脱墨浆生产线典型部位纤维组分所含黏性物质的特性

对于脱墨浆生产线典型部位(热分散后、后浮选后和成浆池)取样分离的纤维组分,采用四氢呋喃(THF)进行抽提。THF抽出物的FTIR表明:黏性物质中存在的成分包括饱和脂肪酸酯、聚醋酸乙烯类物质、丙烯酸类物质、含有Si-O键的有机硅化合物,以及少量的苯环邻位二取代物。将上述试样及成纸的THF抽出物进行GC-MS分析,检测出的物质可归类于合成黏合剂成分、木材抽出物成分和木素降解产物。可以看出,黏合剂类物质是纤维组分THF抽出物的主要成分。     

废纸脱墨浆生产线典型部位的浆料中细小组分所含黏性物质的分布调查和特性研究

对于脱墨浆生产线典型部位（热分散后、后浮选后和成浆池）取样分离的细小组分,采用四氢呋喃（THF）进行抽提。研究结果表明：从卸料塔到流浆箱,浆料中细小组分的THF抽出物降低了约35%。THF抽出物的傅里叶变换红外光谱（FTIR）分析表明：黏性物质中存在的成分包括饱和脂肪酸酯、聚醋酸乙烯类物质、丙烯酸类物质、含有Si—O键的有机硅化合物,以及少量的苯环邻位二取代物。将上述试样及成纸的THF抽出物进行气相色谱-质谱（GC-MS）分析,检测出的物质亦可归类于合成黏合剂成分、木材抽出物成分和木质素降解产物。可以看出,黏合剂类物质是细小组分THF抽出物的主要成分。     

废纸脱墨浆生产线中胶黏物的分布调查

在脱墨浆生产线典型部位取样分离的纤维组分和细小组分,通过采用四氢呋喃（THF）进行抽提分析,对废纸脱墨浆生产线典型部位浆料的水相中的黏性物质进行了分布调查。结果表明：从卸料塔到流浆箱,浆料中纤维组分和细小组分的THF抽出物分别降低了约74%和35%;溶解与胶体物质（DCS）的含量降低了约57%。     

GPC-ELSD法评价脱墨生产过程胶黏物含量的变化

本文介绍了一种新的胶黏物含量测定方法——凝胶渗透色谱一蒸发光散射检测器联用（GPC—ELSD），并采用该方法考察脱墨浆生产过程中主要工段的浆料、纤维组分和细小纤维组分中的胶黏物的含量变化，评价胶黏物的去除效果。结果表明：脱墨浆生产线中主要工段的浆料、纤维组分和细小纤维组分的THF抽出物组成中胶黏物相对含量最小，木材抽出物次之，其他未知组分相对含量最大；细小纤维组分比纤维组分上含有更多的胶黏物；浮选工序有利于去除细小纤维组分上的胶黏物，但是其他后续工段对细小纤维组分上的胶黏物的除去较难；微细胶黏物的去除、细小纤维组分上胶黏物的去除以及减少白水循环过程中胶黏物的积累可能是解决胶黏物障碍问题的关键。     

脱墨浆DCS水中黏性物质的构成分析

研究了现代化大型脱墨浆及新闻纸生产线上的废纸在热分散后、后浮选后和成浆池处以及成品纸样浆料DCS水中黏性物质的化学组成.甲基叔丁基醚抽出物的GC-MS分析发现,黏性物质由合成黏合剂、木材抽出物、木质素降解产物和其他有机酸类组成.其中,合成黏合剂是抽出物的主要成分,约占黏性物质总量的62%～77%.约11%的呈胶体状态的黏性物质可以在后浮选中被去除.使用阳离子型造纸化学品可以减少浆水体系中部分黏性物质.只有少部分黏性物质附着在纸浆纤维上,70%以上的黏性物质仍留在白水循环系统中,或住造纸机设备机件上沉积.     

废纸脱墨浆抄造薄页包装纸系统中DCS的特性分析

对废纸脱墨浆抄造薄页包装纸系统中溶解与胶体物质（DCS）的特性进行了分析；结果表明，对于脱墨浆，漂白塔浆料中DCS的各项性能指标最高，碱性H₂O₂漂白是引起脱墨浆中DCS溶出较多的主要原因；对于不同位置的纸料，由于纸机白水循环使得流浆箱纸料中DCS的各项性能指标最高。脱墨浆DCS中的碳水化合物主要是各种糖类及醛酸类物质，而甲基叔丁基醚（MTBE）抽出物主要是由不同脂肪酸、树脂酸、甘油酯、甾醇酯和木质素降解产物组成。     

DCS组分对浮选脱墨和脱墨浆漂白效果的影响

在旧报纸脱墨浆浮选过程中,溶解和胶体物质的存在会影响浮选脱墨效率。采用亲脂性抽出物、木素磺酸钠、钙离子和果胶酸作为DCS中主要物质的模型物,研究了它们对旧报纸浮选脱墨以及后续漂白效率的影响。结果表明,浮选过程中,低浓度的亲脂性抽出物能够改善浮选效率,而高浓度的亲脂性抽出物降低浮选效率。浮选过程中果胶酸和钙离子的存在都能够提高浮选效率,降低脱墨浆的残余油墨,提高脱墨浆的白度,但同时纸浆浮选得率有所下降。木素磺酸钠对油墨浮选效率的影响较小。     

