固相法插层改性黏土在PP中的应用

采用固相法对黏土进行有机化插层改性制备有机黏土,再通过熔融插层法制备聚丙烯(PP)/有机黏土纳米复合材料。有机黏土在PP中的层间距由原来的4.07 nm扩大到5.84 nm,PP分子链成功插入到固相法改性的黏土中,形成纳米复合材料。PP/有机黏土纳米复合材料的结晶温度由112.9℃提高119.6℃,熔融过程、熔点及结晶度没有明显变化。PP/有机黏土纳米复合材料的力学性能优于PP/钠基黏土复合材料,有机黏土的质量分数在3%-5%时,纳米复合材料的力学性能最佳。     

聚丙烯/黏土纳米复合材料结构及流变性能研究

采用固相法对黏土进行插层改性,制备有机黏土,再与聚丙烯熔融共混,成功制备聚丙烯/有机黏土纳米复合材料。XRD和TEM测试均表明:固相法改性黏土可以与聚丙烯形成结构为插层型和剥离型共存的纳米复合材料。利用动态流变仪研究纳米复合材料的加工流变性能,结果显示,有机黏土的加入有效地改善了聚丙烯的加工流变性能。     

季鏻盐改性黏土及其对尼龙6性能的影响

首先采用季鏻盐作为插层剂对钠基黏土进行插层改性,制备有机黏土,再与尼龙6熔融共混,成功制备尼龙6/有机黏土纳米复合材料。XRD测试结果表明:季鏻盐改性黏土可以与尼龙6形成纳米复合材料。转矩流变仪的测试结果显示:有机黏土能够略微改善尼龙6树脂的加工性能。力学性能的测试结果显示:有机黏土的含量在3%~5%范围内其,纳米复合材料的力学性能最佳。     

固相法改性粘土及其在聚氯乙烯中的应用

首先采用固相法对粘土进行有机化插层改性,制得有机粘土,再通过熔融插层法制备聚氯乙烯/有机粘土复合材料。XRD表明固相法改性粘土可以与聚氯乙烯形成纳米复合材料。利用DSC研究了纳米复合材料的玻璃化转变温度,结果显示:聚氯乙烯/有机粘土纳米复合材料的玻璃化转变温度高于纯聚氯乙烯。     

PP/黏土纳米复合材料的结构与性能

采用熔体插层法制备聚丙烯（PP）/有机黏土（OMMT）纳米复合材料。XRD和TEM的测试结果表明,采用熔体插层法制备的PP/OMMT复合材料是剥离型纳米复合材料。力学性能实验结果表明,相容剂的加入提高了PP与OMMT之间的相互作用,使其各项力学性能都得到了提高;PP/OMMT纳米复合材料的各项力学性能在有机黏土含量较小的情况下,就可以有较大幅度的提高;与纯PP相比,相容剂含量为10 phr、有机黏土用量为1 phr的聚丙烯基纳米复合材料具有最好的各项力学性能。     

有机改性与乳液插层法相结合制备的丁苯橡胶/黏纳米复合材料的结构与性能(英文)

针对现有的乳液插层法所制备的橡胶/黏土纳米复合材料中填料与橡胶之间界面结合较弱的缺点,在乳液插层法中对无机黏土进行有机改性,制备出力学性能优异的纳米复合材料。X射线衍射和透射电子显微镜技术分析表明,有机改性后的复合材料中黏土被部分地有机改性,且在基体中以纳米尺寸分散。     

聚丙烯/蒙脱土纳米复合材料的制备与表征

利用固相剪切法使蒙脱土片层完全剥离,制备聚丙烯/蒙脱土(PP/MMT)纳米复合材料,通过X射线衍射、扫描电镜、力学性能的实验得出：用水做为膨胀剂可使蒙脱土的层间距胀大,有利于PP分子的插层和蒙脱土的剥离;固相剪切法和熔融过程使蒙脱土完全地层状剥离,均匀纳米级分散在聚丙烯基体中,沿流动方向取向; PP与用水处理过的有机改性蒙脱土复合材料的冲击强度由5.68 kJ/m2提高到了8.2 kJ/m2,大量提升了材料的冲击性。     

