阳离子聚合物/膨润土纳米复合吸附材料的性能及对红色染料的脱色

利用阳离子聚合物-聚环氧氯丙烷二甲胺为插层剂,采用 “有机高聚物溶液直接插层复合法”制备了一系列阳离子聚合物聚环氧氯丙烷二甲胺/膨润土纳米复合吸附材料,经特性分析表明,经聚环氧氯丙烷二甲胺插层复合后的膨润土比表面积显著增加,表面电性由负值变为正值,颗粒的聚集程度增加,有较好的吸附和沉降性能.在此基础上,研究了还原大红R、分散大红S-R、活性艳红K-2BP等红色染料在复合膨润土上的吸附行为.结果表明,聚环氧氯丙烷二甲胺/膨润土对三种染料的吸附脱色能力明显大于钠基膨润土,平衡吸附量q_e与平衡浓度C_e之间的关系均符合Langmuir和Freundlich等温吸附模型,吸附动力学行为遵循Langmuir方程所述规律.     

单体插入-层间聚合法合成聚环氧氯丙烷二甲胺/膨润土

以二甲胺、环氧氯丙烷、乙二胺和钠基膨润土为原料采用单体插入-层间聚合法制得了一系列聚环氧氯丙烷二甲胺/膨润土（EPI-DMA/Bt）,研究了二甲胺投加量、环氧氯丙烷和二甲胺的摩尔比、乙二胺投加百分比、反应温度、聚合时间等因素对制得的EPI-DMA/Bt吸附性能的影响,并对EPI-DMA/Bt的结构进行了XRD和比表面积表征。实验结果表明,当二甲胺投加量为膨润土阳离子交换容量的4倍（3 mmol·g^-1）,n(环氧氯丙烷/二甲胺)=1∶1,m［乙二胺/（环氧氯丙烷+二甲胺)］=2%,反应温度为65℃,聚合反应时间为3 h时,合成的EPI-DMA/Bt的聚合物负载量为100 mg·g^-1左右,对活性翠兰的脱色率达90%以上。     

EPI-DMA共聚物中交联剂结构与HPAM溶液降粘效果研究

以二甲胺、环氧氯丙烷为原料,合成出环氧氯丙烷—二甲胺(EPI-DMA)聚合物,并探索了反应温度、反应时间、投料比、交联剂种类和交联剂用量对产物性能的影响,确定了最佳反应条件。最佳工艺条件为:交联剂三乙烯四胺,其加入量为1.5%,n(环氧氯丙烷):n(二甲胺)=1.5:1,反应温度70℃,反应时间5h。在该工艺条件下,用0.2g聚合物对于200ml浓度为500ppm聚丙烯酰胺溶液降黏,在470nm波长可见光分光光度计下测量其降黏后吸光度为0.09,降黏效果最为明显。     

麦羟硅钠石/聚合物纳米复合材料研究进展

麦羟硅钠石（magadiite）是一种新型的层状纳米硅酸盐材料,由于其具有制备工艺简单、比表面积大、阳离子交换性能高、吸附性能强、层间膨胀性能好等优点,成为纳米材料提升聚合物性能最具有发展潜力的材料之一。本文主要综述了麦羟硅钠石/聚合物纳米复合材料的常用制备方法及其优缺点,包括聚合物插层法、单体原位插层聚合法、锚固插层聚合法。浅谈了国内外利用3种方法制备的基于聚苯乙烯、聚丙烯、环氧树脂、尼龙6、聚己内酯和聚甲基丙烯酸甲酯等多种聚合物的麦羟硅钠石/聚合物纳米复合材料,对在纳米复合材料结构中出现界面不相容、麦羟硅钠石分布不均匀的问题提出了解决方法,并阐述了麦羟硅钠石对纳米复合材料结构和性能的影响,最后展望了麦羟硅钠石/聚合物纳米复合材料的发展前景。     

聚合物/粘土纳米复合材料的研究进展

综述了聚合物/粘土纳米复合材料的制备、表征和性能。粘土经相容剂修饰成为有机土,层间距增大,层间微环境由亲水变为亲油,从而利于聚合物的插层。聚合物插层导致粘土片层剥离并分散于聚合物基体中,得到的聚合物/粘土纳米复合材料的机械和物理性能比原来的聚合物材料有了显著的提高。     

羧甲基纤维素钠/蒙脱土纳米复合材料的制备及结构表征

采用溶液插层法制备羧甲基纤维素钠/蒙脱土纳米复合材料,研究不同羧甲基纤维素钠溶液pH值、反应温度、反应时间和羧甲基纤维素钠与蒙脱土的质量比等因素对纳米复合材料有机化程度的影响。用X射线衍射、红外光谱、扫描电镜及透射电镜对样品进行结构表征,用热重分析对样品热性能进行分析。结果表明:羧甲基纤维素钠通过破坏蒙脱土的晶体结构插层进入到蒙脱土层间,形成插层–剥离型纳米复合材料;与羧甲基纤维素钠相比,纳米复合材料的热稳定性有了很大提高。     

