Ultrasound assisted continuous‐mixing for the preparation of PP/SEBS/OMMT ternary nanocomposites

Polypropylene (PP)/polystyrene‐block‐poly(ethylene‐co‐butylenes)‐block‐polystyrene (SEBS)/organo‐montmorillonite (OMMT) nanocomposites of varying concentrations of maleic anhydride‐grafted polypropylene (PP‐g‐MA) were prepared by continuous mixing assisted by ultrasonic oscillation. The structure and morphology of nanocomposites were investigated by X‐ray diffraction (XRD), transmission electron microscopy, and scanning electron microscopy. It was found that both PP‐g‐MA and ultrasonic oscillation could enhance the intercalation and exfoliation of OMMT in PP matrix. Meanwhile, the formation of PP could be induced by ultrasonic irradiation at a power of more than 540 W. Rheological properties including complex viscosity, storage, and loss modulus of nanocomposites were increased after adding PP‐g‐MA or ultrasonic treatment. The results of mechanical properties showed that PP‐g‐MA could improve the tensile strength and tensile modulus of nanocomposites, but with the sacrifice of impact strength. This problem could be improved by ultrasound due to the reduced particle size of SEBS. However, the mechanical properties would be reduced by ultrasonic treatment with higher intensity due to the polymer degradation. Therefore, the synergistic effect of both compatibilizer and ultrasound should account for the balance between toughness and stiffness of PP/SEBS/OMMT ternary nanocomposites. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131, 41202.     

PP/PEO/OMMT复合材料微观形态及力学性能研究

通过熔融共混法制备了聚丙烯(PP)/聚氧化乙烯(PEO)/有机蒙脱土(OMMT)复合材料,采用透射电子显微镜(TEM)、扫描电子显微镜(SEM)和力学性能测试表征了该复合材料的微观形态和力学性能。结果表明:OMMT选择性分布在PEO中及PP、PEO两相边界处,PP中只有少量OMMT存在;随着OMMT含量的增加,PEO分散相尺寸逐渐减小,且分布均匀;PP/PEO/OMMT复合材料的拉伸强度随OMMT含量的增加呈增大趋势,缺口冲击强度在OMMT含量为3%时出现极大值4.379kJ/m2。     

PPO改性SEBS/PP共混体系压缩永久形变的研究

通过双螺杆挤出共混的方法制备了PPO改性SEBS/PP共混体系。研究了经PPO改性SEBS/PP共混体系的耐热性及压缩永久形变性能。研究结果表明,PPO可与SEBS中的PS相互容,形成玻璃化转变温度更高的新相区;PPO的加入在保持共混体系硬度、力学性能基本不变的情况下可明显改善SEBS/PP体系在高温下的压缩永久形变性能,当PPO质量分数为SEBS的15%~20%时,共混体系在70℃下的压缩永久形变值仅为33%~35%,小于50%,达到了车辆门窗橡胶密封条的国家标准。     

纳米有机蒙脱土改性SEBS/PP共混物的研究

通过熔融插层的方法将纳米有机蒙脱土（OMMT）与氢化苯乙烯-丁二烯-苯乙烯嵌段共聚物（SEBS）／聚丙烯（PP）共混制备得到SEBS／PP／OMMT复合材料。X射线衍射实验证明,复合材料SEBS／PP／OMMT5％、SEBS／PP／OMMT10％片层间距分别为4．17nm,3．91nm,说明聚合物插层进入OMMT片层之间,制备得到SEBS／PP／OMMT插层复合材料。采用锥形量热仪测试材料的阻燃性能,燃烧测试结果表明,SEBS／PP／OMMT复合材料具有比较低的热释放速率和质量损失速率,并且随着OMMT添加量增加,复合材料的热释放速率、峰值热释放速率和总热释放先显著降低最后趋于一个稳定值。综合力学测试结果表明,当有机蒙脱土质量分数为5％～10％时,该复合材料的综合性能最好。     

SEBS/蒙脱土纳米复合材料结构和性能研究

采用溶液混合方法制备了氢化苯乙烯/丁二烯三元嵌段共聚物(SEBS)/有机蒙脱土(OM-MT)纳米复合材料(NC)。对SEBS/OMMT NC的插层结构和物理力学、动态力学、耐热等性能进行了研究。结果表明,与SEBS复合,OMMT层间距明显增大,制备出具有插层型结构的NC。加入OMMT可明显提高SEBS的拉伸断裂强度、300%定伸强度和断裂伸长率,但永久变形也增大。DMA研究表明,SEBS/OMMT NC的储能模量和损耗模量比纯SEBS显著提高,PEB链段的tanδ降低,而PS链段增加。SEBS/OMMT NC比SEBS的热稳定性明显提高。     

