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双单体原位接枝插层法制备聚丙烯纳米复合材料的研究Ⅰ.制备、表征及力学性能的研究 总被引:5,自引:0,他引:5
用有机插层剂处理蒙脱土原土 ,制得有机蒙脱土 (O MMT) .采用双单体 (马来酸酐和苯乙烯 )原位接枝插层法 ,制备了聚丙烯 蒙脱土纳米复合材料母料 .将母料与聚丙烯基体在双螺杆上共混挤出 ,制得聚丙烯 蒙脱土纳米复合材料 (PP Montmorillonetenanocomposites,PMNC) .这是制备聚合物纳米复合材料的一种新方法 .通过X 射线衍射测试 (XRD)表明 ,有机蒙脱土片层 0 0 1面间距从原土的 1 4 9nm扩大到 2 96nm ,复合材料中蒙脱土片层 0 0 1面间距由有机蒙脱土的 2 96nm扩大到 4 0nm .力学性能测试表明 ,复合材料的力学性能明显优于PP基体 ,在提高材料拉伸强度的同时 ,缺口冲击强度也得到很大的提高 .用扫描电镜 (SEM)对材料的冲击断面形貌进行了研究 ,并从理论上分析了断裂机理 .随着蒙脱土含量的增加 ,冲击断裂形式逐渐从脆性断裂变成韧性断裂 相似文献
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悬浮缩聚法制备酚醛树脂/蒙脱土纳米复合材料 总被引:13,自引:0,他引:13
采用悬浮缩聚方法在酸性催化剂作用下制备了酚醛树脂/蒙脱土纳米复合材料。以三种不同的蒙脱土:天然土、带有脂肪链季铵盐修饰蒙脱土和带有苯环基团的插层剂修饰的蒙脱土为原料制备了纳米复合材料,并考察了不同插层剂对纳米复合材料形貌的影响,发现带有苯环的插层剂修饰的蒙脱土与酚醛树脂的相容性能更好;研究了固化过程对纳米复合材料形貌的影响,XRD和TEM的结构表明固化过程可以促进带有脂肪链季铵盐修饰的蒙脱土进一步剥离,对其他两类的影响不大;此外还用TGA研究了纳米复合材料的热性能。 相似文献
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丙烯酸树脂/蒙脱土纳米复合材料的制备研究 总被引:3,自引:1,他引:2
采用离子交换法,用十六烷基三甲基溴化铵对钠基蒙脱土(Na-MMT)进行改性制备了有机蒙脱土(OMMT).用丙烯酸(AA)、硫酸化蓖麻油、乳化剂OP-10、过硫酸钾为原料进行水溶液聚合制得丙烯酸树脂.将丙烯酸树脂与改性蒙脱土通过聚合插层制备了丙烯酸树脂/ 蒙脱土纳米复合材料.通过傅立叶变换红外(FTIR)和X-射线衍射 (XRD)等手段对复合材料的结构进行了表征,结果表明:丙烯酸树脂插层进入有机蒙脱土内可形成插层型或剥离型的纳米复合材料.蒙脱土含量及蒙脱土与丙烯酸树脂的反应温度、反应时间均对复合材料的剥离行为产生影响,在蒙脱土含量为树脂固含量的7%、温度为70℃、反应4h的条件下可得到完全剥离的纳米复合材料. 相似文献
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为了制备聚丙烯/蒙脱土纳米复合材料,将Brookhart型的乙烯齐聚催化剂负载于有机蒙脱土片层间,进一步与丙烯聚合茂金属催化剂进行复配得到双功能催化体系。采用这种双功能催化剂体系通过催化乙烯齐聚得到α-烯烃/蒙脱土的齐聚产物,进一步将丙烯与这种齐聚产物共聚,合成了一系列结构不同的聚丙烯/蒙脱土纳米复合材料。通过气相色谱、X射线衍射(XRD)分析得出蒙脱土负载的铁系催化剂催化乙烯齐聚产物是以C_4~C_(16)为主的α-烯烃,蒙脱土以片层形式分散于齐聚产物的甲苯溶液中。研究了蒙脱土负载的铁系催化剂与共聚催化剂复配催化乙烯齐聚以及丙烯与齐聚产物共聚合的情况。通过XRD、透射电镜、差示量热分析、凝胶渗透色谱分析表征可知,蒙脱土以纳米片层剥离的形式均匀分散于聚丙烯基体中,聚丙烯/复合材料的结晶温度比纯聚丙烯有所下降,所得聚丙烯基体分子量在8.1×10~4~17.1×10~4g/mo L。 相似文献
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将有机化的蒙脱土与尼龙6(PA6)在Haake共混机中共混,制备出尼龙6/蒙脱土纳米复合材料(PA6N);对尼龙6/蒙脱土纳米复合材料和纯尼龙6分别进行差示扫描量热法非等温结晶试验,以了解蒙脱土在尼龙6/蒙脱土纳米复合材料中的成核作用、扩大尼龙6在包装领域的应用范围.与此同时,采用偏光显微镜测定了样品的结晶形态;采用紫... 相似文献
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Graeme Moad Katherine Dean Lex Edmond Natalia Kukaleva Guoxin Li Roshan T A Mayadunne Rudolf Pfaendner Armin Schneider George Simon Hendrik Wermter 《Macromolecular Symposia》2006,233(1):170-179
The use of various copolymers as dispersants/intercalants/exfoliants in polypropylene (PP)-clay nanocomposites based on unmodified montmorillonite clays (NaMMT) has been explored. The primary objective of this research has been to find dispersants that allow PP nanocomposites to be formed by direct melt mixing, that are effective with unmodified clays and that comprise only a minor component of the overall composition both with respect to both clay and PP. Two classes of dispersants were investigated: PEO-based nonionic surfactants and amphiphilic copolymers based on a long chain (meth)acrylate (e.g. octadecyl acrylate) and a more polar comonomer (e.g. maleic anhydride, N-vinylpyrrolidone, methyl methacrylate). The state of dispersion achieved and the properties of the derived nanocomposites were found to depend strongly on both on the level of dispersant and its overall composition but interestingly properties are not particularly dependent on the dispersant architecture (i.e. whether statistical, gradient or block copolymer). The nanocomposites possess a tensile modulus up to 40% greater that the precursor PP while elongation at break and impact strength are significantly improved over “clay alone” composites and reference organoclay-based nanocomposites. Also notable are significantly better thermal and thermo-oxidative stability as compared to both PP and “clay alone” composites. For optimal properties, it is both necessary and desirable that the surfactant should only be a minor constituent (20–50 wt-%) of the composition with respect to clay. 相似文献
