水解对SL-g-P(AA-AM)/PVP半互穿高吸水树脂结构与性能的影响

以木质素磺酸钠(SL)、丙烯酸(AA)、丙烯酰胺(AM)和聚乙烯吡咯烷酮(PVP)为原料,过硫酸钾(KPS)为引发剂,N, N′-亚甲基双丙烯酰胺(MBA)为交联剂合成了SL-g-P(AA-AM)/PVP半互穿网络高吸水树脂。将SL-g-P(AA-AM)/PVP在NaOH溶液中进一步水解得到H-SL-g-P(AA-AM)/PVP。通过单因素优化实验考察了水解时间、水解浓度、水解温度以及搅拌速率对树脂吸水倍率的影响。利用FTIR、LNMR、XRD、TG和SEM对水解前后样品的结构、热稳定性和表面形貌进行了研究；测试了水解前后样品的溶胀性能、保水性能及重复使用性能。结果表明,在NaOH浓度为0.0125 mol/L,水解温度为75 °C,搅拌速率为400 r/min的条件下水解2 h得到的树脂吸水倍率可达2011.12 g/g,远高于未水解树脂的吸水倍率(1292.11 g/g),且水解前后树脂的溶胀行为均符合一阶与二阶溶胀动力学模型。H-SL-g-P(AA-AM)/PVP在质量分数为0.9%的NaCl溶液中的溶胀能力(123.65 g/g)高于SL-g-P(AA-AM)/PVP(97.41 g/g),但由于水解后-COO_^-增多,树脂在MgCl₂和FeCl₃溶液中的溶胀能力并未提升,且H-SL-g-P(AA-AM)/PVP的溶胀能力受溶液pH影响较大。此外,水解后树脂的保水性能优于未水解的树脂,且具有一定的重复使用性能。     

MAH增容聚苯乙烯／木质素磺酸钙复合体系研究

以马来酸酐（MAH）为增容剂，研究了其对聚苯乙烯／木质素磺酸钙复合体系的影响。结果表明，MAH的加入使得复合体系的最大扭矩（Nm）降低，平衡扭矩（Nb）和蝗化时间（T）增加，其中Nm的降低幅度达到63．7％，而Nb和T分别增加了35．7％和190％。复合体系断面的扫描电子显微镜照片表明，MAH在添加量为5％（质量分数，下同）时，复合体系两相间形成了一定的过渡层，具有良好的相容性；复合体系的红外分析表明，两者在增容剂MAH的作用下发生了部分氢键的缔合，增加了两者的相容性。     

复合聚电解质凝胶的制备与性能研究 Ⅱ.聚丙烯酰胺/木质素磺酸钙凝胶的溶胀行为

采用电导和称重两种方法研究了聚丙烯酰胺/木质素磺酸钙凝胶的溶胀行为及温度和pH的影响。与单一聚丙烯酰胺凝胶在相同条件下的溶胀行为比较表明:在一定温度范围内,温度高有利于聚丙烯酰胺/木质素磺酸钙凝胶的溶胀,尤其是高于35℃后更加明显。同时磺化木质素具有在酸性条件下助溶胀和在碱性条件下抑制溶胀的作用,其中pH 11是聚丙烯酰胺/木质素磺酸钙凝胶在酸碱溶液中溶胀的一个临界值。     

Research Interfacial Properties of the Novel Lignosulfonates

Abstract

The interfacial tensions between the crude oil and the novel modified lignosulfonate solutions were measured by a spinning drop interfacial tension apparatus. Some effects that influence on IFT were discussed. With the increase of alkyl chain length or the number of lipophilic groups introduced, the interfacial activity of the modified lignosulfonate increases, and the optimum surfactant concentration required to reach ultra-low IFT decreases. Excellent activity at the interface of crude oil and the solutions was observed. The interfacial tensions of the modified lignosulfonates could be ultra-low over a wide range of surfactant concentration and alkali concentration without the addition of other surfactants. They are capable of being the principal surfactant in enhanced oil recovery (EOR).     

