聚丙烯腈/蒙脱土纳米复合材料的制备与表征

采用不同改性蒙脱土与丙烯腈单体原位聚合制得纳米复合材料,通过红外、XRD表征蒙脱土插层前后结构的变化,并用热重、差热分析产物的稳定性.X射线粉末衍射结果显示,改性后蒙脱土层间距被不同程度扩大,尤其是PAN/Na-MMT的(001)衍射峰已完全弥散,说明蒙脱土被剥离.差热、热重分析结果显示聚丙烯腈/蒙脱土纳米复合材料的热稳定性比纯聚丙烯腈有较大提高.     

季铵盐改性蒙脱石的超结构及其抗菌性能

为研究季铵盐改性对蒙脱石的结构及抗菌性能的影响,分别采用十八烷基三甲基氯化铵（OTAC）和双十八烷基二甲基氯化铵（DODAC）对蒙脱石进行插层改性,并分析了蒙脱石的d001层间距及抗菌性能随季铵盐用量变化的规律.蒙脱石的d001层间距先随季铵盐用量的增加而增大;当OTAC与蒙脱石的质量比超过35%或DODAC与蒙脱石的质量比超过15%时,其d001层间距开始略微下降,同时出现季铵盐以不同倾斜角排列的层间超结构现象.在水分散体系中,改性蒙脱石的抗菌性能先随季铵盐用量的增大而上升;当其出现超结构后,由于蒙脱石及季铵盐与细菌的接触几率受到限制,其抗菌性能开始急剧下降.在干燥条件下超结构对蒙脱石的抗菌性能影响甚微,经不同用量季铵盐改性的蒙脱石都具有极佳的抗霉菌性能.     

聚丙烯/聚丙烯接枝丙烯酸/蒙脱土纳米复合材料的制备及性能

用悬浮接枝法制备了接枝率为2 2%的聚丙烯接枝丙烯酸作为相容剂,用十六烷基三甲基溴化铵对钠基蒙脱土进行了有机化处理,使蒙脱土的层间距从1 2nm增加到了3 84nm。通过熔融插层法制备了插层型聚丙烯/蒙脱土纳米复合材料(Polypropylene/MontmorilloniteNanocomposites,PNC),复合材料中蒙脱土层间距比有机蒙脱土的层间距又有小幅度的增加。当蒙脱土含量为2%,相容剂用量为15%时的复合材料力学性能最好,缺口冲击强度和拉伸强度分别达到12 12kJ/m2和35 77MPa,分别比纯1PP增加了180%和4 3%,蒙脱土的加入起到了增韧和增强的双重作用。     

Preparation and characterization of polylactide/montmorillonite nanocomposites

The montmorillonite, a form of layered silicate, was successfully intercalated into polylactide (PLA) matrix through solvent-casting technique. In addition, PLA/MMT nanocomposite films were produced, in which homogenous distribution of the silicate lamellae plays a key role in the mechanical properties of the films. A small amount(5wt%) of OMMT intercalated into the PLA matrix resulted in their flexibility enhancement, from 3.68%(pure PLA film) to 352.65%. The results of wide-angle X-ray diffraction (WAXD) patterns confirmed that the silicate interlayer distance increased from 3.044 nm (for OMMT) to 3.56nm (for 5wt%, maximum) with increasing OMMT contents, but decreased to 3.319 nm when OMMT content was over 8wt%. FT-IR also verified the molecular-level associations between PLA chains and OMMT lamellae by vibration variances of hydrogen bonding. DSC thermograms demonstrated that thermal stabilities of the nanocomposite films enhanced, due to the silicate lamellae dispersed into PLA matrix.     