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Jeng‐Yue Wu Tzong‐Ming Wu Wei‐Yan Chen Shih‐Jung Tsai Wen‐Faa Kuo Gwo‐Yang Chang 《Journal of Polymer Science.Polymer Physics》2005,43(22):3242-3254
X‐ray diffraction and differential scanning calorimeter (DSC) methods have been used to investigate the crystallization behavior and crystalline structure of hexamethylenediamine (HMDA)‐modified maleic‐anhydride‐grafted polypropylene/clay (PP‐g‐MA/clay) nanocomposites. These nanocomposites have been prepared by using HMDA to graft the PP‐g‐MA (designated as PP‐g‐HMA) and then mixing the PP‐g‐HMA polymer in hot xylene solution, with the organically modified montmorillonite. Both X‐ray diffraction data and transmission electron microscopy images of PP‐g‐HMA/clay nanocomposites indicate that most of the swellable silicate layers are exfoliated and randomly dispersed into PP‐g‐HMA matrix. DSC isothermal results revealed that introducing 5 wt % of clay into the PP‐g‐HMA structure causes strongly heterogeneous nucleation, which induced a change of the crystal growth process from a three‐dimensional crystal growth to a two‐dimensional spherulitic growth. Mechanical properties of PP‐g‐HMA/clay nanocomposites performed by dynamic mechanical analysis show significant improvements in the storage modulus when compared to neat PP‐g‐HMA. © 2005 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 43: 3242–3254, 2005 相似文献
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Sedigheh Bagheri‐Kazemabad Daniel Fox Yanhui Chen Hongzhou Zhang Biqiong Chen 《先进技术聚合物》2014,25(10):1116-1121
The influence of nanoclay on the morphology and properties of the polypropylene (PP)/ethylene–octene block copolymer (EOC) blend with double compatibilizers of maleated PP (PP‐g‐MA) and maleated EOC (EOC‐g‐MA) was investigated and compared with the nanocomposites containing either PP‐g‐MA or EOC‐g‐MA as a compatibilizer. X‐ray diffraction, transmission electron microscopy, and scanning electron microscopy were utilized for morphological characterization in conjunction with dynamic mechanical thermal analysis, mechanical testing, and rheological evaluation of these nanocomposites. The results suggested that in the nanocomposite including both compatibilizers of PP‐g‐MA and EOC‐g‐MA, clay was dispersed as a mixed structure of intercalation and exfoliation in both phases of the polymer blend. Comparing the mechanical properties of the studied nanocomposite with nanocomposites of PP/EOC/PP‐g‐MA/clay and PP/EOC/EOC‐g‐MA/clay also indicated that the nanocomposite containing mixed compatibilizers displayed higher tensile modulus, tensile strength, and complex viscosity because of the better dispersion of clay in both phases. The results also confirmed the increased structural stability and reduced dispersed phase size of PP/EOC/PP‐g‐MA/EOC‐g‐MA blend in the presence of clay that proposed the compatibilization role of clay in this nanocomposite. Copyright © 2014 John Wiley & Sons, Ltd. 相似文献