新闻纸配浆中DCS的表征及其稳定性

对马尾松化机浆和#8美国废纸脱墨浆中的溶胶物质进行了表征,研究了金属离子对其稳定性的影响.结果发现,马尾松DCS中的脂肪酸和树脂酸(RFAs)主要为脱氢纵酸(DHA)、亚油酸、油酸、棕榈酸等;脱墨浆DCS中主要是亚油酸甲酯、棕榈酸甲酯、棕榈酸、脱氢纵酸等.过氧化氢漂后,树脂酸所占比例大幅上升.DCS中的糖单元主要是半乳糖、甘露糖、半乳糖醛酸、葡萄糖等糖单元.漂白后糖单元的浓度提高,酸性组分的比例升高.DCS稳定性研究发现,H2O2漂白过程中释放出更多的能与Ca2 反应生成絮聚物的酸性物质,稳定性降低;而钠离子对其稳定性几乎没有影响.     

旧报纸漂白脱墨浆中DCS组分及其对纸浆滤水性能的影响

首先对旧新闻纸漂白脱墨浆(BDIP)中溶解与胶体物质(DCS)的组分进行了分析,研究了DCS及其不同组分的模型物对漂白脱墨浆滤水性能的影响。结果表明,BDIP中DCS的主要组分包括木素类物质、脂肪酸和树脂酸以及各种糖类和糖醛酸,如十六酸、9,12-亚油酸、9-油酸、十八酸和海松酸、异海松酸、脱氢枞酸、枞酸以及葡萄糖醛酸和半乳糖醛酸等。DCS的加入能够降低BDIP的滤水性能。当其加入量为总体积的40%时,脱墨浆滤水速率的下降超过37%。PEI的加入能够改善脱墨浆的滤水性能。果胶、木素、脂肪酸和松香酸的加入导致脱墨浆的滤水速度下降,其中主要影响因素是它们本身的电荷密度。     

竹子SCMP碱抽出物的UV和GC-MS分析及其对过氧化氢漂白的影响

竹子SCMP(磺化化学机械浆)碱抽出物的紫外光谱和GC-MS分析及其对过氧化氢漂白影响的研究结果表明,短链小分子类、酚类和脂肪酸类是竹子SCMP碱抽出物的主要成分。其中酚类物质是最主要的组分,其溶出量随碱抽提过程中NaOH用量的增加而增多,同时竹子SCMP过氧化氢漂白浆的白度也明显提高,NaOH用量3.5%时,白度最大上升了5.83%ISO,PC值降低了55.7%。这部分酚类物质易于生成颜色较深的共轭结构,是造成竹子SCMP难以漂白的一个重要原因。     

新闻纸厂胶粘物组分的分离与分析

对新闻纸厂网前筛筛板上的沉积胶粘物进行了分离与分析.结果表明,以聚醋酸乙烯酯和聚丙烯酸酯为代表的人工合成聚合物以及机械浆中的木材树脂是产生胶粘物的根本来源,但它们在胶粘物沉积中的含量只有约5%.胶粘物沉积中大部是无粘性的碳酸钙和细小纤维,说明碳酸钙等物质会与具有粘性的树脂类物质粘附在一起形成大量的沉积物.     

杨木APMP制浆废液化学成分的分析

对杨木APMP制浆废液的组分进行了定性和定量分析.结果表明,杨木APMP制浆废液的固含量为12.3％,废液的主要成分为半纤维素、木素、抽出物和无机物,其相对含量分别为54％、17％、14％和15％.杨木APMP制浆废液甲基叔丁基醚(MTBE)抽出物的气相液相质谱仪(GSMS)分析结果显示,抽出物中含有25种物质,其中小分子羟基酸和木素降解产物的含量分别为12％和50％.脂肪酸和甾醇是杨木APMP制浆废液亲脂性抽出物的主要成分,含量分别为29％和9％.     

POTATO EXTRACTIVES: EFFECT ON FIRMNESS OF PECTIN JELLIES AND VISCOSITY QF POTATO STARCH PASTES

SUMMARY— Pectin jellies and potato starch pastes were prepared with aqueous extracts of potato tissue. All jellies containing potato extractives were weaker than distilled water control jellies. Jellies containing extractives from bud tissue were weaker than those containing extractives from stem tissue. Extractives from tubers stored continuously at 38°F weakened the jellies to a greater extent than those from tubers stored at 38°F and conditioned for 1 wk. Jellies containing extractives from boiled tissue were weaker than those prepared with extractives from blanched or steamed tissue. The most viscous pastes were those made with distilled water. In every case, viscosity of pastes containing extractives from raw tissue was less than half that of distilled water pastes. When extractives from blanched, steamed or boiled tissue were used, the viscosity decreased still further. The rigidity of jellies and the viscosity of pastes prepared with deionized extracts were similar to those of jellies and pastes prepared with distilled water. The data suggest that extractives leached from potato tissue increase sloughing of potato tissue during cooking by weakening the pectic materials in the intercellular cement rather than by enhancing the swelling of starch in the cells.     

