酪素-蒙脱土杂化物热降解行为研究

酪素加热溶解后与[CH3(CH2)15N(CH3)3] -蒙脱土插层物混合,得到酪素/蒙脱土纳米复合物。热重分析结果表明,复合物的热失重速率最大峰温度略高于纯酪素。分别采用Kissinger,Flynn-Wall-Ozawa和NETZSCH Thermokinetics2软件法求解酪素及其纳米复合材料的热降解活化能。三种方法得到的热分解活化能数值基本吻合,以三种方法的活化能平均值相比较,复合物的降解活化能(14.50 kJ/mol)与纯酪素(16.33 kJ/mol)相比并未升高而是略有降低,表明酪朊蛋白的热降解过程可能受到蒙脱土的催化作用。     

原位接枝插层法制备聚丙烯/蒙脱土纳米复合材料

采用原位接枝插层法制备了聚丙烯/蒙脱土纳米复合材料.借助长链有机胺有机化的蒙脱土在溶液中与马来酸酐和少量辅助溶胀剂进行溶胀;溶胀后的有机蒙脱土再与聚丙烯、适量引发剂在Haake混炼机中进行熔融反应,得到一种聚丙烯/蒙脱土接枝插层共混物;再将接枝插层共混物按一定比例与聚丙烯在Haake混炼机中进行混炼得到聚丙烯/蒙脱土纳米复合材料.用X射线衍射仪(XRD)、透射电镜(TEM)和热失重分析仪(TGA)分别对各步骤的产物进行表征.产物的XRD和TEM分析结果表明蒙脱土完全剥离并均匀分散在聚丙烯基体中,形成了真正的聚丙烯/蒙脱土纳米复合材料.TGA分析结果显示出该纳米复合材料具有相当好的热稳定性.     

NBR/Zn(MAA)2/蒙脱土纳米复合材料的研究

研究NBR／基丙烯酸锌[Zn(MAA)2]／蒙脱土纳米复合材料的性能。结果表明，Zn(MAA)2可以通过原位聚合反应在与NBR发生接枝交联的同时，实现对蒙脱土的插层，用该方法制备的NBR／Zn(MAA)2／蒙脱土纳米复合材料的物理性能优异，含有有机改性蒙脱土HMMT和USM的复合材料性能更为突出，且具有一定的透明性。     

聚丙烯／蒙脱土插层型的纳米复合材料的制备方法

[公开号]1446852[公开日]2003-10-08此发明是一种聚丙烯/蒙脱土纳米复合材料的制备方法。现有技术获得的复合材料性能不令人满意,且工艺复杂。此发明聚丙烯/蒙脱土插层型纳米复合材料的原材料包括:等规聚丙烯、层间距不同的有机改性蒙脱土(TJ1、TJ2、TJ3、TJ4)、接枝改性聚丙烯、接枝改性聚丙烯共聚物。以接枝改性聚丙烯或接枝改性聚丙烯共聚物为改性剂,用母料法熔融插     

纳米插层聚氨酯改性环氧树脂性能研究

采用聚氧化丙烯二醇(N210和N220)、2，4-甲苯二异氰酸酯(TDI)、有机纳米蒙脱土(OMMT)等为原材料，分别制备了相应的聚氨酯预聚体和有机蒙脱土纳米插层聚氨酯预聚体，并以此对环氧树脂E44进行化学共聚改性，系统地研究了改性环氧树脂复合材料的力学性能等。研究表明，有机蒙脱土纳米插层聚氨酯能大幅度提高环氧树脂复合材料的韧性等，比相应的聚氨酯预聚体改性环氧树脂具有更好的效果。     

聚苯乙烯/蒙脱土纳米复合材料的制备与表征

用十二烷基硫酸钠对钠基蒙脱土进行有机改性，将其层间距打开。用FT—IR和XRD进行表征。结果表明：有机插层剂已插层进入蒙脱土层间，然后利用乳液聚合法制备了聚苯乙烯／蒙脱土纳米复合材料。DTA和TGA分析表明：与纯聚苯乙烯相比，所得聚苯乙烯／蒙脱土(PS／MMT)纳米复合材料的热性能得到提高。     