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Polypropylene (PP)/Montmorillonite (MMT) nanoclay based composite was prepared by melt compounding with maleic anhydride grafted polypropylene (MA-g-PP) as a compatibilizer in a twin-screw extruder, and the test specimens were injection molded. Mechanical properties such as tensile modulus, flexural modulus, yield strength and maximum percent strains were measured for pure PP and PP based nanocomposite to establish the effect of clay platelet reinforcement. The fracture properties were measured by using the essential work of fracture (EWF) method. PP/clay nanocomposite shows 25% improvement in specific EWF compared to pure PP. The variation of EWF parameters with loading rate is discussed, whilst the mechanisms of fracture are considered in a subsequent paper. 相似文献
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纳米CaCO_3/相容剂/PP中的界面相互作用研究 总被引:1,自引:0,他引:1
采用不同相容剂(PP-g-MAH、POE-g-MAH和EVA-g-MAH)制备了不同界面相互作用的纳米CaCO3(CC)/相容剂/PP体系,研究了相容剂/PP和相容剂/CC界面相互作用对PP/CC的结晶形态、结晶行为、熔融特性和力学性能的影响.观察到PP/CC界面相互作用提高PP结晶温度和PP/CC的模量和冲击强度,但降低了屈服强度.相容剂/CC界面相互作用进一步提高了PP/CC的结晶温度.PP/相容剂界面相互作用取决于PP与相容剂相容性.PP/PP-g-MAH相容性高有利于提高PP/CC的异相成核作用和PP/CC屈服强度和模量,但降低冲击强度.PP/POE-g-MAH部分相容对相容剂/CC界面的异相成核作用、PP/CC屈服强度和模量影响不大,可明显提高冲击强度.但PP/EVA-g-MAH不相容导致PP/CC冲击强度明显降低. 相似文献
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Polypropylene (PP)-montmorillonite nanocomposites have been prepared using isotactic PP homopolymers with different rheological properties, and a maleic anhydride grafted PP. Morphology and structure of the composites were investigated by using X-ray techniques (WAXD, SAXS) and transmission electron microscopy (TEM). The absence of pristine clusters of the clay and the presence of intercalated and exfoliated structures were shown for all the investigated samples. The nanocomposite prepared by using maleic anhydride grafted PP showed a widespread exfoliation. The thermal behaviour and degradation have been studied by means of differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA). The incorporation of the montmorillonite improves the thermal stability in air atmosphere of all the investigated PPs, thanks to a physical barrier effect of the silicate layers. 相似文献
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Poly(propylene)/clay nanocomposites were prepared by melt intercalation, using pristine montmorillonite (MMT), hexadecyl trimethyl ammonium bromide (C16), poly(propylene) (PP) and maleic acid (MA) modified PP (MAPP), The nanocomposites structure is demonstrated using X‐ray diffraction (XRD) and high resolution electronic microscopy (HREM). Our purpose is to provide a general concept for manufacturing polymer nanocomposites by melt intercalation starting from the pristine MMT. We found different kneaders (twin‐screw extruder or twin‐roll mill) have influence on the morphology of the PP/clay nanocomposites. Thermogravimetric analysis (TGA) shows that the thermal stability of PP/clay nanocomposites has been improved compared with that of pure PP. Copyright © 2003 John Wiley & Sons, Ltd. 相似文献
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PREFERENTIAL INTERCALATION BEHAVIOR OF CLAY AND ITS EFFECT ON THE THERMAL DEGRADATION IN IMMISCIBLE PP/PS BLENDS 总被引:1,自引:0,他引:1
