凹凸棒石/羧甲基纤维素钠复合材料的制备及其吸附性能

以凹凸棒石(Attapulgite,AT)和羧甲基纤维素钠(Sodium carboxymethyl cellulose,CMC-Na)为原料,采用溶液共混法制备了凹凸棒石/羧甲基纤维素钠复合材料.探讨了凹凸棒石和羧甲基纤维素钠质量比对复合材料吸附盐酸四环素的影响,结果表明,当凹凸棒石与羧甲基纤维素钠质量比为3∶20时,复合材料的吸附性能最佳,吸附量为132.59 mg/g.并利用傅里叶红外光谱(FT-IR)、X射线衍射(XRD)、热重分析(TG)、扫描电子显微镜(SEM)和比表面积仪对复合材料进行了表征.考察了吸附时间、吸附温度和溶液pH值对复合材料吸附盐酸四环素的影响,研究了其吸附过程.结果 表明,当吸附温度为30℃、吸附时间为1.0h、pH值为3时,吸附能力较大,为157.55 mg/g,复合材料对盐酸四环素的吸附过程符合Langmuir吸附等温式和准二级动力学模型.     

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。     

聚烯烃/凹凸棒石纳米复合材料研究进展

文章在介绍凹凸棒石(ATP)的结构特点和提高ATP在聚烯烃复合材料分散性的几种基本技术基础上,重点对聚丙烯(PP)/凹凸棒石纳米复合材料的力学、结晶及加工性能等进行了综述.同时还介绍了低密度聚乙烯(LDPE)、乙烯-辛烯共聚物(EOC)/凹凸棒石(ATP)纳米复合材料的各方面性能.     

魔芋葡甘聚糖/凹凸棒石纳米复合材料的制备及性能

以江苏盱眙提纯凹凸棒石（attapulgite,AT）为原料,以魔芋葡甘聚糖（konjac glucmannan,KGM）为基体,采用共混法制备了KGM/AT纳米复合材料,探讨了凹凸棒石质量分数、KGM质量分数对纳米复合材料性能的影响。力学性能测试结果表明：当魔芋用量为0.50%、凹凸棒石用量为0.02%时,复合材料的综合力学性能最好,与纯魔芋膜相比,其拉伸强度、断裂伸长率和弹性模量分别提高54.95%、19.97%、10.79%。利用Fourier红外光谱、扫描电子显微镜对纳米复合材料进行了表征,结果表明：AT的引入,KGM分子某些特征峰的波数发生了明显变化,凹凸棒石与魔芋葡甘聚糖发生了强烈的相互作用形成了新的界面层,且AT在纳米复合材料中分散性较好。     

原位乳液聚合制备聚苯乙烯丁二烯橡胶/凹凸棒石纳米复合材料

采用原位乳液聚合制备了聚苯乙烯丁二烯橡胶(SBR)/凹凸棒石(AT)纳米复合材料。凹凸棒石的存在一定程度上降低了乳液聚合速率,但对最终聚合产物的分子质量及分子质量分布影响不大。凹凸棒石以长0.5～5μm、直径为20～50nm的棒状纤维均匀的分散在SBR基体中。在硫化过程中,凹凸棒石纤维与橡胶形成互穿网络结构,增加了橡胶的交联密度。随着凹凸棒石的填充量增加,纳米复合材料的300%定伸应力和拉伸强度与纯SBR相比均提高了20%～100%,其补强效果明显高于等量的炭黑N330,还表现出良好的耐磨性能。     

凹凸棒石/魔芋葡甘聚糖纳米复合材料的制备及性能

以江苏盱眙提纯凹凸棒石为原料,魔芋葡甘聚糖(KGM)为基体,采用共混法制备了凹凸棒石/魔芋葡甘聚糖纳米复合材料.利用傅立叶红外光谱(FTIR)和热重分析(TG)手段对材料进行了表征.力学性能测试结果表明,改性凹凸棒石适量的引入,能提高复合材料的力学性能.纳米复合材料制备的较佳条件为:季铵盐用量为凹凸棒石用量的12％,改性时间为120 min,改性温度为85℃,改性凹凸棒石的填充量为魔芋质量的0.04％,增塑剂甘油的用量为魔芋质量的0.09％.FTIR表明:增塑剂甘油的加入,并未影响复合材料的结构.复合材料的热稳定性高于KGM薄膜.     

