环氧树脂/蒙脱土纳米复合材料的性能研究进展

阐述了近年来环氧树脂/蒙脱土纳米复合材料的力学性能、阻燃性能、气阻性能、耐热性能的研究进展。指出大幅度提高材料在玻璃态的储存模量与韧性是现阶段有待解决的难题,而探讨插层型复合材料的力学性质及利用蒙脱土开发绿色环保的阻燃材料和气阻材料是当今的研究方向。     

The Influence of Crysnanoclay Addition on Mechanical and Thermal Properties of Thermoplastic Polyurethane Elastomeric with Polycarbonate Nanocomposites

A series of crysnanoclay-loaded thermoplastic polyurethane (TPU) elastomer/polycarbonate (PC) nanocomposites have been prepared using twin screw extruders. The physicomechanical properties such as tensile behaviors, flexural properties and impact strength of the composites have been reported. Significant improvement in tensile modulus and flexural modulus were noticed for nanocomposites. The thermal characteristics of nanocomposites have been determined by thermogravimetric analysis (TGA) techniques. Thermal degradation kinetic parameters such as energy of activation (E_a) have been calculated from TGA thermograms for the nanocomposites using three mathematical models namely; Coats–Redfern, Horowitz – Metzger and Broido's methods and the results are compared. The effect of crysnanoclay on the storage modulus (E′), loss modulus (E″), and damping factor (tan δ) as a function of temperature have been measured by dynamic mechanical analysis (DMA). The storage moduli of nanocomposites have been increased after incorporating crysnanoclay in polymer matrix.     

聚丙烯/蒙脱土纳米复合材料的制备与性能

合成了TiCl4/MgCl2/MMT插层催化剂,通过原位聚合制备了聚丙烯/蒙脱土纳米复合材料。X射线衍射结果表明:蒙脱土在聚丙烯基质中达到了纳米级分散。与纯聚丙烯(PP5004)相比,聚丙烯/蒙脱土纳米复合材料的力学性能、维卡软化点、热变形温度以及热分解温度都有所提高。     

熔融共混制备聚乳酸/蒙脱土纳米复合材料及其性能研究

通过熔融共混制备了聚乳酸/蒙脱土纳米复合材料,研究了蒙脱土对聚乳酸结晶性能、热稳定性、力学性能以及动态力学性能的影响。研究结果表明:蒙脱土对聚乳酸的熔体结晶过程起促进作用;聚乳酸/蒙脱土纳米复合材料的起始热分解温度随蒙脱土含量的增加而升高;适量的蒙脱土可对聚乳酸起增强作用,蒙脱土含量小于5%时,还可改善聚乳酸的韧性。动态力学性能分析结果表明:蒙脱土对聚乳酸的玻璃化转变温度无明显影响但,损耗因子随蒙脱土含量的增加而减小。     

黑山膨润土钠化工艺研究

以黑山天然膨润土为原料,采用阳离子交换树脂交换的方法对天然膨润土进行钠化改型,通过正交试验确定了最佳条件。该方法具有不引入阴离子或沉淀物、分离容易等优点,大大减少了后处理步骤。制备出稳定的钠基蒙脱石悬浮液,干燥后产品的阳离子交换容量是127.88 mmol/100 g,吸蓝量为42.35 g/100 g,蒙脱石纯度达到了95.81%。XRD衍射分析表明产品达到高品质钠基蒙脱石的要求,为其深层次的加工应用打下良好的基础。     

Sulfonated Styrene-(ethylene-co-butylene)-styrene/Montmorillonite Clay Nanocomposites: Synthesis, Morphology, and Properties

Sulfonated styrene-(ethylene-butylene)-styrene triblock copolymer (SSEBS) was synthesized by reaction of acetyl sulfate with SEBS. SSESB-clay nanocomposites were then prepared from hydrophilic Na-montmorillonite (MT) and organically (quaternary amine) modified hydrophobic nanoclay (OMT) at very low loading. SEBS did not show improvement in properties with MT-based nanocomposites. On sulfonation (3 and 6 weight%) of SEBS, hydrophilic MT clay-based nanocomposites exhibited better mechanical, dynamic mechanical, and thermal properties, and also controlled water–methanol mixture uptake and permeation and AC resistance. Microstructure determined by X-ray diffraction, atomic force microscopy, and transmission electron microscopy due to better dispersion of MT nanoclay particles and interaction of MT with SSEBS matrix was responsible for this effect. The resulting nanocomposites have potential as proton transfer membranes for Fuel Cell applications.     

