兴安落叶松木材半纤维素中各种糖类组分的薄层色谱测定

作者以兴安落叶松(Larix dahurica Turcz.)为研究对象,采用薄层色谱分离、双波长扫描等技术手段,定量测定了兴安落叶松原木不同部位的半纤维素中糖类组分。落叶松苯-醇抽提物含量,心材较边材为高,综纤维得率边材比心材高。落叶松原木半纤     

落叶松木素对落叶松磺化化机浆（SCMP）磺化过程的影响

本文用扫描电镜－能谱（ＳＥＭ－ＥＤＸＡ）~（１３）Ｃ－ＮＭＲ、ＩＲ对落叶松磺化过程中细胞壁各层木素磺化反应活性，磺化化学机械浆（ＳＣＭＰ）中残余木素化学结构特性进行了研究。并对落叶松材磺化选择性和残余木素结构变化及对成浆白度的影响进行了探讨。     

落叶松木素对落叶松磺化化机浆（SCMP）磺化过程的影响

本文用扫描电镜－能谱（ＳＥＭ－ＥＤＸＡ）和＾１＾３Ｃ－ＮＭＲ，ＩＲ对落叶松磺化过程中细胞壁各层木素磺化反应活性，磺化化学机械浆（ＳＣＭＰ）中残余木素化学结构特性进行了研究。并对落叶松材磺化选择和残余木素结构变化及对成浆白度的影响进行了探讨。     

Williamson反应合成二乙二醇二甲醚及其合成条件优化

以二乙二醇单甲醚（C5H12O3）和氯甲烷为原料,氢氧化钠为催化剂,在n（NaOH）：n（C5H12O3）=1．4：1．0（mol／mol）,减压条件下,先合成二乙二醇单甲醚醇钠盐,然后通入CH3Cl与二乙二醇单甲醚钠盐进行Williamson反应合成二乙二醇二甲醚（DMDE）。用正交实验法对二乙二醇二甲醚的合成条件进行了优化,气相色谱法分析了产品中DMDE的含量．用FT—IR和NMR分析测试手段表征了产物结构。实验结果表明该反应的最优工艺条件为：n（NaOH）／n（C5H12O3）／n（CH3Cl）=1．4：1．0：1．4,反应温度为90℃,CH3Cl通入时间为4．oh,二乙二醇二甲醚的收率可达95．0％以上。     

聚乳酸/改性刨花板木粉木塑复合材料的力学性能研究

采用氢氧化钠(NaOH)、过氧化氢（H2O2）、异氰酸酯(IPDI)等不同改性剂对刨花板木粉进行化学改性处理,将改性后的刨花板木粉（PBF）与聚乳酸(PLA)基体通过熔融挤出共混,制备出PLA/PBF 木塑复合材料,研究了刨花板木粉改性处理方法和含量对木塑复合材料力学性能的影响。结果表明,刨花板木粉经NaOH+H2O2或NaOH+IPDI处理后,能显著改善木粉与基体间的界面相容性,提高木塑复合材料的力学性能;经NaOH+H2O2处理后,PBF含量为20 %（质量分数,下同）的PLA /PBF木塑复合材料的弯曲强度相比于未处理的增加了21.63 %,达到118.5 MPa;拉伸强度增加了19.53 %,达到101.0 MPa;采用NaOH+H2O2改性处理的、PBF含量为20 %的PLA/PBF木塑复合材料具有更好的力学性能。     

含硫聚合物、单体，生产及它们的使用

用作去污增洁剂、水处理剂、颜料分散剂,纤维涂饰剂、或漂白组成物的该聚合物具有CH2C（R^1）R^2OCH2CH（OH）CH2X^1R^3的结构单元（X^1-S,SO2;R^1=H,Me;R^2=CH2,CO：R^3=C1-10有机基团）。该单体H2C：C（R^6）R^7OCH2CH（OH）CH2X^2R^8（X^2=S,SO2：R^6：H,Me;R^7=CH2,CO;R^8=C1-10有机基团）通过使H2C：C（R^11）R垃OG（R^11=H,Me：R^12=CH2,G=缩水甘油基）与SH化合物反应制备而成。228．3g的烯丙基缩水甘油酯用156．3g的巯基乙醇在水中处理,进而用H2O2处理单体,269．1g单体与126．0g80％的丙烯酸在有莫尔盐、NaOH、过硫酸钠和NaHSO3存在的水中聚合,生成的聚合物的Mw为8300,具有良好的粘泥分散性,和防止再污染能力。     