小阳离子聚合物-聚乙二醇协同防膨作用研究

将实验室合成的一种环氧氯丙烷/二甲胺型小阳离子聚合物(PDE)与聚乙二醇(PEG)进行复配,通过钙基膨润土静态防膨率实验,证明体系具有协同防膨效果。结合显微观察,激光粒度分布测定和X-射线衍射实验分析得出以下结论:小阳离子聚合物PDE和PEG具有协同防膨效果;PDE-PEG体系可与膨润土颗粒形成体积较大的稳定的颗粒结构;PEG分子可插入蒙脱石晶层间进行吸附;而阳离子聚合物PDE分子没有进入蒙脱石晶层间,只在蒙脱石颗粒的表面发生吸附。     

表面活性剂在聚合物/蒙脱石纳米复合材料制备中的应用

简要叙述了蒙脱石的结构;综述了阳离子表面活性剂插层蒙脱石以形成有机蒙脱石的机理、插层方法以及阳离子表面活性剂的结构对被插层蒙脱石的层间距的影响;讨论了不同类型的聚合物/蒙脱石纳米复合材料制备方法;同时比较了所得到的纳米复合材料的力学性能、热性能与纯聚合物的力学性能和热性能。结果表明:前者的力学性能和热性能比后者均有较大程度的提高。最后提出了聚合物/蒙脱石纳米复合材料目前存在的问题、发展方向和应用前景等。     

阳离子聚合物粘土稳定剂的合成及性能研究

以二甲胺、环氧氯丙烷为原料,通过缩合聚合反应,合成了阳离子有机聚合物粘土稳定剂。考察了原料配比、反应温度、反应时间对防膨率的影响。结果表明,最佳合成工艺条件为:环氧氯丙烷与二甲胺的摩尔配比为1∶1.2,反应时间5 h,反应温度60℃。粘土稳定剂用量2.0%时,防膨率为87.5%;与KCl或NH4Cl以1∶1复配,用量为4%时,防膨率分别为94.9%,93.2%。粘土稳定剂用量2.0%时,第1次和第2次岩屑回收率分别为82.16%,79.49%;2%聚合物+1%KCl+1%NH4Cl三元复配,第1次和第2次回收率分别为89.66%,86.41%。     

皂石/聚合物纳米复合材料的制备研究进展

介绍了皂石/聚合物纳米复合材料主要的制备方法,即:溶液插层法、原位聚合法和熔融插层法,以及皂石在纳米复合材料中的作用。综述了制备方法、制备工艺条件对皂石/聚合物纳米复合材料性能的影响。分析了制备皂石/聚合物纳米复合材料现存的问题,对未来的研究进行了展望。     

Formation and characteristics of cationic-polymer/bentonite complexes as adsorbents for dyes

The adsorption of cationic polymer, i.e., epicholorohydrin-dimethylamine polyamine (EPI-DMA), on bentonite particles was investigated under various conditions of bulk polymer concentration, pH, inorganic salts, and temperature. The resulting high adsorption rate and alkaline solution (pH = 7–11) effect indicated a strong electrostatic interaction between the clay particles and EPI-DMA molecules. Addition of salt can also influence the adsorption of EPI-DMA onto bentonite by affecting the clay particle sizes, the polymer zeta potential and etc. The Freundlich and Langmuir isotherm models were employed and fit the experimental data well in the low EPI-DMA concentration range 0.5–5.0 mg L^− 1. The enthalpy implied by the temperature dependence of adsorption of EPI-DMA on bentonite is 7.93 kJ mol^− 1, suggesting that neither coordination exchange nor chemical bond forces exit in this system. In addition, at high temperatures, larger amounts of EPI-DMA were adsorbed by bentonite, which indicated that increased entropy in the dissolved EPI-DMA molecules contributes to adsorption. The X-ray diffraction (XRD) analysis showed that besides the EPI-DMA molecules intercalated between the layers of bentonite, excess polymer molecules were adsorbed onto polymer loops protruding from the surface of the complex. The TGA and corresponding DSC plots demonstrated that the EPI-DMA polymer had intercalated into the clay layers and thus the EPI-DMA/bentonite was more hydrophobic than natural bentonite. With the addition of EPI-DMA polymer, the negatively charged clay particles increased to a net positive charge and the capacity for dye removal also went up with increasing polymer contents in EPI-DMA/bentonite complexes.     