有机改性与乳液插层法相结合制备的丁苯橡胶/黏土纳米复合材料的结构与性能

针对现有的乳液插层法所制备的橡胶／黏土纳米复合材料中填料与橡胶之间界面结合较弱的缺点,在乳液插层法中对无机黏土进行有机改性,制备出力学性能优异的纳米复合材料。X射线衍射和透射电子显微镜技术分析表明,有机改性后的复合材料中黏土被部分地有机改性,且在基体中以纳米尺寸分散。     

偶联剂对PVC/粘土的插层效果及性能研究

采用固相法，对粘土进行有机插层改性；并与聚氯乙烯（PVC）熔融插层制备了纳米复合材料。结果表明，偶联剂KH560处理的有机粘土（用Org-560表示）与PVC形成PVC／org-550插层型纳米复合材料，而偶联剂KH550处理的有机粘土（用Org-550表示）与PVC形成的PVC／Org-550则是剥离型纳米复合材料；PVC／有机粘土纳米复合材料的玻璃化转变温度高于PVC；Org-550对PVC的力学性能优于Org-560的。     

PVC/黏土纳米复合材料研究进展

文章简要概述了黏土的有机改性机理,聚氯乙烯/黏土纳米复合材料的特性及其制备方法、结构与表征方面的研究进展。对熔融插层共混法、溶液插层共混法、原位聚合法和插层聚合法进行了介绍和比较,对聚氯乙烯/黏土纳米复合材料的重点研究领域和发展趋势提出了具有前瞻性的预测。     

EVOH/clay nanocomposites produced by melt processing

Ethylene‐vinyl alcohol copolymer(EVOH)/clay nanocomposites were prepared via a dynamic melt‐intercalation process. The phase morphology and the crystallization behavior of the nanocomposites were investigated, using DSC, DMTA, XRD and SEM. It was found that the treated clay content and dynamic processing time affect the viscosity of the EVOH/clay mixtures: higher clay contents and longer mixing times result in higher torque/viscosity levels. This is due to the increased interaction of the molten polar matrix (EVOH) with the treated organosilicate surface. Under the dynamic high shearing forces, the polymer penetrates the clay agglomerates/aggregates, intercalates within the organoclay galleries, and finally causes delaniination. Thermal analysis of the EVOH/clay nanocomposites showed that the melting temperature, crystallization temperature and heat of fusion of the EVOH matrix, sharply decrease with increasing both, the clay content and processing time. The intercalation level was characterized by X‐ray diffraction (XRD), which verified an increased gallery height. The DMTA spectra showed that longer processing times resulted in higher damping (E″ intensity) levels of the EVOH/clay composites, indicating higher fractions of the EVOH amorphous phase. However, no Tg changes were seen in spite of the high polymer/treated clay interaction levels, which may be attributed to a plasticizing effect of the low molecular weight organic cations.     

聚丙烯/蒙脱土纳米复合材料的制备和性能

采用熔融插层法在双螺杆挤出机中制备了聚丙烯(PP)/蒙脱土(MMT)纳米复合材料,纳米复合材料机械性能测试结果表明,当有机MMT质量分数为2%时,复合材料的弯曲强度明显优于PP。扫描电镜观测不到纳米复合材料中明显的有机-无机相畴,表明MMT片层分散均匀,分散尺度已基本达到纳米级。DSC(差示扫描量热仪)分析测试结果表明,MMT的加入提高了PP的结晶速率,并使结晶度增大。     

聚丙烯／蒙脱土纳米复合材料的制备与性能

用烷基季铵盐对钠基蒙脱土进行有机化处理,使其成为有机蒙脱土。X射线衍射（XRD）表明有机阳离子已同钠离子发生离子交换作用,导致层间距扩大。用熔融插层法制备聚丙烯／蒙脱土纳米复合材料,测试了力学性能。通过XRD、DSC等手段研究了其结构与结晶行为,并与聚丙烯进行了对比。实验表明,通过熔融插层可使聚丙烯插层于蒙脱土片层之中,且所得聚合物的冲击强度有所提高。     

