 10% of total wood weight. Glucose removal during impregnation was attributed to the degradation and/or dissolution of E. globulus glucans. For EA charges at impregnation phase higher than ～15%, xylan retention on wood was roughly constant. Despite the differences found at impregnation phase on the amount of dissolved wood and lignin removal, it was demonstrated that these differences are almost completely attenuated until the end of the kraft pulping process. CONCLUSION: In the case of E. globulus, for a constant effective alkali charge, alkali profiling does not affect the whole kraft pulping performance. Copyright © 2007 Society of Chemical Industry     

Kraft pulping of Eucalyptus nitens wood chips biotreated by Ceriporiopsis subvermispora

Eucalyptus nitens and E. globulus are wood species used in kraft pulping in Chile and Australia. Although E. nitens adapts very well to cold regions it requires more severe cooking conditions to produce bleachable kraft pulps. An attempt was made to find out whether a pre‐treatment with Ceriporiopsis subvermispora would improve its performance during kraft pulping and the pulp properties. The biotreatment of the chips carried out for a period of 15 days resulted in 13.3% lignin loss and a limited glucan degradation (2%). The pulping of biotreated samples required lower active alkali charge to reach the target kappa number compared to the control untreated sample and exhibited better pulping selectivity. The pulp yield increased by 3% and 1.5% for the pulps of 22 and 16 kappa numbers, respectively. The biotreated pulp's strength properties were improved and were similar to those of E. globulus reference pulp. Copyright © 2006 Society of Chemical Industry     

PET熔体直纺差别化探索

在熔体直纺的熔体管道上,采用在线添加技术,通过PET与改性剂共混纺丝生产差别化PET纤维。介绍了该工艺的原料、设备、流程、主要工艺条件。讨论了添加组分与主熔体混合的均匀性,添加组分TiO2含量的计算与混合后的实测值的关系,添加TiO2后生产的全消光POY品质的均匀性。