CPAM的合成及影响因素分析

以甲基丙烯酰氧乙基三甲基氯化铵(DMC)和丙烯酰胺(AM)为聚合单体,以亚硫酸氢钠和过硫酸铵为引发剂,通过水溶液聚合法聚合得到阳离子聚丙烯酰胺(CPAM)。考察了聚合单体的质量分数、引发剂的用量、反应时间、反应温度及p H等因素对聚合物相对分子质量的影响。实验结果表明,合成高相对分子质量的CPAM的较优聚合条件是:聚合单体的质量分数为15%,引发剂0.3%,反应温度80℃,p H值为7,反应时间为3 h,相对分子质量可达5.91×106。     

阳离子型超支化聚丙烯酰胺的合成与反应中影响产物黏度因素的探讨

以季戊四醇为支化剂,按一定的比例加入丙烯酰胺(AM)并加入阳离子单体甲基丙烯酰氧乙基三甲基氯化铵(DMC)增加其阳离子性,合成了具有阳离子性的超支化聚丙烯酰胺。对产物进行了红外光谱(FTIR)分析,并使用旋转粘度计和一定计算测得了聚合物的增比黏度。而后探讨了反应温度、反应时间和引发剂用量对产物粘度的影响。     

阳离子聚合物的制备与应用性能

以环氧氯丙烷、二甲胺为原料合成制备了一种阳离子高聚物,并测试了其对活性染料染色织物的固色性能和对印染废水的絮凝脱色性能,结果表明所制备的阳离子高聚物具有优异的固色性能和良好的絮凝脱色性能。     

Effect of physico-chemical conditions on the properties of zeolite microparticles used in pulp and paper applications

Zeolites are framework aluminosilicates that have been proposed as a replacement for bentonite in microparticle retention systems. It has been claimed in many patents that zeolite can improve sheet formation in fine paper manufacturing. However, this improvement was not observed in mechanical grades. These experimental results, and also theoretical evidence, suggest that papermaking pH plays an important role in zeolite efficiency. In consequence, the effect of pH and temperature on the chemical properties of zeolite and bentonite microparticles was determined. Streaming potential, conductivity, and pH were measured while microparticle solutions were gradually acidified to pH 5. Samples were also taken at specific pH values to measure the cationic demand. Results showed that a gradual reduction of pH caused several modifications to zeolites. The first step was the neutralization of free hydroxyl ions in solution. The second step was an irreversible exchange of the charge-compensating sodium ions by hydrogen ions on the inner and outer surface of microparticles. Finally, dealumination of the zeolites occurred. It was determined that neutralization must be completed before ion-exchange can begin. However, ion-exchange and dealumination occurred simultaneously. Between pH 7.5 and 9, zeolites had more anionic sites than bentonite (around 0.8 meq/g vs. 0.5 meq/g). The higher surface charge of zeolites might partly explain their efficiency in microparticle systems. On the other hand, under pH 7.5, the anionic charge of zeolite samples rapidly decreased while that of bentonite was stable. The effect of temperature was also studied in the 25 to 55 °C range. Generally, a temperature rise promoted a greater dissociation of the surface hydroxyl groups and an acceleration of ion-exchange and dealumination processes.     

丙烯酰氧乙基三甲基氯化铵-丙烯酰胺共聚物的制备研究

以丙烯酰氧乙基三甲基氯化铵(DAC)和丙烯酰胺(AM)为单体,过硫酸铵和亚硫酸氢钠为引发剂,采用水溶液聚合合成阳离子高分子聚合物P(DAC-AM)。讨论了单体质量比、引发剂用量、温度等因素对聚合反应的影响,得到了合适的制备参数:反应温度55℃,引发剂0.035g,单体质量比m(AM):m(DAC)=3:14;并对产物进行了红外光谱和热失重分析,确定了聚合物为P(DAC-AM),热分解温度为230℃。     

阳离子改性苯乙烯-马来酸酐共聚物的制备与表征及应用

以2,3-环氧丙基三甲基氯化铵(ETA)为阳离子化试剂,对苯乙烯-马来酸酐共聚物(SMA)进行阳离子化改性,制备出一种阳离子性高分子分散剂(SMG)。通过红外光谱、含氮量、表面张力以及溶解性等的测定,研究了SMG的结构与性质;通过对颜料黄14的分散性考察,研究了SMG的分散性能。结果表明,SMA在阳离子化过程中,酸酐基团全部开环,部分形成酯键,阳离子化度达到7.5%左右;SMG的表面活性较低,但对颜料黄14的分散稳定性较好,在pH=7.0条件下,可以使颜料的Zeta电位提高至 35.4 mV。     

酸白土催化体系开环八甲基环四硅氧烷的研究及机理探讨

Cationic ring opening polymerization of octamethylcyclotetrasiloxane （Da） initiated by acid treated bentonite was investigated. The experimental conditions were chosen on the basis of preliminary experiments.Higher temperature was found beneficial for the reaction process while stirring intensity beyond a certain level showed no obvious effect on the reaction rate. Polymers were characterized by Fourier transform infrared, proton nuclear magnetic resonance （IH-NMR） and gel perneation chromotography. The width of molecular mass distribution was found ranging between 1.2 and 1.4, which is extraordinarlly narrow compared with that of cationic polymerizations reported elsewhere （〉 1.9）. The results were believed due to the absence of free proton and counter ion which simplifies the polymerization process and the huge steric hindrance provided by bentonite particles which keeps the propagation of polysiloxane onto the surface of bentonite particles in a much more regular way. A feasible mechanism is proposed and seems to be supported well by experiments. Additionally, from the results of α, ω-dihydrogen terminated polysiloxanes prepared, the possibility of applying this potential environmentally friendly heterogeneous catalyst in industrial polymerization of cyclosiloxanes is anticipated.