SEBS／蒙脱土复合材料结构与阻燃性能的研究

根据蒙脱土（MMT）特殊的片层结构,采用熔融插层法制备热塑性弹性体SEBS／蒙脱土插层复合材料。通过X射线衍射仪、透射电镜等表征手段研究复合材料的微观结构。使用锥形量热仪评价复合材料的燃烧性能。结果表明,有机蒙脱土（OMMT）片层的间距为1．948nm,SEBS／5％OMMT体系的片层间距为4．307nm,说明聚合物SEBS插入有机蒙脱土片层之间。SEBS／OMMT复合材料具有较低的热释放速率和质量损失速率,且随着OMMT添加量的增加,其热释放速率峰值降低愈明显。通过对复合材料的阻燃性能和微观结构的分析,探讨了其阻燃机理。     

Effect of intercalation agent on the structure and properties of OMMT and RTV/OMMT composites

Novel room‐temperature vulcanized silicone rubber (RTV)/organic montmorillonite (OMMT) composites have been prepared. Di(2‐oxyethyl)‐12 alkane‐3 methyl‐amine chloride and hydrogen silicone oil were used as intercalation agents to treat Na⁺‐montmorillonite and form two kinds of OMMTs. The structure and properties of OMMT were characterized by Fourier transform infrared spectroscopy and X‐ray diffraction (XRD). The intercalation mechanism of different types of intercalation agents was proposed. RTV/OMMT composites were prepared using these OMMTs. Properties such as viscosity, hardness, tensile strength, elongation at break, and thermal stability were researched and compared. A combination of swelling test, XRD and transmission electronic microscopy studies was used to characterize the structure and reinforcing mechanism of these OMMTs. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012     

Mechanical and rheological properties of polypropylene/bentonite composites with stearic acid as an interface modifier

In this study, we present a study of polypropylene/bentonite composites where stearic acid was used as both a surface and interface modifier during the compounding of composites. The concentration of bentonite was 1.5, 2.5, 5.0, and 10 parts per hundred. The composites were characterized by impact resistance and tensile tests, rheological analysis, the dispersion state of the filler observed by optical microscopy, and interaction between bentonite and stearic acid, as analyzed by Fourier transform infrared spectroscopy. No chemical interaction was found between bentonite and stearic acid. Composites with modified bentonite and stearic acid used as interface modifiers increased the elongation at break; these samples also showed better dispersion of the filler in comparison with the other compounds. In addition, stearic acid acted as a lubricant, favoring the interaction of the polymer with the filler and decreasing the viscosity of the compounds. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 42264.     

纳米有机蒙脱土/聚丙烯复合材料性能与结构研究

采用双螺杆熔融混合造粒和单螺杆挤出制样的方法制备了纳米有机蒙脱土（OMMT）／PP复合材料。通过透射电子显微镜（TEM）及力学性能测试研究了复合材料的力学性能及纳米OMMT粒子的分散状况。结果表明,在纳米OMMT／PP复合体系中,纳米OMMT在基体中达到纳米级分散,同时,聚合物大分子链插入到纳米OMMT的层间,纳米OMMT的加入,不但使冲击强度显著提高,而且使弯曲弹性模量显著提高。     

Evaluation of mechanical properties of polypropylene/polycarbonate/SEBS ternary polymer blends using Taguchi experimental analysis

In this work, ternary polymer blends based on polypropylene (PP)/polycarbonate (PC)/poly(styrene‐b‐(ethylene‐co‐butylene)‐b‐styrene) (SEBS) triblock copolymer and a reactive maleic anhydride grafted SEBS (SEBS‐g‐MAH) at fixed compositions are prepared using twin‐screw extruder at different levels of die temperature (235‐245‐255°C), screw speed (70‐100‐130 rpm), and blending sequence (M1‐M2‐M3). In M₁ procedure, all of the components are dry blended and extruded simultaneously using Brabender twin‐screw extruder, whereas in M₂ procedure, PC, SEBS, and SEBS‐g‐MAH minor phases are first preblended in twin‐screw extruder and after granulating are added to PP continuous phase in twin‐screw extruder. Consequently, in M₃ procedure, PP and SEBS‐g‐MAH are first preblended and then are extruded with other components. The influence of these parameters as processing conditions on mechanical properties of PP/PC/SEBS ternary blends is investigated using L9 Taguchi experimental design. The responding variables are impact strength and tensile properties (Young's modulus and yield stress), which are influenced by the morphology of ternary blend, and the results are used to perform the analysis of mean effect as well. It is shown that the resulted morphology, tensile properties, and impact strength are influenced by extrusion variables. Additionally, the optimum processing conditions of ternary PP/PC/SEBS blends were achieved via Taguchi analysis. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010     