聚乙烯/凹凸棒石纳米复合材料的研究

采用原位聚合法制备聚乙烯／凹凸棒石纳米复合材料,结果表明：凹凸棒石的纳米级晶须可在聚乙烯树脂中能够较好地分散,聚乙烯在凹凸棒石表面绞缠,并且在不同晶须间绞缠,形成独特的交联网状结构一“有机／无机凝胶”;纳米复合材料能够显著提高聚乙烯的抗冲强度。     

聚吡咯/凹凸棒石纳米复合材料的制备及导电性能

以三氯化铁(FeCl_3)为氧化剂,十二烷基磺酸钠(sodium dodecylsulfonate,DSNa)为掺杂剂,使吡咯单体(pyrrole,Py)在凹凸棒石(attapulgite,ATP)的表面发生原位聚合反应,制备出聚吡咯/凹凸棒石(polypyrrole/attapulgite,PPy/ATP)纳米导电复合材料.研究了毗咯用量、聚合温度、聚合时间、FeCl_3用量以及DSNa用量对纳米导电复合材料体积电阻率的影响,确定了制备纳米导电复合材料的工艺条件.通过X射线衍射、热重-差热分析、Fourier红外光谱、Raman光谱和透射电子显微镜对纳米复合材料进行表征,结果表明:当吡咯用量(以ATP的质量计)为30%,FeCl_3与Py的摩尔比为2.3,DSNa的浓度为0.02g/mL时,20℃反应3h得到的PPy/ATP复合材料的体积电阻率可达7Ω·cm,聚吡咯以非晶态形式存在于凹凸棒石表面,两者之间的作用为物理作用.     

凹凸棒石-银纳米复合抗菌材料制备方法和表征

凹凸棒石是具有链层状晶体结构镁铝硅酸盐粘土矿物,呈现直径约30～40nm、长度可达数微米的棒状晶体形态,是产出丰富的天然纳米矿物材料,表现出纳米效应、吸附活性和化学活性,是一种重要的载体材料.本文研究了凹凸棒石-Ag纳米复合抗菌材料制备方法和抗菌效果.高分辨透射电镜(HRTEM)表征结果表明:用丙胺基三乙基硅烷为表面活性剂,醌醇为还原剂,凹凸棒石硝酸银浸溃法制备的复合材料,纳米银颗粒为1～7nm,均匀分布在凹凸棒石表面,复合抗菌材料含银0.52%.抗菌圈实验显示较好的抗菌效果,悬浮液浊度法抗菌实验显示凹凸棒石-Ag纳米复合抗菌剂最低抗菌浓度为0.47g/L.     

蒙脱石和凹凸棒石纳米复合材料制备、表征和潜在应用

由于晶体结构的制约,蒙脱石和凹凸棒石具有不同的形态和物理化学性质,在水悬浮体系中必定存在蒙脱石和凹凸棒石的互相作用.但这种互相作用的形式和材料科学意义未曾被人认知.本文通过对蒙脱石样品化学剥片和对凹凸棒石样品的分散处理,悬浮液混合和蒙脱石-凹凸棒石颗粒之间的互相作用,实现凹凸棒石和蒙脱石矿物纳米复合,X射线粉末衍射分析、高分辨透射电镜以及比表面积分析证实这种互相作用的存在和颗粒之间的缔合形式.剥片后的蒙脱石纳米晶片和分散的凹凸棒石纳米纤维发生面-面互相作用.2种矿物复合的结果,使得固体产物产生特殊纳米孔结构.此种材料在催化剂制备、吸附脱色、废水废气处理等方面具有潜在的应用价值.     