The typical immiscible PP/PS blend based clay nanocomposites were prepared via melt blending.The dispersion of clay was determined by X-ray diffraction (XRD) and transmission electron microscopy (TEM).Thermal stability and dynamic mechanical properties were measured by thermogravimetrical analysis (TGA) and dynamic mechanical analysis (DMA),respectively.Preferential intercalation behavior of clay in PP/PS blends was found.The dispersion of clay is significantly influenced by the polarity of PP and PS,mea... 相似文献
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The effects of reprocessing cycles on the structure and properties of isotactic polypropylene/cloisite 15A nanocomposites 总被引:2,自引:0,他引:2
Naima TouatiMustapha Kaci Stéphane Bruzaud Yves Grohens 《Polymer Degradation and Stability》2011,96(6):1064-1073
The effects of reprocessing cycles on the structure and properties of isotactic polypropylene (PP)/Cloisite 15A (OMMT) (5 wt. %) nanocomposites was studied in presence of maleic anhydride-grafted-polypropylene (PP-g-MA) (20 wt. %) used as the compatibiliser to improve the clay dispersion in the polymer matrix. The various nanocomposite samples were prepared by direct melt intercalation in an internal mixer, and further they were subjected to 4 reprocessing cycles. For comparative purposes, the neat PP was also processed under the same conditions. The nanocomposite structure and the clay dispersion have been characterized by wide angle X-ray scattering (WAXS), transmission electron microscopy (TEM) and rheological measurements. Other characterization techniques such as Fourier transform infrared spectroscopy (FT-IR), tensile measurements, differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA) have also been used to evaluate the property changes induced by reprocessing. The study showed through XRD patterns that the repetitive reprocessing cycles modified the initial morphology of PP/OMMT nanocomposites by improving the formation of intercalated structure, especially after the fourth cycle. Further, the addition of PP-g-MA promoted the development of intercalated/exfoliated silicate layers in the PP matrix after the second cycle. These results are in agreement with TEM observations indicating an improved silicate dispersion in the polymer matrix with reprocessing cycles displaying a morphology with both intercalated/exfoliated structures. The initial storage modulus (G′) of the nanocomposites, which was highly improved in presence of PP-g-MA seems to be less affected by reprocessing cycles at very low frequencies exhibiting a quasi-plateau compared to pristine PP/OMMT and PP. In contrast, the complex viscosity was found to decrease for the whole samples indicating that the main effect of reprocessing was a decrease in the molecular weight. Moreover, the thermal and mechanical properties of the nanocomposites were significantly reduced after the first cycle; nevertheless they remained almost unchanged during recycling. No change in the chemical structure was observed in the FT-IR spectra for both the nanocomposites and neat PP samples after 4 cycles. 相似文献
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动态固化聚丙烯/环氧树脂共混物的研究 总被引:3,自引:0,他引:3
将动态硫化技术应用于热塑性树脂 热固性树脂体系 ,制备了动态固化聚丙烯 (PP) 环氧树脂共混物 .研究了动态固化PP 环氧树脂共混物中两组分的相容性、力学性能、热性能和动态力学性能 .实验结果表明 ,马来酸酐接枝的聚丙烯 (PP g MAH)作为PP和环氧树脂体系的增容剂 ,使分散相环氧树脂颗粒变细 ,增加了两组分的界面作用力 ,改善了共混物的力学性能 .与PP相比 ,动态固化PP 环氧树脂共混物具有较高的强度和模量 ,含 5 %环氧树脂的共混物拉伸强度和弯曲模量分别提高了 30 %和 5 0 % ,冲击强度增加了 15 % ,但断裂伸长率却明显降低 .继续增加环氧树脂的含量 ,共混物的拉伸强度和弯曲模量增加缓慢 ,冲击强度无明显变化 ,断裂伸长率进一步降低 .动态力学性能分析 (DMTA)表明动态固化PP 环氧树脂共混物是两相结构 ,具有较高的储能模量 (E′) 相似文献