Study on morphology and viscoelastic properties of PP/PET/SEBS ternary blend and their fibers

The morphology development of polypropylene (PP)/polyethylene terephthalate (PET)/styrene‐ethylene‐butylene‐styrene (SEBS) ternary blends and their fibers were studied by means of scanning electron microscopy (SEM) in conjunction with the melt linear viscoelastic measurements. The morphology of the blends was also predicted by using Harkin's spreading coefficient approach. The samples varying in composition with PP as the major phase and PET and SEBS as the minor phases were considered. Although SEM of the binary blends showed matrix‐dispersed type morphology, the ternary blend samples exhibited a morphological feature in which the dispersed phase formed aggregates consisting of both PET and SEBS particles distributed in the PP matrix. The SEM of the blend samples containing 30 and 40 wt % of total dispersed phase showed an agglomerated structure formed between the aggregates. The SEM of the PP/PET binary fiber blends showed long well‐oriented microfibrils of PET whereas in the ternary blends, the microfibrils were found to have lower aspect ratio with a fraction of the SEBS stuck on the microfibril fracture surfaces. These results were attributed to a core‐shell type morphology in which the PET and SEBS formed the core‐shells distributed in the matrix. The melt viscoelastic behavior of the ternary blends containing less than 30 wt % of the total dispersed phase was found to be similar to the matrix and binary blend samples whereas the samples containing 30 and 40 wt % of dispersed phases exhibited a pronounced viscosity upturn and nonterminal storage modulus in low frequency range. These results were found to be in good agreement with the morphological results. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009     

溴化丁基橡胶/天然橡胶/有机蒙脱土纳米复合材料的结构与性能研究

采用机械混炼法制备了溴化丁基橡胶/天然橡胶/有机蒙脱土(BIIR/NR/OMMT)纳米复合材料,对其亚微观结构与性能进行了表征。实验结果表明:OMMT片层以剥离形式均匀分散于橡胶基体中;OMMT能够明显促进橡胶硫化反应,并使BIIR和NR两相的交联同步性加强;纳米复合材料具有优异的物理机械性能和热稳定性能。     

Study on the phase structures and toughening mechanism in PP/EPDM/SiO2 ternary composites

In this paper, EPDM rubber and nano-SiO₂ particles were employed to modify PP simultaneously. Our goal was to control the distribution and dispersion of EPDM and nano-SiO₂ particles in PP matrix by using an appropriate processing method and adjusting the wettability of nano-SiO₂ particles toward PP and EPDM, so as to achieve a simultaneous enhancement of toughness and modulus of PP. With regard to this, two kinds of nano-SiO₂ particles (with hydrophilic or hydrophobic) as well as two processing methods (one-step or two-step) were employed to prepare PP/EPDM/SiO₂ ternary composites. A unique structure with the majority of EPDM particles surrounded by SiO₂ particles was first observed by using hydrophilic SiO₂ and two-step processing method, resulting in a dramatically increase of Izod impact strength as the rubber content in the range of brittle-ductile transition (15-20 wt%). The observation that poor adhesion and poor compatibility between particles and PP matrix could result in a significant increase in Izod impact strength was unusual and needed further investigation. This could be tentatively understood as a consequence of the overlap of the ‘stress volume’ between EPDM and SiO₂ particles due to the formation of the unique structure. Our work provided a deep understanding of the toughening mechanism and a new way for the preparation of high performance polymer composites.     

SEBS弹性体对聚丙烯形貌、力学性能和结晶性能的影响

采用SEBS(氢化SBS)弹性体增韧PP.利用SEM、DSC、熔体指数、力学性能测试等研究不同SEBS含量的PP/SEBS共混物的力学性能、微观形态结构以及结晶性能.结果表明:SEBS可均匀分布在基体中,改善PP的加工流动性;SEBS的加入使得PP的球晶尺寸减小,结晶度降低;随着SEBS含量增加,共混物的冲击韧性有较大幅度的提高,而屈服强度略有下降:当加入25%的SEBS时,PP/SEBS共混物的冲击强度比纯PP提高近26倍,拉伸强度则仅仅降低23%.     