Preparation and Properties of Pillared Montmorillonite by Polyhydroxyl-aluminum-manganese Cations

Al-Mn-pillared montmoriUonite ( AMPM ) was prepared by using the artificial Na-montmoril-lonite from the Qingfengshan bentonite mine as starting materials mixed with Al-Mn pillaring solutions at different Al / Mn molar ratios ( R ). The basal spacing and specific surface area of the materials were increased significantly compared with untreated c/ays. When R=0.5, the d(001) value and specific surface area of pillared montmoril-lonite were 1.8987 nm and 146.01 m^2 g^-1, respectively. The thermal stability was determined using calcined tests,X-ray diffraction( XRD ) analysis, thermal gravimetry and differential thermal analysis( TG- DTA ). The formed at initial R = 0. 5 exhibited a high stability, the basal interlayer spacing was stabilized at 1. 7859 nm after calcined for 2 h at 300℃. The adsorption behavior of the materials wets studied by adsorption experi-ments. The results show the AMPM and calcined AI-Mn-pilloTed montmoriUonite (CAMPM) exhibit a strong ca-pacity of adsorbing the Zn ( Ⅱ ) in aqueous solution at pH 10.0.     

双酚A型苯并噁嗪树脂/蒙脱土纳米复合材料的制备与表征

为解决苯并噁嗪树脂(BZ)固化温度高和固化后韧性差的问题,首先制备了苯并噁嗪叔铵盐(Bz盐),并通过阳离子交换反应对蒙脱土(Na-MMT)进行改性,得到Bz盐改性蒙脱土(Bz-MMT);其次,将Bz-MMT与BZ共混,通过除泡和加热固化,制备了苯并噁嗪树脂/蒙脱土纳米复合材料(PBZ/Bz-MMT);最后,采用X射线衍射(XRD)、差示扫描量热法(DSC)和热重分析(TGA)等对Bz-MMT、BZ和MMT的混合物以及固化后的PBZ/Bz-MMT纳米复合材料进行分析,分别考察了Bz盐的用量对Bz-MMT层间距和热稳定性的影响、Bz-MMT对BZ的固化温度以及对PBZ/Bz-MMT热稳定性和力学性能的影响.结果表明:随着Bz盐用量的增加,Bz-MMT的层间距基本不变、有机含量提高、起始热分解温度降低;采用Bz-MMT改性BZ,不仅可以降低BZ的起始固化温度,而且能有效地提高PBZ/Bz-MMT的"残炭率"、拉伸强度和冲击强度.     

聚丙烯酸钠高吸水性树脂的插层改性与吸水性能

对钠基蒙脱土进行有机化改性处理,并把改性后的蒙脱土分散于丙烯酸钠水相中,用反相悬浮聚合法合成出蒙脱土插层聚丙烯酸钠高吸水性树脂.用IR、XRD等进行结构分析、表征,结果表明:合成树脂的网络内含有蒙脱土,且充分撑开,纳米量级均匀分散在聚合物基体中;加入10%改性蒙脱土,能显著提高树脂的凝胶强度、保水能力和吸水速度等性能. 更多还原     

改性蒙脱石及其不饱和聚酯树脂纳米复合材料

以天然钙基膨润土为原料,制备稳定的钠基蒙脱石悬浮液.再以邻苯二甲酸为改性剂,Co2＋作为沉淀剂,制备有机蒙脱石,并探索了原料配比对蒙脱石改性效果的影响.XRD表明：经邻苯二甲酸改性的蒙脱石d001层间距被撑开到1.31823 nm,说明部分有机物进入到蒙脱石层间,制备出了半剥离状态的有机蒙脱石.将制得的有机蒙脱石与不饱和聚酯树脂原位复合,并对复合材料的冲击强度进行测试.结果表明：与纯不饱和聚酯树脂相比,当有机土的添加量为3%时,复合材料的冲击强度是不饱和聚酯树脂的1.43倍.     

Synthesis and Characterization of Al-Cr-Pillared Montmorillonite with High Thermal Stability and Adsorption Capacity

Al-Cr-pillared montmorillonite was synthesized by using bentonite and Al-Cr pillaring solutions as starting materials. The basal spacing and specific surface areas of the materials were significantly increased relative to those of untreated clays. When the Al/Cr molar ratio(R) was 0.10, the d(001 ) value and specific surface area of pillared montmorillonite were 1.9194 nm and 165.7 m^2 g^-1 , respectively. Thermal stability of the materials was determined using calcined tests and X-ray diffraction ( XRD ) analysis. The materials formed at different R(0.05;0.10;0.15;0.25) exhibit a high thermal stability at 300℃ , especially at initial R = 0.10, the basal interlayer spacing of materials is stabilized at 1.7313 nm after calcined at 500℃ for 2 h. Adsorption behavior of the materials was studied by adsorption experiments. The results show that the Al-Cr-pillared montmorillonites exhibit much stronger adsorption capacity on Cr^6 in aqueous solution than untreated clays do.     