木质素磺酸钙热行为初步研究

采用差示扫描量热分析 (DSC)、热重分析 (TG)和升温红外光谱研究木质素磺酸钙的热行为 ,发现在室温到 40 0℃的范围内 ,木质素磺酸钙有三个主要的转变。第一个转变发生在较低温度范围内 ,可能与木质素磺酸钙的脱水和甲醛等小分子的反应相关 ;第二个转变的转变峰顶温度在 30 0℃附近 ,与木质素的高温缩合反应相关 ;第三个转变为热分解反应 ,与第二个转变紧密相接。文章认为 ,由木质素磺酸钙的升温DSC曲线可以大致了解其热历史     

In bed and downstream hot gas desulphurization during solid fuel gasification: A review

Syngas produced by gasification process of biomass fuels is an environmental friendly alternative to conventional petrochemical fuels for the production of electricity, hydrogen, synthetic transportation biofuels and other chemicals. However, the advanced utilization of syngas is significantly limited due to the contaminants which can seriously deactivate the catalysts used for downstream reaction such as steam reforming methane, Fischer-Tropsch synthesis and corrosion of downstream equipments such as a gas turbine. Among the contaminants, sulphur compounds produced in the gasification process, which are mainly H₂S with small amounts of COS, CS₂ and thiophenes depending on process conditions, must be removed. For biomass feedstock advances are required in the cleanup technologies and processes to upgrade the raw product gas with minimal impact on the overall process efficiency. Hot gas desulphurization (HGD) can improve the overall thermal efficiency due to the elimination of fuel gas cooling and associated heat exchangers. With this aim, the present review paper highlights currently developed methods used for desulphurization of hot gas produced from gasification process of solid fuels. The methods presented here are for both in situ and downstream sulphur capture. Also, the attention is paid to the regeneration of the used materials. In situ sulphur capture is mainly done by using calcium-based sorbents such as limestone and dolomite, whereas downstream sulphur capture is mainly focused on the use of regenerable single, mixed, and supported metal oxides. A comparison is indicated at the end to show the sulphur loading of various materials.     

LS-g-PAMPS/AA高吸水性树脂的微波合成及吸水性能

以木质素磺酸钠(LS-Na)、2-丙烯酰胺基-2-甲基丙磺酸(AMPS)、丙烯酸(AA)为原料,采用微波辐射法,通过接枝共聚合成LS-g-PAMPS/AA高吸水性树脂。探讨了微波功率、辐射时间对树脂吸水倍率的影响,研究了树脂在各种pH溶液中的溶胀行为,探讨了树脂的吸水速率、保水和反复吸水性能。结果表明,引入适量的LS-Na可以显著提高树脂的吸水速率、保水和反复吸水性能。树脂具有pH敏感性,在pH值4~12之间保持较高的吸水倍率,在pH值2与7的溶液里有良好的可逆行为。     

木质素磺酸钠的超滤级分对质量分数40%腈菌唑WP性能的影响

通过超滤将石岘木质素磺酸钠(简称木钠)分成5个相对分子质量(以下简称分子量)范围的级分。凝胶色谱和电位滴定测试表明,随着截留分子量由小变大,木钠超滤级分相对分子质量依次增大,重均分子量从2360增加到19852;磺化度依次减小,从2.66mmol/g降低到0.98mmol/g。以木钠超滤的5个级分为分散剂制备质量分数为40%的腈菌唑可湿性粉剂(WP)并测试其性能。结果表明,Fraction4(30000～50000)作分散剂制备的WP性能最优,热贮前后的悬浮率分别为85.36%和81.38%,悬浮液中分散相的平均粒径分别为6.30μm和9.19μm,热贮后WP悬浮液2h的沉淀层厚度及分散稳定指数分别为0.311mm和3.85。     

蔗渣木质素磺酸镁的结构特征及表面物化性能

通过紫外、红外光谱、核磁共振和电位滴定等方法研究了蔗渣木质素磺酸镁(MLS)的结构特征和表面物化性能,并与杨木木质素磺酸钙(CLS)进行了对比。与CLS相比,MLS含有较多量的紫丁香基结构和较少的愈创木基结构;MLS的重均分子量、磺酸基和酚羟基含量较低。采用超滤法将MLS分离成不同分子量的级份,发现随着分子量的提高,MLS中的3种基本结构单元的含量均一化,磺酸基与酚羟基含量增加,羧基含量减少。表面物化性能测试结果表明,分子量、磺酸根和酚羟基是影响MLS在水泥颗粒表面吸附及表面电位的主要因素。随着分子量的增加,MLS使水泥颗粒表面电位显著增加,截留分子量大于50000的MLS可使水泥颗粒表面的Zeta电位绝对值达到14.6mV,饱和吸附量达到6.0mg.g-1,吸附等温线近似为Langmuir型,与CLS相似。