Morphology,thermal and mechanical behavior of polypropylene nanocomposites toughened with poly(ethylene‐co‐octene)

Rubber‐toughened polypropylene (PP) nanocomposites containing organophilic layered silicates were prepared by means of melt extrusion at 230 °C using a co‐rotating twin‐screw extruder in order to examine the influence of the organoclay and the addition of PP grafted with maleic anhydride (PPgMAH) as a compatibilizer on the morphological, mechanical and thermal properties. The mechanical properties of rubber‐toughened polypropylene nanocomposites (RTPPNCs) were studied through tensile, flexural and impact tests. Scanning electron microscopy (SEM) was used for investigation of the phase morphology and rubber particles size. X‐ray diffraction (XRD) was employed to characterize the formation of nanocomposites. The thermal properties were investigated by using thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC). The dynamic mechanical properties were examined by using dynamic mechanical analysis (DMA). From the tensile and flexural tests, the optimum loading of organoclay in RTPP was found to be 6 wt%. The optimum loading of PPgMAH, based on the tensile and flexural properties, was also 6 wt%. The increase in the organoclay and PPgMAH content resulted in a severe embrittlement, manifested by a drop in the impact strength and tensile elongation at break. XRD studies revealed that intercalated RTPPNCs had been successfully prepared where the macromolecular PP segments were intercalated into the interlayer space of the organoclay. In addition, the organoclay was dispersed more evenly in the RTPPNC as the PPgMAH content increased. TGA results revealed that the thermal stability of the RTPPNC improved significantly with the addition of a small amount of organoclay. Copyright © 2006 Society of Chemical Industry     

Effect of clay modification on the morphological,mechanical, and thermal properties of polyamide 6/polypropylene/montmorillonite nanocomposites

Polyamide 6/polypropylene (PA6/PP = 70/30 parts) blends containing 4 phr (parts per hundred resin) of organophilic montmorillonite (OMMT) were prepared by melt compounding. The sodium montmorillonite (Na‐MMT) was modified using three different types of alkyl ammonium salts, namely dodecylamine, 12‐aminolauric acid, and stearylamine. The effect of clay modification on the morphological and mechanical properties of PA6/PP nanocomposites was investigated using x‐ray diffraction (XRD), transmission electron microscopy (TEM), tensile, flexural, and impact tests. The thermal properties of PA6/PP nanocomposites were characterized using thermogravimetric analysis (TGA), dynamic mechanical analysis (DMA), and heat distortion temperature (HDT). XRD and TEM results indicated the formation of exfoliated structure for the PA6/PP nanocomposites prepared using stearylamine modified montmorillonite. On the other hand, a mixture of intercalated and exfoliated structures was found for the PA6/PP nanocomposites prepared using 12‐aminolauric acid and dodecylamine modified montmorillonite. Incorporation of OMMT increased the stiffness but decreased the ductility and toughness of PA6/PP blend. The PA6/PP nanocomposite containing stearylamine modified montmorillonite showed the highest tensile, flexural, and thermal properties among all nanocomposites. This could be attributed to better exfoliated structure in the PA6/PP nanocomposite containing stearylamine modified montmorillonite. The storage modulus and HDT of PA6/PP blend were increased significantly with the incorporation of both Na‐MMT and OMMT. The highest value in both storage modulus and HDT was found in the PA6/PP nanocomposite containing stearylamine modified montmorillonite due to its better exfoliated structure. POLYM. COMPOS., 31:1156–1167, 2010. © 2009 Society of Plastics Engineers     

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     

Study on the Effect of Polypyrrole and Polypyrrole/Graphene Oxide Nanoparticles on the Microstructure,Electrical and Tensile Properties of Polypropylene Nanocomposites

In this article Polypropylene/Polypyrrole (PP/PPy) and Polypropylene/polypyrrole-graphene oxide (PP/PPy-GO) nanocomposites were prepared by melt mixing. PPy nanoparticles and PPy-GO nanocomposite were prepared by chemical polymerization and served as nanofillers. FTIR, XRD and SEM analysis were used for the characterization of PPy and PPy-GO composites. The effects of PPy and PPy-GO loading level on the morphology, tensile and electrical properties of PP-based nanocomposites were examined. It was found that the Young's modulus and tensile strength increased with the increase of nanofiller content. Tensile results also showed that PPy-GO composite significantly affected the mechanical properties of PP based nanocomposites compared to the PPy nanoparticles. It was observed that the addition of 1% wt. PPy-GO into PP, increased the Young's modulus about 30% compared as with pure PP. Electrical conductivity measurements showed that conductivity of PP nanocomposites increased up to 1 × 10^?3 S/cm for PP/PPy-GO nanocomposites. It was also observed that PP-g-MA improved the distribution of PPy and PPy-GO nanocomposites and affected the morphology, electrical and mechanical properties of PP-based nanocomposites.     