有机-无机溶剂连续抽提巨龙竹木质素及其结构表征

为了分析巨龙竹木质素的结构特征,采用有机-无机溶剂连续抽提的方式将木质素和半纤维素进行分离,脱蜡竹粉依次用80%二氧六环、80%二氧六环-0.5% NaOH、2% NaOH、5% NaOH和8% NaOH连续抽提后,得5个木质素样品L₁~L₅,计算了木质素得率,并对抽提所得的木质素样品进行了红外光谱(FT-IR)、紫外光谱(UV)、核磁共振碳谱(¹³C NMR)和二维核磁共振(2D HSQC)分析。结果表明:在二氧六环和不同浓度碱性水溶液的连续抽提下,最终从巨龙竹原料中分离得到70.6%的原本木质素,其中木质素样品L₂的纯度最高,表明该方法是一种较为有效的竹材木质素组分分离方法。木质素的苯环骨架结构在分离过程中没有被破坏,但碱浓度的增加导致木质素中部分酯键发生断裂。巨龙竹木质素大分子主要由愈创木基单元(G)、紫丁香基单元(S)、对羟基苯基单元(H)组成,木质素大分子基本单元之间的联接键主要是β-O-4'醚键,除此之外还有β-β'、β-5'和β-1'联接。     

大豆种皮过氧化物酶在木素降解与苯酚聚合中的应用

以大豆种皮过氧化物酶（Soybesnhullperoxidase，SHP，E．C．1.111．7）替代水煮过氧化物酶（LigninperoxidaseLiP）和锰过氧化物酶（Manganese－dependentperoxidase，MnP），以工业木素（木素磺酸盐和黑液木素）及天然木素（杉木木素）为材料，研究了SHP在正常催化条件下对木素的氧化作用。结果表明，SHP在水相系统中对工业木素和天然木素虽无降解作用，但在微水有机相中SHP对天然木素有部分解聚作用。利用SHP在水相体系中催化的酚聚合反应对含酚废水进行处理，则发现水相中SHP稳定性好，lmol／L的SHP和lmnlol／L的H202在15mitt内对终浓度为lmmol／L宋酚溶液的酚去除率达98％以上，提示SHP作为一种较理想的氧化还原酶用于含酚废水处理值得深入研究。     

钼砷酸／喹啉／聚合物膜的制备及光致变色性研究

将Dawson结构的18-钼砷酸（As2Mo18）与喹啉形成的电荷转移盐分别与聚乙烯醇（PVA）和聚乙烯吡咯烷酮（PVP）进行薄膜组装,得到具有可逆光致变色性的H6As2Mo18O62·9C9H7N·1．5C2H6O／PVA和H6As2Mo18O62＋9C9H7N·1．5C2H6O／PVP杂化薄膜,通过热重、IR、紫外-可见吸收光谱、循环伏安对杂化薄膜进行了表征,并对其光致变色性进行了研究。结果表明,光照后杂多酸与聚合物之间发生了电荷转移,杂多阴离子中的Mo^Ⅵ被还原为Mo^Ⅴ,同时聚合物被氧化。     

霉菌在含Cu^2＋废水处理中的试验研究

采用Fenton试剂法对化学需氧量（CODCr）为1000-2000mg／L,pH值为3-9的丁苯橡胶废水进行处理。在Fe^2＋／H2O2（体积比）为9／8,初始废水pH值为3．0-0．15,反应温度为50℃,反应时间为30min的条件下,研究了Fe^3＋,H2PO^-4,     