SEBS/PP共混材料的研究及其进展

SEBS是一种用途广泛的新型弹性体材料,在常温下具有高弹性,高温下可直接加工成型。由于SEBS具有优异的耐臭氧、耐氧化、耐紫外线和耐候性能等,因此,应用范围广于普通SBS材料。但是,SEBS耐溶剂性和耐油性较差,常通过与其他材料共混改性来增强其加工性能。文章重点概述了苯乙烯-乙烯-丁烯-苯乙烯(SEBS)与聚丙烯(PP)共混材料的微观结构、相容性以及结构与性能的研究进展,介绍了近年国内外SEBS/PP共混改性的研究成果,包括填充油、无机材料、PPO、PC和PA6等改性体系,并比较了这些改性技术对SEBS/PP共混体系微观结构及性能的影响,近年内,SEBS/PP共混材料的理论研究和工程应用会有长足发展。     

NBR/CR/OMMT纳米复合材料的结构与性能研究

采用机械混炼法制备了丁腈橡胶/氯丁橡胶/有机蒙脱土(NBR/CR/OMMT)纳米复合材料,并对其亚微观结构与性能进行了研究。透射电子显微镜(TEM)观察表明,OMMT以纳米尺寸分散于橡胶基体中,它与橡胶基体具有良好的相容性;OMMT能够明显提高纳米复合材料的表观交联密度;纳米复合材料具有优异的力学性能;与纯NBR/CR共混胶相比,纳米复合材料具有相同的起始分解温度和更高的最快失重温度。     

Mechanical properties and morphologies of PP/mPE/filler composites

Because of the poor impact behavior of polypropylene (PP) at low temperatures, the blending of PP with metallocene‐polymerized polyethylene (mPE) elastomers was investigated in this study. However, a reduced modulus of the overall blend was inevitable because of the addition to elastomers. To obtain a balance of the properties, we introduced rigid inorganic fillers to PP/mPE blends. The performance of the composites was characterized with tensile and Charpy notched impact tests, and the fracture morphology was examined with scanning electron microscopy. The results showed that the effects of fillers in a brittle matrix and in a ductile matrix were quantitatively different. For PP/mPE/filler ternary composites, the dependence of Young's modulus and yield strength on CaCO₃ content was not significant compared with that of PP/filler binary composites, whereas the elongation at break and tensile toughness at room temperature for PP/mPE/filler systems were more improved. The impact strength of the PP/mPE blends filled with untreated glass beads and CaCO₃ at a low temperature was lowered because of the weak interfacial bond. However, the values of the impact strength of the PP/mPE/filler composites at a low temperature remained at a high level compared with that of pure PP. In particular, a PP/mPE blend filled with surface‐treated kaolin had a higher low‐temperature impact toughness than the unfilled blend. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 83: 3029–3035, 2002; DOI 10.1002/app.2333     

Kenaf‐filled biodegradable composites: rheological and mechanical behaviour

Biodegradable polymer composites, typically based on biodegradable polymer matrices and natural‐organic fillers, are gaining rising interest and importance over the last few years. Several natural‐organic fillers can be used but the most widespread so far is wood, in the form of fibres or flour. Alternative cellulosic fillers can ensure advantages in terms of resource utilization and properties of the final composite. In this work, Mater‐Bi^® based biodegradable composites were prepared with two kinds of wood flour, and directly compared with alternative composites containing kenaf fibres. The use of kenaf fibres allowed improved elastic modulus, tensile strength and interaction with the polymer matrix to be obtained, although the filler dispersion was worse. Rheological measurements evidenced higher viscosity and an increasingly elastic behaviour of the melt. Copyright © 2012 Society of Chemical Industry     

Mechanical and thermal properties of polypropylene/modified basalt fabric composites

Basalt fabric (BF) was first treated with silane coupling agent KH550, modified basalt fabric (MBF) was obtained. Then MBF were molded with polypropylene (PP) matrix, and polypropylene/modified basalt fabrics (PP/MBF) composites were obtained. The influence of concentration and treating time of KH550 on MBF were characterized by hydrophilicity and lipophilicity. The tensile strength and morphology of basalt fabric were tested by single filament strength tester and scanning electron microscopy. The mechanical properties of composites were measured with electronic universal testing machine and impact testing machine, and the thermal properties were tested by thermogravimetric analysis and dynamic mechanical analysis. The results showed that the lipophilicity of MBF is improved significantly by KH550 while the tensile is nearly damaged. The mechanical properties of composites are larger than that of pure PP, among which the impact property was improved the most, showing 194.12% enhancement. The thermal stability and dynamic viscoelasticity were better than pure PP; furthermore, the concentration of KH550 virtually had no effect on the thermal stability. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 42504.     

PU／EP／PBA三元IPN弹性体的力学性能

测试了一系列以ＰＵ为第一网络的ＰＵ／ＥＰ／ＰＢＡ三元ＩＰＮ的力学性能,并详尽考究考察了其影响因素。通过研究,得到一类具有良好综合的弹性体,其拉伸强度和扯断伸长率可同时达到最佳值。研究表明,发迹合成条件,可达到控制调节材料性能的目的。第一网络的性质和组分间的相容性,是决定体系最终性能的两个重要方面。