纳米SiO_2增加聚丙烯(PP)的研究

通过熔融共混法制备了聚丙烯(PP)／SiO_2纳米复合材料,并使用扫描电镜(SEM)、电子拉力机和冲击机等对材料进行表征。研究发现硅烷偶联剂对纳米SiO_2在聚丙烯(PP)中的分散起一定的作用,但不是非常有效。添加相容剂PP-g-MAH后,可以使纳米SiO_2均匀地分散于PP中。当纳米SiO_2含量为2重量份时,PP／SiO_2纳米复合材料的性能最优,与纯PP相比较,Izod冲击强度提高了90％,拉伸强度略微提高了5％,弯曲强度提高了23%。最后,作者对纳米SiO_2的增韧机理和PP-g-MAH大幅度改善纳米SiO_2在PP中分散效果的机理作了初步推断。     

PA6／OMMT／SiO2纳米复合材料的制备及力学性能研究

以天然蒙脱土为原料，11-氨基酸作为有机插层剂与蒙脱土层间的阳离子进行交换制备OMMT，用原位聚合法制备PA6／OMMT／SiO2纳米复合材料，用X射线衍射仪、FT-IR光谱仪、差示扫描量热仪等对OMMT、纳米复合材料的结构及力学性能进行表征。结果发现，添加3％（质量含量，下同）OMMT的PA6／OMMT复合材料的拉伸强度、弯曲强度和弯曲模量较纯PA6分别提高了19％、13．8％、14％；而纳米SiO2的加入使纳米复合材料的拉伸和弯曲强度、刚性和韧性得到提高的同时，明显改善了蒙脱土使纳米复合材料缺口冲击强度下降的趋势，当纳米SiO2含量为1％时，缺口冲击强度提高了近33．5％。     

Regenerated cellulose/layered double hydroxide nanocomposite films with improved mechanical property

Construction of environment-friendly biomass-based nanocomposites with high performance is in great demand for developing of a sustainable low-carbon society. Here, transparent and flexible regenerated cellulose (RC)/layered double hydroxide (LDH) nanocomposite films were prepared from aqueous NaOH/urea solutions. The obtained nanocomposite films were characterized using AFM, SEM, FTIR, XRD, tensile testing, water contact angle, and thermogravimetric analysis. The results show that LDH nanoplatelets were individually dispersed with a thickness of 1 nm and surface diameter of 100 nm after ultrasonic treatment. Strong interaction existed between LDH nanoplatelets and cellulose molecules, leading to the improved thermal stability and mechanical strength of RC together with the original good properties of LDH. In particular, the nanocomposite films with 10 wt% LDH showed a 135% and 234% increase in the tensile strength and Young's modulus than those of the neat RC film. Meanwhile, the nanocomposite films exhibited high transparency. Therefore, these RC/LDH nanocomposites are promising in the fields of high-performance packaging materials, flexible display panels, and high-temperature dielectric materials.     

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。     

Study on Morphology,Rheology and Mechanical Properties of Thermoplastic Elastomer Polyolefin (TPO)/Carbon Nanotube Nanocomposites with Reference to the Effect of Polypropylene-grafted-Maleic Anhydride (PP-g-MA) as a Compatibilizer

The structure–property relationships of polypropylene/ethylene-propylene-diene (PP/EPDM) (80/20) nanocomposites containing single-walled carbon nanotubes (SWCNTs) by melt-mixing process were investigated, the main focus being on the effect of SWCNTs concentration and compatilizer content. Morphological observations by scanning electron microscopy (SEM) are presented in conjunction with the mechanical, thermal, and rheological properties of these nanocomposites. The tensile modulus of nanocomposites was enhanced by increasing the SWCNTs concentration. A high level of toughness in the thermoplastic elastomer polyolefin (TPO)/SWCNTs nanocomposite was achieved with 0.5 wt% of SWCNTs and 1 wt% of polypropylene-grafted maleic anhydride (PP-g-MA). Differential scanning calorimetry (DSC) experiments confirmed the nucleation effect of nanotubes on the crystallization process of the TPO/SWCNTs composites. An appreciable viscosity upturn and a non-terminal low frequency storage modulus were observed in nanocomposites containing SWCNTs whose values increased in the presence of compatibilizer.     

