固相法制备有机黏土改性聚丙烯

采用固相法对黏土进行有机化插层改性,制备出有机黏土;通过熔融插层法制备聚丙烯/有机黏土纳米复合材料。X射线衍射分析表明,固相法改性黏土可以与聚丙烯形成纳米复合材料。利用DSC研究了纳米复合材料的结晶和熔融过程,结果表明:聚丙烯/有机黏土纳米复合材料的结晶温度提高,熔融过程、熔点及结晶度没有明显变化。力学性能测试结果表明:有机黏土含量在3%～5%范围内,纳米复合材料的力学性能最佳。     

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。     

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。     

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。     

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。     

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。     

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。     

丁基橡胶/有机黏土纳米复合材料的结构和性能

采用溶液插层法制备了丁基橡胶／有机黏土纳米复合材料,并用透射电子显微镜和X射线衍射仪研究了该纳米复合材料的形态结构。结果表明,丁基橡胶／有机黏土纳米复合材料是插层型的纳米复合材料。与丁基橡胶相比,该纳米复合材料具有优异的力学性能和气体阻隔性能,并且这2种性能均随有机黏土用量的增加而增强。填料的形状会对该纳米复合材料的气体阻隔性能产生影响。     

PP/PP-g-MAH/OMMT纳米复合材料流变性能

采用自制聚丙烯(PP)接枝马来酸酐(PP-g-MAH)作为相容剂,与经有机化改性的蒙脱土(OMMT)通过熔融插层法制备了PP/PP-g-MAH/OMMT纳米复合材料,对其加工和流变性能进行了研究.结果发现,随着OMMT用量增加,PP/OMMT和PP-g-MAH/OMMT纳米复合材料的熔体流动速率(MFR)有下降的趋势;...     

相容剂对聚丙烯/纳米黏土复合材料抗熔垂性能影响的研究

在双螺杆挤出机上制备了相容剂马来酸酐接枝聚丙烯(PP-g-MAH)改性的聚丙烯(PP)纳米黏土复合材料。通过XRD测试和杭熔垂性能测试研究了PP-g-MAH对复合材料杭熔垂性能的影响。研究表明:PP-g-MAH的性能和用量对复合材料的插层结构有一定影响,进而影响到复合材料的杭熔垂性能.其中,采用熔体流动辣率小、接枝率低的PP-g-MAH所得到的纳米黏土复合材料的杭熔垂性能相对较奸,但PP-g-MAH的含量不宜过高。插层结构的黏土片层的层间距与复合材料杭熔垂性能存在一定关联,PP纳米黏土复合材料中存在最利于材料杭熔垂性能捍高的插层结构,层间距为2. 90-3. 10 nm的插层结构对应的复合材料的杭熔垂能力较好     

PP/PS-海泡石插层纳米复合材料的流变性能与形态结构

采用苯乙烯乳液聚合法对有机海泡石原位插层,将插层产物聚苯乙烯(PS)-海泡石与聚丙烯(PP)熔融共混制备PP/PS-海泡石插层纳米复合材料.流变测试结果表明:PP/PS-海泡石插层纳米复合材料为典型的假塑性流体,其偏离牛顿流体的程度随PS-海泡石含量增加而增大,表观黏度和零切黏度随着PS-海泡石含量的增加而减小,PS-...     

Thermal,mechanical, and rheological characterization of polypropylene/layered double hydroxide nanocomposites

Polypropylene (PP)/organomodified layered double hydroxide (LDH) nanocomposites were prepared in order to examine the influence of LDH content on thermal, mechanical, and rheological properties. The nanostructure examinations by X‐ray diffraction (XRD) and transmission electron microscopy (TEM) confirmed the exfoliated/intercalated dispersion of LDH. Incorporation of the LDH resulted in a noteworthy improvement in the thermal stability of PP. It was shown that the addition of LDH contributed to the reinforcement effect by increasing the elastic modulus. The mechanical performance, as evaluated by stress–strain curves, reveal that PP/LDH hybrid materials showed significant contribution toward increment in elastic modulus, tensile strength but at the expense of impact strength. The rheological response showed a strong influence of LDH particles on the flow behavior of the PP/LDH melt which resulted in enhancement of storage, loss of moduli, and complex viscosity of nanocomposites. Therefore, the nanocomposites have higher moduli but better processibility compared with pure PP. Overall, the results indicated that the LDH particles in nanometer size might act as potential reinforcing agent for polypropylene. POLYM. ENG. SCI., 52:2006–2014, 2012. © 2012 Society of Plastics Engineers     

Effects of polypropylene-g-(maleic anhydride/styrene) compatibilizer on mechanical and rheological properties of polypropylene/clay nanocomposites

To enhance the dispersibility of clay in polypropylene (PP) matrix, PP-g-(maleic anhydride/styrene) (MA/ST) was prepared as a compatibilizer by graft copolymerization of maleic anhydride (MA) and styrene (ST) with PP. The addition of ST was known to be effective in improving the graft degree. PP/clay nanocomposites with the compatibilizer were prepared by melt intercalation. The X-ray diffraction (XRD) peaks of (0 0 1) plane of the organo-modified montmorillonite (O-MMT) were shifted to lower angles by an addition of PP-g-(MA/ST), indicating the intercalation capability of PP-g-(MA/ST) in the silicate layers. Transmission electron microscopy (TEM) photographs showed that the O-MMT in the presence of PP-g-(MA/ST) was intercalated and partly exfoliated during melt mixing. The addition of O-MMT and PP-g-(MA/ST) improved the thermal stability, tensile and rheological properties of the nanocomposites.     