聚合物/蒙脱土纳米复合材料的研究进展

简要概述了聚合物/蒙脱土纳米复合材料的结构及性能,详细介绍了聚酰胺/蒙脱土、聚烯烃/蒙脱土和热固性树脂/蒙脱土纳米复合材料的研究进展。并总结了复合材料的各种优异性能,分析了蒙脱土提高复合材料性能的机理。     

聚合物基蒙脱土纳米复合材料热稳定性能及阻燃性能

综述了近年来国内外聚合物基蒙脱土纳米复合材料热性能和阻燃性能方面的研究进展及机理,并对蒙脱土与其他绿色阻燃剂协同阻燃的前景进行了展望。     

插层剂对尼龙6/蒙脱土纳米复合材料性能的影响

用3种不同的插层剂有机化蒙脱土,并分别与尼龙6熔融共混制得了尼龙6/蒙脱土纳米复合材料,对热变形温度(HDT)和力学性能进行了研究。结果表明:与纯尼龙6相比,3种复合材料的HDT、拉伸模量、弯曲模量、弯曲强度有明显提高,屈服强度也有所提高,而冲击强度和断裂伸长率则有所下降;其中,含羟基的插层剂对复合材料的综合改性效果最好。     

聚乙烯醇/蒙脱石纳米复合材料的结构与性能

通过溶液插层 流延成膜法,以聚乙烯醇和钠质蒙脱石为原料,制备出了不同蒙脱石含量的聚乙烯醇/蒙脱石纳米复合材料薄膜。用X射线衍射(XRD)、扫描电子显微镜(SEM)、热重分析(TGA)和力学性能测试对复合材料的结构和性能进行了表征。结果表明,聚乙烯醇分子成功进入蒙脱石的层间,实现了在纳米尺度上的复合;蒙脱石含量高于7 5wt%形成插层型的纳米复合材料,低于7 5wt%形成剥离型的纳米复合材料;在SEM图片上还观察到了纳米复合材料的微观结构。纳米复合材料的热稳定性、拉伸强度和直角撕裂强度均比纯聚乙烯醇有很大提高。     

Thermal and Antistatic Properties of Polypropylene/Organo Montmorillonite Nanocomposites

Both polypropylene (PP) and PP/organo-montmorillonite (OMMT) masterbatch containing antistatic agent (3–9 wt%) were prepared by using co-rotating twin screw extruder followed by injection molding. PP/OMMT masterbatch was prepared by mixing PP, OMMT and maleated PP (PPgMAH). The PP nanocomposites were characterized by using X-ray diffractometer (XRD), differential scanning calorimeter (DSC), thermogravimetry analyzer (TGA), hardness and surface resistivity tests. XRD results indicated that AA could promote the intercalation in PP/OMMT nanocomposites. The decomposition temperature of PP/OMMT/AA nanocomposites is higher than that of PP/OMMT. The hardness, degree of crystallinity and surface resistivity of PP nanocomposites was influenced by the addition of antistatic agent.     

Morphology,Thermal and Mechanical Properties of Poly (Styrene-Acrylonitrile) (SAN)/Clay Nanocomposites from Organic-Modified Montmorillonite

Poly (styrene-acrylonitrile) (SAN)/clay nanocomposites have successfully been prepared by melt intercalation method. The hexadecyl triphenyl phosphonium bromide (P16) and cetyl pyridium chloride (CPC) are used to modify the montmorillonite (MMT). The structure and thermal stability property of the organic modified MMT are, respectively characterized by Fourier transfer infrared (FT-IR) spectra, X-ray diffraction (XRD) and thermogravimetric analysis (TGA). The results indicate that the cationic surfactants intercalate into the gallery of MMT and the organic-modified MMT by P16 and CPC has higher thermal stability than hexadecyl trimethyl ammonium bromide (C16) modified MMT. The influences of the different organic modified MMT on the structure and properties of the SAN/clay nanocomposites are investigated by XRD, transmission electronic microscopy (TEM), high-resolution electron microscopy (HREM), TGA and dynamic mechanical analysis (DMA), respectively. The results indicate that the SAN cannot intercalate into the interlayers of the pristine MMT and results in microcomposites. However, the dispersion of the organic-modified MMT in the SAN is rather facile and the SAN nanocomposites reveal an intermediate morphology, an intercalated structure with some exfoliation and the presence of small tactoids. The thermal stability and the char residue at 700°C of the SAN/clay nanocomposites have remarkably enhancements compared with pure SAN. DMA measurements show that the silicate clays improve the storage modulus and glass transition temperature (Tg) of the SAN matrix in the nanocomposites.     

PEN／MMT纳米复合材料结晶动力学的研究

采用熔融插层法制备聚2,6-萘二甲酸乙二酯(PEN)/蒙脱土(MMT) 纳米复合材料,用Avrami方程和张志英方法对所得数据进行了等温结晶和非等温结晶动力学的研究.结果表明,在PEN/MMT共混物中由于MMT的加入,降低了PEN/MMT的结晶活化能,导致共混物的结晶速率提高;MMT含量影响共混物的结晶速度,加入少量的MMT可以明显提高共混物的结晶速率;共混物的表面活化能的变化与Avrami方程得出的n值变化相似,MMT的含量影响共混物成核结晶速度.     