Preparation of sodium carboxymethyl cellulose from paper sludge

BACKGROUND: This paper describes the reuse of paper sludge, an industrial solid waste, for the preparation of sodium carboxymethyl cellulose (CMC). The process includes pretreatment, basification and etherification. RESULTS: The optimal pretreatment condition involved the addition of 6.7% hydrochloric acid to the paper sludge for 30 min at 70 °C. The order of factors influencing the effect of reaction was: etherification temperature > sodium hydroxide dose > basification temperature > etherification time > sodium chloroacetate dose. The optimal preparation condition of CMC was: m_papersludge: m_{sodiumhydroxide}: m_{sodiumchloroacetate} = 0.9:0.8:1.15; basification at 40 °C; etherification at 60 °C for 1 h. Under these conditions, certified CMC with viscosity less than 20 mPa· s, DS more than 0.50 and purity more than 90% was produced. The results of Fourier transform infrared (FTIR) and X‐ray diffraction (XRD) spectra analyses indicated that the product has characteristics of high degree of substitution (DS) and low crystallinity. The coated paper using CMC prepared from paper sludge as a water retention agent can meet the quality standards of GB/T 10335.1‐2005. CONCLUSION: Preparation of CMC from paper sludge can be considered a feasible alternative, generating value‐added product and contributing to solving environmental problems resulting from paper sludge. Copyright © 2008 Society of Chemical Industry     

Preparation and characterization of sodium carboxymethyl cellulose from cotton stalk using microwave heating

BACKGROUND: This paper describes the use of cotton stalk, an agricultural waste, for the preparation of sodium carboxymethyl cellulose (CMC) using microwave heating. The study includes the optimization of pre‐treatment and preparation processes, and the characterization of product. RESULTS: The optimal cotton stalk pre‐treatment condition involved the addition of 12% alkali to extract cellulose for 6 min at a microwave power of 200 W using the ratio of cotton stalk to solvent 1:9, giving 87.52% cellulose. Response surface methodology was applied to optimize the preparation of CMC, with the best conditions for preparation predicted by the model: $m_{\rm {cotton stalk cellulose}}:m_{\rm {sodium hydroxide}}:m_{\rm {sodium chloroacetate}} = {1.0:1.1:1.2}$ with etherification at 195.5 W of microwave power for 1.97 min. Under these conditions, CMC with degree of substitution (DS) 0.77, viscosity 498.0 cps and purity 92% was produced. The results of Fourier transform infrared (FT‐IR) spectroscopy indicated that the product had the characteristics of a high DS. Scanning electron microscopy showed that the particles were nearly clava in shape with length ranging from about 12–100 µm. The product met the quality standards of GB/T1904‐2005. CONCLUSION: Preparation of CMC from cotton stalk using microwave heating can shorten the processing time and may be considered a feasible alternative, contributing to solving environmental problems resulting from cotton stalk. Copyright © 2011 Society of Chemical Industry     

羧甲基纤维素钠和羟乙基纤维素在日化产品中的应用

羧甲基纤维素钠(CMC)和羟乙基纤维素(HEC)是纤维素醚类产品中使用范围最广的产品,它们是纤维素链上葡萄酐单元的羟基与醚化基团(氯乙酸或环氧乙烷)反应而成的。其水溶液是非牛顿性流体,黏度随剪切速率变化而与时间无关。溶液的黏度随浓度增大迅速增加,是使用范围最广的增稠剂和流变助剂。介绍了CMC和HEC的分子结构、合成制备、溶液特性和在日化产品应用的配方。     

疏水改性羧甲基纤维素及其pH敏感水凝胶的研究

通过羧甲基纤维素钠( CMC -Na)与脂肪酰氯在正庚烷介质中酯化反应制备疏水改性羧甲基纤维素(Ln-CMC -Na),讨论了物料比、温度和时间对反应的影响,确定了适宜的反应条件.根据Ln-CMC -Na的水溶性,确定在脂肪酰氯与CMC -Na摩尔比为0.08时,分别用十、十二、十四、十六和十八酰氯制备出系列改性产品,并测定了其HLB值、表面张力和临界胶束浓度.以三氯化铝为交联剂,Ln-CMC -Na作配体制得pH敏感水凝胶.     