阳离子和阴-阳离子改性剂与蒙脱土作用机制的对比分析

以天然蒙脱土为原料,分别利用阳离子和阴-阳离子改性剂对其进行改性,对改性后的有机蒙脱土进行了表征:IR结果证明有机改性剂已进入了蒙脱土层间,XRD结果表明有机蒙脱土的层间距得到了不同程度的扩增.研究表明,阴-阳离子混和改性剂优于单一的阳离子改性剂,改性剂量不超过1.0 CEC时,蒙脱土层间距由1.538 nm分别扩增到2.643 nm和2.373nm;并对其作用机制进行了详细探讨,为蒙脱土的有机改性提供了新的思路和参考.     

聚丙烯/PP-g-MA/蒙脱土纳米复合材料的制备和性能研究

采用聚丙烯接枝马来酸酐（PP-g-MA）作增容剂改性聚丙烯（PP）/蒙脱土（MMT）纳米复合材料,研究了不同PP-g-MA含量对PP/PP-g-MA/MMT的流动性、拉伸强度、冲击强度、耐热性、晶体形貌以及MMT分散的影响。结果表明：当PP-g-MA的质量分数为5%时,PP基体的晶粒细化,MMT分散得以改善,拉伸强度基本不变,冲击强度却大幅度增加。     

无皂乳液聚合制备PMMA／MMT纳米复合材料的研究

采用离子交换法,用溴化烯丙基三乙基铵对钠基蒙脱土进行改性制备了有机蒙脱土,再以甲基丙烯酸甲酯（MMA）为单体,过硫酸钾为引发剂,通过无皂乳液聚合制备聚甲基丙烯酸甲酯朦脱土（PMM-MMT）纳米复合材料。采用傅里叶变换红外（FTIR）、X-射线衍射（XRD）和扫描电镜（SEM）等手段对有机蒙脱土和复合材料的结构进行表征。结果表明：溴化烯丙基三乙基铵成功插层到蒙脱土层间,层间距由1．32nm增大到1．44nm;FTIR和XRD测试结果表明不同蒙脱土含量的PMMA/MMT纳米复合材料均具有剥离型结构;SEM测试结果表明PMMA/MMT纳米复合粒子的粒径随蒙脱土含量的增加而减小。     

γ-聚谷氨酸对蒙脱土的插层研究

以γ-聚谷氨酸（γ-PGA）和蒙脱土（MMT）为原料,采用溶液插层法制备γ-PGA/MMT复合材料.研究了γ-PGA分子量、插层时间和插层温度对插层效果的影响,并探讨了γ-PGA在MMT中的形态.实验结果显示,不同分子量的γ-PGA,均能对MMT实现插层;MMT的层间距随着插层时间的延长逐渐增大,在8 h后达到最大,随后略有下降;MMT的层间距随着插层温度的升高逐渐增大,在60℃时达到最大值,温度继续升高则有所下降;γ-PGA分子在MMT的片层间为α-螺旋构象,且呈单分子层排列.     

二乙醇胺改性钠基蒙脱石的制备

研究采用微波法制备二乙醇胺有机蒙脱石的适宜条件,并将改性后的有机蒙脱石加入到对苯二甲酸二甲酯和乙二醇中发生醇解共聚反应,利用IR、XRD等对有机蒙脱石及醇解共聚物进行表征.结果表明：二乙醇胺改性钠基蒙脱石的适宜二乙醇胺加入量为土浆所含干土质量的18%;适宜的反应时间为20 min,反应温度为60℃;经二乙醇胺改性的有机蒙脱石的层间距由钠基蒙脱石层间距的1.27 nm增加到1.37 nm.     