Allergenicity of crustacean extractives and its reduction by protease digestion

This study was undertaken to evaluate and reduce the allergenicity of crustacean extractives that are added to a variety of processed foods as seasonings. Tropomyosin, the major crustacean allergen, was detected in only one of the six kinds of crustacean extractives by SDS–PAGE and immunoblotting. However, all the extractives were shown to be considerably allergenic by inhibition ELISA using sera from crustacean-allergic patients. Analyses by gel filtration HPLC suggested that tropomyosin is mostly degraded to peptide fragments during manufacturing of the extractives but at least some of the fragments are still IgE-reactive. On digestion with proteases, the allergenicity of the extractives was almost completely lost. The effectiveness of protease digestion to reduce the allergenicity of tropomyosin was also confirmed in model experiments using the heated extracts from four species of crustaceans.     

The effects of acetylation on the extractives of Sitka Spruce (Picea sitchensis) and Larch (Larix leptoleptis) wood

The extractives of acetylated spruce and larch wood were investigated and compared with their respective control counterparts using Fourier transform infrared to determine the effects of acetylation on extractives. Significant differences were observed among the spectra of organic solvents extractives in the control and modified wood, but no such differences were found in water-soluble extracts. It is postulated that the relatively bulky extract substances resident in the gross capillary structure were modified during the acetylation of wood and subsequently recovered by organic solvents, but the hot water extractives were possibly sugars from hydrolysis of less ordered polysaccharides. The mechanism of extractives action during acetylation is that of a scavenger mopping up unreacted anhydride and by-product acetic acid.     

麦草碱法制浆原料组分对污染物贡献率的研究

研究了不同备料方式和制浆工艺条件下,麦草中的纤维素、半纤维素、木素、苯-醇抽出物和灰分的溶出规律,对原料组分与污染物之间的转化特征进行了量化研究,对比了备料方式对原料各主要组分转化的影响,导出原料各主要组分对污染物的贞献率.结果表明.原料各主要组分的降解物对黑液中有机物发生量的影响次序依次是:纤维素>木素>半纤维素>苯-醇抽出物.     

Wood adhesives fromPinus radiata bark

Conditions for extracting bark of radiata pine (Pinus radiata D. Don) were examined with the purpose of obtaining high yield and high quality extractives for wood adhesives. A four-stage squeeze extraction comprising a two-stage extraction with hot water and one-stage extraction with NaOH aqueous (pH 8.3) solution followed by a one-stage washing with hot water doubled the extractives yield obtained by the first two-stage hot water extraction alone and resulted in a total extractives yield of 30% from commercially available samples of the radiata pine bark. Furthermore, high purity of polyflavanoids in the extractives was obtained by the four-stage squeeze extraction and viscosity reduction was achieved by sulphitation of the insoluble fraction of the extractives. Subsequently, unfortified plywood adhesives of sufficiently high quality to satisfy the requirements for Type A bond (fully weather and boil proof) were readily formulated from the high yield extractives.     

Changes during growth in anatomical and chemical composition and in-vitro degradability of lucerne

Lucerne (alfalfa) was harvested at different stages of maturity and the plants classified according to a phenological scale. The main class was separated into anatomical parts and analysed for content of extractives and crude protein and in-vitro degradability. Whole crop samples were also analysed for polysaccharide residues, Klason lignin and in-vitro degradability of crude protein and polysaccharide residues. The composition of the plant changed during maturation with an increase of the stem fraction from 18.5% to 50.7% of dry matter and a corresponding decrease in the leaf fraction from 72.9% to 18.4% of dry matter. The leaf fraction changed least in content of extractives and crude protein and in-vitro degradability while in the stems all these paramaters decreased radically. Chemical analysis of residues after incubation with rumen liquor in vitro of whole crop samples revealed that the degradability of crude protein declined from about 90% to about 80% and of non-starch polysaccharides from about 90% to about 60% during maturation. Xylose was the least degradable polysaccharide residue at all harvests. Xylose residues also showed the greatest decrease in degradability during growth. A comparison showed that stage of development and harvest date were of practically equal value as predictor of crude protein content in lucerne.     

纳米活性炭对中药或植物活性成分的吸附与缓释研究进展

文章综述药物缓释制剂的作用和种类,评述纳米活性炭作为活性成分缓释载体的理化特性,归纳近年来国内外对纳米活性炭作为中药或植物活性成分缓释制剂载体的研究进展,指出纳米活性炭的制备以及纳米活性炭作为活性成分缓释制剂遇到的技术瓶颈和今后的研究方向。