PBAT/OMMT复合材料的力学性能研究

以可降解聚酯聚对苯二甲酸丁二醇酯-己二酸丁二醇酯(PBAT)、有机蒙脱土(OMMT)为原料,采用熔融插层复合技术制备可降解聚酯(PBAT)/有机蒙脱土纳米复合材料,并对材料的相关性能进行了表征和研究。首先,采用固相插层法以十六烷基三甲基溴化铵(CTAB)为插层剂,对蒙脱土进行有机化处理,并对固相插层工艺进行了详细的研究。结果表明:插层剂用量、搅拌温度,搅拌时间都成为了影响插层效果的因素。然后将有机蒙脱土(OMMT)与PBAT进行熔融插层共混,制得可降解聚酯PBAT/蒙脱土纳米复合材料,并使用X射线衍射(XRD)、拉伸机、差示量热扫描(DSC)对其性能进行表征。考察了蒙脱土含量对复合材料性能的影响。结果表明,熔融插层制备的纳米复合材料的力学性能、热性能等与纯的PBAT相比都有了较大的提高。     

胶乳接枝插层法制备聚丙烯酸酯/蒙脱土复合乳液

本通过胶乳接枝插层法，采用3种不同的蒙脱土制备了聚丙烯酸酯／蒙脱土复合乳液。利用X射线衍射(XRD)和透射电子显微镜(TEM)对复合物的结构进行了分析，并对复合物的热性能、力学性能、耐水性能、表面接触角及耐紫外光性能进行了研究。结果表明：蒙脱土在复合物中呈现纳米级分散，形成了插层型与剥离型共存的微观结构，但其对单体的聚合有一定阻聚作用；3种复合物的力学性能和吸水率都随蒙脱土用量的增加先升高而后下降，表面接触角随蒙脱土用量的增加而提高；耐紫外光能力有显提高。     

三聚氰胺-甲醛树脂／蒙脱土纳米复合材料的研制

采用微波加热离子交换树脂交换法将天然钙蒙脱土转变为镍基蒙脱土。三聚氰胺单体与镍基蒙脱土层间镍离子的络合后,加入甲醛经插层原位聚合制备三聚氰胺-甲醛树脂/蒙脱土纳米复合材料。X射线粉末衍射结果显示,三聚氰胺-甲醛树脂/蒙脱土复合物试样的d_(001)值由1．41nm增至1．84nm,说明蒙脱土的硅酸盐片层被撑开。粘接剪切强度测试结果表明,蒙脱土的加入提高材料的粘接性能。     

PA6/蒙脱土熔融插层复合材料结构与性能分析

通过熔融共混法插层复合制备了聚酰胺(PN)6／蒙脱土纳米复合材料，测试了力学性能并对不同蒙脱土含量的PA 6／蒙脱土纳米复合材料进行了对比。实验表明，通过熔融插层可使PN 6基体插层于蒙脱土中，所得到的复合材料的性能较PN 6有很大提高。蒙脱土特殊的层状结构使得利用熔融共混在机械力的作用下插层到纳米级复合材料成为可能。     

Synthesis of imidazolium salts and their application in epoxy montmorillonite nanocomposites

Considerable research has been conducted in improving the performance characteristics of nanocomposites, however, relatively few attempts have been made to address the thermal stability of nanocomposites. An attempt is being made to improve the thermal properties of nanocomposites by synthesizing imidazolium salts from 2-methyl imidazole and ion exchanging the salts with clay minerals. This study focuses on the role of the chemistry of imidazolium salt(s) used in functionalizing clay and processing conditions in the formulation of epoxy nanocomposites. The nanodispersion of clay in an epoxy matrix is evaluated qualitatively by X-ray diffraction (XRD), transmission electronic microscopy (TEM), and laser scanning confocal microscopy (LSCM). We demonstrate the use of LCSM for quantitative image analysis and to study the dispersion of clay layers, tagged with a fluorescent dye in the epoxy matrix. XRD and TEM results reveal that the hand mixed nanocomposite has tactoid morphology, while ultrasonicated organoclay (without hydroxyl group) epoxy nanocomposite exhibits a mixed morphology, and an ultrasonicated organoclay (with hydroxyl group) epoxy nanocomposite had well dispersed clay distribution in the epoxy matrix. Results from the three complimentary techniques enable the characterization of the clay platelets over several length scales ranging from the micrometer to the nanometer scale.     