聚丙烯/有机累托石纳米复合材料制备及性能研究

采用阳离子交换反应法制备了有机累托石(OREC),在聚丙烯(PP)中添加马来酸酐接枝PP(PP-g-MAH)相容剂,通过熔融共混制备了PP/OREC以及PP/聚酰胺6(PA6)/OREC复合材料,对其进行了XRD、TEM表征和力学性能测试,结果表明:OREC能在PP中得到插层和一定程度的剥离;OREC在PP/PA6/OREC中的分散效果及对力学性能的改善要好于PP/OREC;PP-g-MAH的最佳加入量为9%~10%     

Preparation and characterization of polypropylene/layered silicate nanocomposites using an antioxidant

Polypropylene (PP)/layered silicate nanocomposites were prepared via simple melt mixing of three components, PP, layered silicates modified with octadecylamine (C18-MMT) and antioxidant, to investigate the role of antioxidant. TEM and X-ray scattering results confirmed the intercalated state of silicates in PP/layered silicate nanocomposites with antioxidant. In rheological and mechanical study, the nanocomposites with antioxidant showed higher properties than those of the unfilled PP. The nanocomposite with 5 wt% C18-MMT and 0.5 phr antioxidant exhibited about 1.4 times higher tensile modulus and 1.3 times higher storage modulus than the unfilled PP. However, PP/C18-MMT without antioxidant showed lower rheological values owing to the thermal decomposition of PP and the poor compatibility between PP and C18-MMT. It could be concluded that antioxidants played an important role in enhancing the compatibility between PP and C18-MMT. According to the real time X-ray diffraction, the nanocomposite showed the weak ordering of PP crystals than the unfilled PP in the load-extension plateau region of elongation.     

Solid‐state graft polymerization of styrene in spherical polypropylene particles in the presence of montmorillonite

In this work, cetyltrimethyl ammonium bromide and methacryloyloxyethyhrimethyl ammonium chloride were used to prepare organophilic montmorillonite (O‐MMT). Then, polypropylene (PP)–clay nanocomposites were prepared by the in situ grafting polymerization of styrene (St)‐containing O‐MMT onto PP with tert‐butyl perbenzoate as an initiator in the solid state. Fourier transform infrared spectroscopy, gel permeation chromatography, transmission electron microscopy, and X‐ray diffraction were applied to study the structure of the layered silicate and modified PP. The surfaces of the composites and, thus, the distribution of the clay in the PP matrix were characterized by scanning electron microscopy. The rheology and mechanical properties were studied and are discussed. According to the characterization results, OMMT and St were already grafted onto the PP main chain. Also, the intercalated structure of montmorillonite could be stabilized, and a stable exfoliated structure could be attained. Namely, intercalated PP/OMMT nanocomposites were obtained. The rheological results clearly show that these PP/OMMT nanocomposites had long‐chain‐branched structures. The peroxide modification of PP had minor effects on the tensile and bending strengths of the modified PP; however, this modification resulted in a significant reduction in the impact strength. © 2012 Wiley Periodicals, Inc. J Appl Polym Sci, 2012     

Influence of poly(ethylene glycol)/montmorillonite hybrids on the rheological behaviors and mechanical properties of polypropylene

The effects of poly(ethylene glycol) (PEG)/montmorillonite (MMT) hybrids on the phase morphology, rheological behaviors and mechanical properties of polypropylene (PP) were investigated. The analysis of transmission electron microscopy (TEM) and wide-angle X-ray diffraction (WAXD) indicated that the PEG modified montmorillonite was intercalated and well dispersed into PP matrix. It was found that the addition of the PEG/MMT hybrids in PP matrix lead to a significant reduction of melt viscosity and enhancement in izod-notched impact strength and elongation at break, except that the tensile strength was without much obvious change. A quantitative analysis indicated that MMT was intercalated by PEG, which was responsible for the melt viscosity reduction of PP matrix. Differential scanning calorimetry (DSC) analysis indicated that the addition of PEG/MMT hybrids induced the formation of β-crystal of PP. Polarized light micrographs (PLM) analysis indicated that the dispersed MMT, which acted as a nucleating agent, lowered the spherulite dimension and increased the spherulite number, resulting in high izod-notched impact strength and elongation at break.