聚乙烯/蒙脱土纳米复合材料结构与力学性能的研究

制备了MMT/MgCl2/TiCl4插层型催化剂,并进行乙烯聚合。考察了MMT片层间距、复合材料形态及蒙脱土在其中的分布状态。考察了材料的冲击强度、拉伸强度等力学性能及蒙脱土的最佳含量。     

蒙脱土结构特性及在聚合物基纳米复合材料中的应用

对蒙脱土的晶层结构、分散性、流变性及表面修饰进行了系统的评述。蒙脱土片层含有Lewis酸点及过渡金属离子可用于烯类单体的催化聚合反应;自从丰田汽车公司使用尼龙 6／粘土纳米复合材料以来,蒙脱土(具有膨润性的粘土)在聚合物基纳米复合材料中的研究和应用正越来越受到世人的关注。对蒙脱土／聚合物纳米复合材料的制备方法及其进展也进行了综述。     

Effects of Charring Agents on the Thermal and Flammability Properties of Intumescent Flame-Retardant HDPE-based Clay Nanocomposites

Intumescent flame-retardant (IFR) high-density polyethylene, poly[ethylene-co-(vinyl acetate)], and organically-modified clay nanocomposites consisting of ammonium polyphosphate (APP) and other charring agents, as well as the nanocomposites pentaerythritol (PER), polyamide-6 (PA), and PA/OMT were investigated. Their thermal and flammability properties have been characterized by thermogravimetric analyses, cone calorimetry, a limiting oxygen index, and the UL-94 test. Results show that the PER-contained sample exhibits different thermal and flammability behaviors from the samples containing polymer charring agents. The difference is postulated to be responsible for the formation of various intumescent structures and their changes in response to heightened temperatures.     

聚烯烃/蒙脱土纳米复合材料研究进展

简要概述了蒙脱土的有机改性机理、聚烯烃/蒙脱土纳米复合材料的制备方法、结构与表征以及聚烯烃/蒙脱土纳米复合材料的研究进展。     

Effect of Clay Types on the Mechanical,Dynamic Mechanical and Morphological Properties of Polypropylene Nanocomposites

In the present investigation Polypropylene–Maleic anhydride grafted polypropylene–organically modified MMT (PP-MAPP-OMMT) nanocomposites were prepared by melt mixing in a twin screw extruder followed by injection molding. The effect of clay chemistry and compatibilizer on the properties of the nanocomposites has been studied. Sodium montmorillonite has been organically modified using quaternary and alkyl amine intercalants. A comparative account with commercial quaternary ammonium modified clays i.e Cloisite 20A, Cloisite 15A and Cloisite 30B has been presented. Storage modulus of PP matrix also increased in the nanocomposites, indicating an increase in the stiffness of the matrix polymer with the addition of organically modified nanoclays. The morphology of the nanocomposites has been examined using wide angle X-ray diffraction (WAXD) and transmission electron microscopy (TEM). Morphological findings revealed efficient dispersion of organically modified nanoclays within the PP matrix. MAPP compatibilized PP/Cloisite 15A nanocomposites displayed finely dispersed exfoliated nanomorphology as compared with other systems.     

PMMA/蒙脱土纳米复合材料的结构及热性能

以甲基丙烯酸二甲胺基乙酯和1-溴正十六烷为原料合成了1种新型的带双键长碳链季铵盐甲基丙烯酰氧乙基十六烷基二甲基溴化铵(MHAB).用MHAB对钠基蒙脱土进行改性得到有机蒙脱土(OMMT).通过本体原位插层聚合制备了的聚甲基丙烯酸甲酯/蒙脱土纳米复合材料.MHAB的结构通过核磁共振氢谱(1H-NMR)表征.X射线衍射(XRD)测得OMMT的001面层间距(d001)从1.25 nm扩大到2.72 nm.XRD和透射电镜(TEM)测试证明蒙脱土质量分数为5%,8%时完全以剥离片层形式存在于复合材料中.差示扫描量热仪(DSC)和热失重仪(TG)测试表明复合材料的玻璃化转变温度和外推起始热失重温度都随着蒙脱土的含量增加而提高.     

不饱和聚酯树脂/蒙脱土纳米复合材料的研制

通过微波交换法将天然钙基蒙脱土转变为钠基蒙脱土，进而转变成镍基蒙脱土。镍基蒙脱土与1，2-丙二醇进行络合，再与顺丁烯二酸酐和邻苯二甲酸酐缩聚为不饱和聚酯，并固化为不饱和聚酯树脂/蒙脱土纳米复合材料，使不饱和聚酯树脂的抗弯性能得以大大改善。