Self-healing and anticorrosive properties of Ce(III)/Ce(IV) in nanoclay–epoxy coatings

The self-healing and anticorrosion effects of cerium nitrate in epoxy–clay nanocomposite coatings systems were studied. Different amounts of cerium (III) were added to epoxy–montmorillonite clay composites and the nanocomposite coatings were prepared and applied on cold rolled steel panels. Ultrasonication was applied to disperse the nanoclay into the epoxy cerium nitrate composition. Electrochemical impedance spectroscopy (EIS) was used to study the self-healing and anticorrosion behaviors of the coatings. The structure of the dry coating and the protective mechanism of the pigments in the coating were investigated by scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDX) analysis and field emission electron microscopy (FESEM). Transmission electron microscopy (TEM) illustrated the separation of clay layers which interacted with the epoxy resin. Electrochemical impedance data indicated that the epoxy cerium (III)–montmorillonite nanocomposite coatings were superior to the epoxy coatings in corrosion protection properties. The self-healing behavior of such coatings was due to the presence of cerium nitrate that could be released at the defects within the coating and hindered the corrosion reactions at the defective sites. It was shown that the best corrosion protection was achieved with nanocomposite coatings containing 4 wt% clay and 2 wt% cerium nitrate.     

丁腈橡胶/粘土纳米复合材料的阻燃性研究

通过利用自制有机改性粘土，采用插层复合法成功制备了丁腈橡胶（NBR）／粘土纳米复合材料。透射电子显微镜（TEM）结果证实了粘土片层在橡胶基体中的纳米级分散。研究结果表明：纳米复合材料的阻燃性能明显高于炭黑补强胶料的阻燃性能。     

Study on the dynamic self‐organization of montmorillonite in two phases

Polycarbonate (PC)/acrylonitrile–butadiene–styrene (ABS) polymer alloy/montmorillonite (MMT) and nylon 6 (PA6)/ABS polymer alloy/MMT nanocomposites were prepared using the direct melt intercalation technique. Their structures were characterized by XRD and TEM. The results of TEM show that the silicate layers dispersed differently in two phases. In the PC/ABS/MMT nanocomposite, the silicate layers were self‐organized in the ABS phase, whereas in the PA6/ABS/MMT nanocomposite, the silicate layers were dispersed in both phases but mainly in the PA6 phase. Furthermore, the PC/MMT nanocomposite was melt‐mixed with pure ABS, and the changed morphology of the hybrid with the change of melt‐mixing time was characterized by XRD and TEM, to study the dynamic self‐assembly of clay layers in two phases. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 91: 1457–1462, 2004     

以阳离子Gemini表面活性剂为模板合成介孔氧化硅

以阳离子Gemini表面活性剂——双十六烷基三甲基溴化铵[C16H33N+(CH3)2(CH2)2N+(CH3)2C16H33].2Br-(G16-2-16)为模板剂,正硅酸乙酯为硅源,在n(SiO2)∶n(G16-2-16)∶n(NH3)∶n(H2O)=1∶0.1∶9∶110的条件下,在弱碱性环境中用水热法合成了平均孔径3.1 nm、比表面积906.71 m2/g、孔容0.93 cm3/g、具有二维六角结构且高度有序的介孔氧化硅MCM-41。采用小角XRD、高分辨透射电镜(HRTEM)、N2吸附-脱附分析和热重-微分热重法(TG-DTG)对其结构进行了考察,分析了不同模板剂浓度对材料结构有序度的影响。结果表明,n(G16-2-16)/n(TEOS)=0.1时,合成的材料有序度最高。     

Preparation of polyethylene‐octene elastomer/clay nanocomposite and microcellular foam processed in supercritical carbon dioxide