Structural characteristics of different softwood lignins according to 1D and 2D NMR spectroscopy

Abstract

Along with cellulose, lignin is one of the most common polymers of plant origin. Numerous studies show that the complex and irregular structure of lignin is still unknown. First of all, the existing problems are connected with the peculiarities of lignins as a natural chemical compound. In this paper the general regularities of the chemical structure of dioxane lignins isolated from the softwood – larch (Lárix sibírica), pine (Pinus cembra) and juniper (Juníperus commúnis). The studies were carried out using a combination of ¹³C, ³¹P and 2D NMR spectroscopy. According to HSQC spectra it was established that the main structural fragments are the structures of β-aryl ether, followed by phenylcoumarans, with lower amounts of other substructures. Signals belonging to a methyl substituted phenylcoumaron were first identified on the NMR spectra of softwood dioxane lignins. Signals related to the structure of 3′-O-methylated dihydroquercetin were found in the composition of larch dioxane lignin.     

Physicochemical characterization of lignin recovered from microwave‐assisted delignified lignocellulosic biomass for use in biobased materials

Lignocellulosic biomass (Moso Bamboo, Chinese tallow tree wood, switchgrass, and pine wood) was subjected to a novel delignification process using microwave energy in a binary glycerol/methanol solvent. The physicochemical properties of the recovered lignin were analyzed prior to its application in the fabrication of polylactic acid (PLA)–lignin composites. The results showed that the samples had a high Klason lignin content (>75%) and retained their natural structure. Thermogravimetric analysis revealed that the recovered lignin exhibited a different thermal decomposition pattern from that of commercial lignins. All the recovered lignins had good solubility in common organic solvents (acetone, 1,4‐dioxane, THF, DMSO, and ethanol/water) and 1 mol/L NaOH solution. The addition of lignin into the PLA matrix resulted in the improvement in tensile properties of PLA–lignin composites. PLA films with low lignin content had good UV light‐resistant properties, indicating that the recovered lignin has potential in packaging of light‐sensitive products. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 42635.     

Lignin and Other Aromatic Substances Released from Spruce Wood During Pressurized Hot-Water Extraction,Part 2: Structural Characterization

Extraction of ground spruce sapwood with pressurized hot water in an accelerated solvent extractor (ASE) at 170°C during 20, 60, and 100 min resulted in isolation of galactoglucomannans and aromatic substances, including lignin. The isolated lignin preparations were characterized by spectrometric (UV, FT-IR, ¹H NMR, liquid and solid-state ¹³C NMR), chromatographic (RP-HPLC, HP-SEC, GC-FID, and GC-MS), conventional pyrolysis, thermally assisted hydrolysis, and methylation techniques in tandem with GC-MS, and classical wet chemistry (methoxyl groups, total and phenolic hydroxyl groups, derivatization followed by reductive cleavage—DFRC). The content of β-O-4 bonds in isolated lignins was similar to that in MWL and their proportion decreased with extraction time. The oxidation of isolated lignins and content of total hydroxyl groups were significantly increased with extraction time. The lignin structure underwent condensation and demethylation reactions during hot-water extraction. The induction of new phenylcoumaran substructures was proposed in isolated lignins.     

阔叶木碱法造纸黑液提取物成分的研究

应用裂解-气相色谱-质谱、红外色谱、凝胶色谱、元素分析仪研究了阔叶木碱法造纸黑液提取物的成分.结果表明:黑液中含有木质素、有机酸等物质.其中,阔叶木木质素属愈创木-紫丁香(GS)型木质素,木质素分子中存在少量的α-β碳碳双键,紫丁香基结构单元的质量分数高于愈创木基结构单元,二者质量分数比为2.27;木质素的结构经验式为...     