Effect of organophilic montmorillonite on thermal-oxidative aging behavior of SBS modified bitumen crack filling material

Styrene-butadiene-styrene (SBS) modified bitumen crack filling material with organophilic montmorillonite (OCFM) was prepared by melt blending. X-ray diffraction analysis shows that the interlayer spacing of organophilic montmorillonite (OMMT) in OCFM is widened and an exfoliated structure may be formed. Thermal-oxidative aging behavior of OCFM and SBS modified bitumen crack filling material (SCFM) was investigated. The experimental results indicate that the rate of thermal-oxidative aging of OCFM is much slower than that of SCFM, which can be attributed to barrier of exfoliated structure of OCFM to oxygen. Funded by the National Natural Science Foundation of China (50773061)     

反应挤出制备HDPE／PA6／MMT复合材料研究

通过反应挤出制备了高密度聚乙烯／聚酰胺6／蒙脱土（HDPE／PA6／MMT）复合材料,研究了MMT在HDPE／PA6共混物中的分散和分布情况,及其对共混物相态结构的影响。从XRD和TEM的结果中可以看出,有机化蒙脱土（OMMT）选择性地分布在PA6相内以及两相的界面上,钠基蒙脱土（Na＋MMT）则主要分布在PA6相内;大部分OMMT得到较好的剥离或插层,而Na＋MMT出现明显的团聚。FE—SEM分析结果表明,增大MMT的含量会导致PA6的相态尺寸变大,粒径分布变宽。流变分析结果表明,由于OMMT部分分布于两相界面处,从而增强了界面结合,对共混物起到了增容作用。     

环氧树脂/蒙脱土纳米复合材料的制备及性能研究

采用双子季铵盐对蒙脱土进行有机化处理，再与环氧树脂进行插层复合制备了环氧树脂／蒙脱土复合材料、借助XRD和FTIR等手段对改性蒙脱土进行了表征，对复合材料的力学性能进行测试。结果表明，改性使蒙脱土层间距增大，有机蒙脱土的加入改善了环氧树脂基体的力学性能，当有机蒙脱土质量含量为1％时，其弯曲强度、冲击强度等力学性能得到了最大的提高。     

PE/PEMA/MMT纳米复合材料的制备与性能

采用熔融插层法制备了聚乙烯／马来酸酐接枝聚乙烯／蒙脱土(PE／PEMA／MMT)纳米复合材料,研究了不同质量分数的蒙脱土对聚乙烯力学性能、热稳定性能及对有机溶剂的阻隔性的影响,并用X射线衍射法对材料的微观结构进行了表征．结果表明,聚乙烯分子链已插层进入蒙脱土层间,材料的拉伸强度最大提高了13．5％,热分解温度有一定程度的提高,材料对有机溶剂的阻隔性也有所改善、     

Preparation and properties of gelatin-chitosan/montmorillonite drug-loaded microspheres

A kind of slow release drug-loaded microspheres were prepared with gelatin, chitosan and montmorillonite(MMT) by an emulsification/chemical cross-linking method using glutaraldehyde as cross-linking agent and acyclovir as model drug. The microspheres were characterized by X-ray diffraction (XRD), Fourier transform infrared (FT-IR) and scanning electron microscopy (SEM), respectively. The morphology, drug content, encapsulation efficiency and drug-release behavior were investigated with different MMT content...     

The coupling agents’ effects on the BSA intercalated into montmorillonite

The effects of surface modification on montmorillonite （MMT） were illustrated in order to produce the composite material with premium properties. MMT was treated with two coupling agents： glutaraldehyde （GA） and 7-methacryloxy-propyl-trimethoxy silane （KH570）. The effects of different coupling agents on MMT and protein interaction were investigated by XRD, FT-IR, TGA, UV-Vis, etc. The results of structure characterization indicated that KH570 modification could change the surface crystal structure of MMT. However, GA reacted with amino groups of Bovine serum albumin （BSA） and the ordered layer structures of MMT were not completely destroyed. Coupling agents could greatly increase the amounts of BSA intercalated and the effect of KH570 is better than that of GA. And, the optimum concentrations of KH570 and GA were 2% and 6%, respectively. The rate of weight loss increased by about 12% after MMT was pretreated with coupling agents. The possible reason is that coupling agent treatment makes the structure of MMT more accessible to protein absorption and helps to stabilize the protein structure. Moreover,the presence of coupling agents can reduce the direct chemical interaction between BSA and MMT, which results in increasing protein desorption.