Polyethylene‐octene elastomer (POE)/organoclay nanocomposite was prepared by melt mixing of the POE with an organoclay (Cloisite 20A) in an internal mixer, using poly[ethylene‐co‐(methyl acrylate)‐co‐(glycidyl methacrylate)] copolymer (E‐MG‐GMA) as a compatibilizer. X‐ray diffraction and transmission electron microscopy analysis revealed that an intercalated nanocomposite was formed and the silicate layers of the clay were uniformly dispersed at a nanometre scale in the POE matrix. The nanocomposite exhibited greatly enhanced tensile and dynamic mechanical properties compared with the POE/clay composite without the compatibilizer. The POE/E‐MA‐GMA/clay nanocomposite was used to produce foams by a batch process in an autoclave, with supercritical carbon dioxide as a foaming agent. The nanocomposite produced a microcellular foam with average cell size as small as 3.4 µm and cell density as high as 2 × 10¹¹ cells cm^?3. Copyright © 2005 Society of Chemical Industry     

Preparation and barrier property of poly(ethylene terephthalate)/clay nanocomposite using clay‐supported catalyst

Poly(ethylene terephthalate) (PET)/clay nanocomposite was prepared by the direct polymerization with clay‐supported catalyst. The reaction degree of catalyst against the cation exchange capacity of clay was 8 wt %. The intercalation of PET chains into the silicate layers was revealed by X‐ray diffraction studies. SEM morphology of the nanocomposite showed a good dispersion of clay‐supported catalyst, ranging from 30 to 100 nm. The intercalated and exfoliated clay‐supported catalyst in PET matrix was also observed by TEM. The improvement of O₂ permeability for PET/clay‐supported catalyst composite films over the pure PET is approximately factors of 11.3–15.6. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 4875–4879, 2006     

一步法柴油相转移催化氧化脱硫研究

制备了两种磷钼酸季铵盐类相转移催化剂[C16H33(CH3)3N]2[HPMo12O40]和[(CH3CH2)4N]2[HPMo12-O40],以30%的H2O2为氧化剂,易回收、无毒复合溶剂为萃取剂,采用一步氧化萃取脱硫法和两步氧化萃取脱硫法对直馏柴油进行了氧化脱硫研究。结果表明,一步法脱硫效果比两步法好,[C16H33(CH3)3N]2[HPMo12O40]的脱硫效果优于[(CH3CH2)4N]2[HPMo12O40],适宜的反应条件为:O/S比(摩尔比)为8∶1,催化剂用量5%,反应温度40℃,反应时间80 min,萃取剂油比1(体积比),此时直馏柴油的脱硫率为61.3%,收率为95%,催化剂重复使用5次后,脱硫率没有明显下降。     

Enhanced thermal properties of PS nanocomposites formed from inorganic POSS-treated montmorillonite

We have prepared polystyrene/clay nanocomposites using an emulsion polymerization technique. The nanocomposites were exfoliated at up to a 3 wt% content of pristine clay relative to the amount of polystyrene (PS). We used two different surfactants for the montmorillonite: the aminopropylisobutyl polyhedral oligomeric silsesquioxane (POSS) and the ammonium salt of cetylpyridinium chloride (CPC). Both surfactants can intercalate into the layers of the pristine clay dispersed in water prior to polymerization. Although the d spacing of the POSS-intercalated clay is relatively smaller than that of the CPC-intercalated clay, PS more easily intercalates and exfoliates the POSS-treated clay than the CPC-treated clay. IR spectroscopic analysis further confirms the intercalation of POSS within the clay layers. We used X-ray diffraction (XRD) and transmission electron microscopy (TEM) to characterize the structures of the nanocomposites. The nanocomposite prepared from the clay treated with the POSS containing surfactant is exfoliated, while an intercalated clay was obtained from the CPC-treated surfactant. The molecular weights of polystyrene (PS) obtained from the nanocomposite is slightly lower than the virgin PS formed under similar polymerization conditions. The value of T_g of the PS component in the nanocomposite is 8 °C higher than the virgin PS and its thermal decomposition temperature (21 °C) is also higher significantly. The presence of the POSS unit in the MMT enhances the thermal stability of the polystyrene.