木素表面活性剂的开发与应用

以工业木素为原料，可开发出多种表面活性剂产品，如染料分散剂、混凝土减水剂和加气剂、沥青乳化剂、表面活性剂采油的牺牲剂和原油乳化阵粘剂、液态燃料乳化剂等。木素表面活性剂价格低廉，有较强竞争力，开发木案表面活性剂有利于充分利用木素资源和治理纸厂制浆黑液造成的环境污染，应当加强这方面的研究工作，特别是基础研究。     

Fractionation of Lignocellulosic Materials for the Biorefinery: Separation and Characterization of Lignin from Calamagrostis angustifolia Kom

Dewaxed Calamagrostis angustifolia Kom was pretreated with hot water at 60 and 90°C for 3 h, and then the residue obtained was successively treated with 70% ethanol, and 70% ethanol containing 0.2%, 1.0%, 2.0%, 4.0%, and 8.0% NaOH at 80°C for 3 h. The dissolved components were subjected to further separation to get eight lignin fractions, which were characterized by gel permeation chromatography, Fourier transform infrared, and sugar analysis. All the lignin fractions had small weight-average molecular weights between 810 and 2580 g/mol. Two typical lignins, L₃ (prepared with 70% ethanol) and L₅ (prepared with 70% ethanol containing 1.0% NaOH), were further analyzed using ¹H, ¹³C NMR and HSQC spectroscopy. Signals from guaiacyl (G), syringyl (S), and p-hydroxyphenyl (H) units observed in aromatic/olefinic region of HSQC spectra indicated that the lignin from Calamagrostis angustifolia Kom could be classified as “GSH” lignin. In aliphatic-oxygenated region, β-O-4′ together with small amounts of β-5′, β-β′, and p-hydroxycinnamyl alcohol end group were the main interunit linkages observed. Aqueous ethanol, which could avoid the cleavage of ether bonds in lignin at neutral condition, was more effective than water on lignin extraction.     

Rapid Hydrothermolysis of Poplar Wood: Comparison of Sapwood,Heartwood, Bark,and Isolated Lignin

Abstract

Rapid hydrothermolysis at 350°C of poplar sapwood, heartwood and bark, as well as the lignin extracted from the sapwood and heartwood, gives oil and water soluble fractions whose chemical analysis is correlated with the nature of the feed stock. Results from cellulose and Douglas fir are included, and the poplar bark and heartwood lignin are shown to give an ether soluble oil that consists mainly of guaiacyl units while the sapwood product is mainly syringyl. However, the chloroform soluble oil from both sapwood and heartwood was mainly syringyl with the additional presence of carbohydrate derived material in the heartwood oil. The acetone-only soluble residue from sapwood was shown by pyrolysis mass spectrometry to be mainly cellulose derived while that from heartwood was mainly from lignin. Thus there is a fundamental difference in the behaviour of the poplar sapwood and heartwood that may arise from different distributions of the guaiacyl and syringyl units, and of the binding to the cellulose. The origin of the rapid hydrothermolysis products with respect to the major wood components is discussed. An empirical approach to the calculation of the lignin content based on the rapid hydrothermolysis fractions is presented.     

The methanogenic toxicity of wastewater lignins and lignin related compounds

Lignin derivatives are major components of wastewater streams generated in the chemical processing of wood. The objective of this study was to evaluate the inhibitory effect of various lignins isolated from forest industry wastewaters, and selected lignin model compounds, on methanogenic bacteria. The methanogenic inhibition was determined at 30°C in standard toxicity assays, utilizing anaerobic granular sludge as inoculum. The wastewater lignins differed considerably in their inhibitory activity. Some lignin samples were nontoxic, whereas others caused 50% inhibition at concentrations ranging from 3320 to 5950 mg COD dm^?3. Experiments with ultrafiltered lignins revealed that the toxicity of the inhibitory lignin samples originated from the low molecular weight fraction. In additional studies with low molecular weight lignin model compounds, it was observed that the inhibitory activity of these compounds was related to the functional groups on the aromatic ring. Compounds with aldehyde groups or apolar substituents were highly toxic, whereas those with carboxylic groups only caused significant inhibition at high concentrations. These results indicate that low molecular weight lignin derivatives in forest industry wastewaters are potential inhibitors of anaerobic treatment systems.