羧甲基纤维素钠复合纳滤膜的制备与性能表征

以羧甲基纤维素钠(CMC)为活性层铸膜液,聚砜(PSF)超滤膜为基膜,戊二醛(GA)水溶液为交联剂,采用涂敷和交联的方法制得一种新型荷负电复合纳滤(NF)膜。测定了复合膜的截留相对分子质量,并对其表面形貌进行了表征。在铸膜液中添加质量分数为3.5%的不同种类有机小分子,研究了其对复合膜截留性能的影响。CMC/PSF复合膜对几种无机盐的截留顺序为:Na2SO4>NaCl>MgSO4>MgCl2。     

Effect of attapulgite contents on release behaviors of a pH sensitive carboxymethyl cellulose‐g‐poly(acrylic acid)/attapulgite/sodium alginate composite hydrogel bead containing diclofenac

A series of pH‐sensitive composite hydrogel beads, carboxymethyl cellulose‐g‐poly(acrylic acid)/attapulgite/sodium alginate (CMC‐g‐PAA/APT/SA), were prepared by combining CMC‐g‐PAA/APT composite and SA, using Ca²⁺ as the ionic crosslinking agent and diclofenac sodium (DS) as the model drug. The effects of APT content and external pH on the swelling properties and release behaviors of DS from the composite hydrogel beads were investigated. The results showed that the composite hydrogel beads exhibited good pH‐sensitivity. Introducing 20% APT into CMC‐g‐PAA hydrogel could change the surface structure of the composite hydrogel beads, decrease the swelling ability, and relieve the burst release effect of DS. The drug cumulative release ratio of DS from the hydrogel beads in simulated gastric fluid was only 3.71% within 3 hour, but in simulated intestinal fluid about 50% for 3 hour, 85% for 12 hour, up to 90% after 24 hour. The obtained results indicated that the CMC‐g‐PAA/APT/SA hydrogel beads could be applied to the drug delivery system as drug carriers in the intestinal tract. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011     

木浆制备钻井液用低黏羧甲基纤维素钠盐

低黏羧甲基纤维素钠盐是一种优异的降滤失剂,国内大多以精制棉为原料、选用溶媒法工艺生产该产品。本文选用造纸木浆为原料,采用工艺简单的水媒法制备钻井液用低黏羧甲基纤维素钠盐。通过纤维浆的优选、醚化剂制备工艺的确定、设计取代度的确定、水量的确定以及降解剂用量的确定,进行工艺条件调整,最终确定了产品的配方。     

HCl和TSA共掺杂聚苯胺/凹土纳米导电复合材料

用快速原位聚合工艺制备了盐酸(HCl)和对甲苯磺酸(TSA)共掺杂聚苯胺(PANI)/凹土(ATP)纳米复合材料.通过正交实验确定了最佳反应条件,并用紫外-可见光谱、热重-差热分析、X射线衍射、Fourier红外光谱、透射电镜等对最佳条件下所得的纳米复合材料进行了表征.结果表明:HCl和TSA的混酸环境能快速实现苯胺的聚合及聚苯胺的掺杂,所生成的聚苯胺以晶态形式包覆在凹土的表面,并在物理作用下与凹土形成了纳米核壳结构纳米复合材料;纳米复合材料中聚苯胺的包覆率为23.49%,与纯HCl和TSA共掺杂聚苯胺相比,纳米复合材料的耐热性能得到提高.     

农作物秸杆制备羧甲基纤维素工艺的研究

本文以玉米秸秆为原料,讨论了制备羧甲基纤维素的工艺。它的最佳条件为;NaOH用量为8g,碱化温度30℃～35℃,碱化时间50min;醚化剂(一氯乙酸)用量为11g,醚化时间120min,醚化温度65℃;乙醇质量分数75%,其产品质量符合纺织行业上浆标准。     

On the low frequency dielectric behavior of carboxymethyl cellulose and its sodium salt

A dielectric dispersion and frequency loss peak within the low frequency range 0.05–1 kc/s and at temperatures of 283–333 K was observed in the case of the sodium salt of carboxymethyl cellulose and absent in the case of its acid form. The critical frequency of the dielectric absorption was independent of molecular weight and of the presence of low moisture content. The results obtained show that the variation with temperature of the dielectric constant is exponential at low frequency only in the case of the sodium salt of carboxymethyl cellulose. The significance of the results is discussed.