熔融插层法制备聚丙烯/粘土复合材料及性能研究——Ⅱ增容剂和粘土对聚丙烯结晶形态的影响

通过添加不同含量的粘土制备了三个不同类型(PP/DK1,PP/PPMA/DK1,PP/PPMA+DK1)纳米粘土/聚丙烯复合材料。通过对实验样品结晶性能的分析,结果表明:与纯聚丙烯结晶图相比,添加适量的粘土作为成核剂,能够使聚丙烯的球晶数量增多,球晶尺寸变小。同时增容剂(PPMA)的加入也会影响PP的结晶,使球晶尺寸不规整。     

Morphology,Rheological Properties,and Crystallization Behavior of Polypropylene/Clay Nanocomposites

Polypropylene/clay nanocomposites (PP/I.44P, PPCNs) were prepared in a twin-screw extruder using maleic anhydride grafted polypropylene (MAPP) as a compatibilizer. The intercalation of polypropylene into nanoclay particles was studied using X-ray diffraction. Rheological properties of the nanocomposites were investigated using a rheometer. The enhanced complex viscosity at low frequency regime indicated that the melt elasticity and melt strength of the nanocomposites were improved by adding nanoclay. The non-isothermal crystallization behavior of the nanocomposites was studied using differential scanning calorimetry (DSC) at various cooling rates and was analyzed with the Avrami method. It was found that the nanoclay acted as a heterogeneous nucleating agent resulted in higher crystallization temperature and higher crystallization rate than neat PP. Polarized optical microscopy revealed that the spherulites in the nanocomposites were finer than in the neat system.     

Thermal,mechanical, and barrier properties of polyethylene/surlyn/organoclay nanocomposites blown films prepared by different mixing methods

(Low‐density polyethylene) (LDPE)/clay nanocomposites were prepared by melt blending in a twin‐screw extruder by using different mixing methods. Zinc‐neutralized carboxylate ionomer was used as a compatibilizer. Blown films of the nanocomposites were then prepared. The effect of mixing method on the clay dispersion and properties of the nanocomposites was evaluated by wide‐angle X‐ray diffraction analysis, mechanical properties, thermal properties, and barrier properties. The structure and properties of nanocomposites containing different amounts of nanoclay prepared by selected mixing techniques were also investigated. It was found that melt compounding of Surlyn/clay masterbatch with pure LDPE and Surlyn (two‐step‐a method) results in better dispersion and intercalation of the nanofillers than melt mixing of LDPE/Surlyn/clay masterbatch with pure LDPE and surlyn (two‐step‐b method) and direct mixing of LDPE with clay. The films containing ionomer have good barrier properties. A wide‐angle X‐ray diffraction pattern indicates that intercalation of polymer chains into the clay galleries decreases by increasing the clay content. Barrier properties and tensile modulus of the films were improved by increasing the clay content. In addition, tensile strength increased in the machine direction, but it decreased in the transverse direction by increasing the clay content. DSC results showed that increasing the clay content does not show significant change in the melting and crystallization temperatures. The results of thermogravimetric analysis showed that the thermal stability of the nanocomposites decreased by increasing the clay content more than 1 wt%. J. VINYL ADDIT. TECHNOL., 21:60–69, 2015. © 2014 Society of Plastics Engineers     

Polypropylene/montmorillonite composites and their application in hybrid fiber preparation by melt‐spinning

Polypropylene (PP)/organomontmorillonite (OMMT) nanocomposites have been successfully prepared by melt intercalation by using the conventional method of twin‐screw extrusion and subsequently submitted for melt‐spinning. The structure and properties of the PP/clay nanocomposites and hybrid fibers were characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), X‐ray diffraction (XRD), differential scanning calorimetry (DSC), and crystallization dynamics, etc. The organoclay layers were found to disperse in the PP resin at the nanometer level. The nanoscaled OMMT layers, dispersed in the PP matrix, actually played the role of heterogeneous nuclei species in the process of PP crystallization and increased the nucleation speed of the composites, hereby leading to the increase of crystallization rate of the as‐spun fiber. Meanwhile, it was found that the crystallinity of PP/OMMT hybrid fibers is much higher than that of pure PP fiber at the same draw ratios, whereas the orientation of PP/OMMT hybrid fibers is much lower than that of pure PP fiber at the same draw ratios. Because of the effective intercalation of OMMT into PP matrix, the nanocomposites have good spinnability, and the moisture absorption of the final PP fiber is improved. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 92: 552–558, 2004