Morphological,Thermal and Mechanical Properties of Polypropylene and Vermiculite Blends

Morphological, thermal and mechanical properties of blends prepared from polypropylene (PP) and 1, 3 and 5 wt% of vermiculite (VMT) were studied. The samples were prepared in a twin-screw extruder. The addition of maleic anhydride-functionalized polypropylene (PP-g-MAH) was also investigated. The blend morphologies were determined by X-ray diffraction (XRD) and scanning electron microscopy (SEM). The thermal properties of the composites were investigated by differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA). The DSC results showed that PP crystallizes on cooling at higher temperatures as VMT content increases. The increase in crystallization temperature was most evident for blends with 5 wt% VMT. The TGA results showed that the use of VMT particles to fill polypropylene increased the thermal stability of the composite. The mechanical properties, tensile modulus and tensile strength at yield point of the PP improved by the presence of VMT.     

Influence of organically modified nanoclay on the performance of pineapple leaf fiber‐reinforced polypropylene nanocomposites

Polypropylene/Pine apple leaf fiber (PP/PALF)‐reinforced nanocomposites were fabricated using melt blending technique in a twin‐screw extruder (Haake Rheocord 9000). Variation in mechanical properties, crystallization behavior, water absorption, and thermal stability with the addition of nanoclay in PP/PALF composites were investigated. It was observed that the tensile, flexural, and impact properties of PP increase with the increase in fiber loading from 10 to 30 wt %. Composites prepared using 30 wt % PALF and 5 wt % MA‐g‐PP exhibited optimum mechanical performance with an increase in tensile strength to 31%, flexural strength to 45% when compared with virgin PP. Addition of nanoclay results in a further increase in tensile and flexural strength of PP/PALF composites to 20 and 24.3%, which shows intercalated morphology. However, addition of nanoclay does not show any substantial increase in impact strength when compared with PP/PALF composites. Dynamic mechanical analysis tests revealed an increase in storage modulus (E′) and damping factor (tan δ), confirming a strong influence between the fiber/nanoclay and MA‐g‐PP. Differential scanning calorimetry, thermogravimetric analysis thermograms also showed improved thermal properties when compared with the virgin matrix. TEM micrographs also showed few layers of agglomerated clay galleries along with mixed nanomorphology in the nanocomposites. Wide angle X‐ray diffraction studies indicated an increase in d‐spacing from 22.4 Å in Cloisite 20A to 40.1 Å in PP/PALF nanocomposite because of improved intercalated morphology. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009     

Mechanical,thermal and dynamic‐mechanical behavior of banana fiber reinforced polypropylene nanocomposites

Natural fiber‐reinforced nanocomposites based on polypropylene/nanoclay/banana fibers were fabricated by melt mixing in a twin‐screw extruder followed by compression molding in this current study. Maleic anhydride polypropylene copolymer (MA‐g‐PP) was used as a compatibilizer to increase the compatibility between the PP matrix, clay, and banana fiber to enhance exfoliation of organoclay and dispersion of fibers into the polymer matrix. Variation in mechanical, thermal, and physico‐mechanical properties with the addition of banana fiber into the PP nanocomposites was investigated. It was observed that 3 wt% of nanoclay and 5 wt% of MA‐g‐PP within PP matrix resulted in an increase in tensile and flexural strength by 41.3% and 45.6% as compared with virgin PP. Further, incorporation of 30 wt% banana fiber in PP nanocomposites system increases the tensile and flexural strength to the tune of 27.1% and 15.8%, respectively. The morphology of fiber reinforced PP nanocomposites has been examined by using scanning electron microscopy and transmission electron microscopy. Significant enhancement in the thermal stability of nanocomposites was also observed due to the presence of nanoclay under thermogravimetric analysis. Dynamic mechanical analysis tests revealed an increase in storage modulus (E′) and damping factor (tan δ), conforming the strong interaction between nanoclay/banana fiberand MA‐g‐PP in the fiber‐reinforced nanocomposites systems. POLYM. COMPOS., © 2011 Society of Plastics Engineers.     

Influence of reactive compatibilization on the structure and properties of PP/LDH nanocomposites

Polypropylene (PP)/layered double hydroxide (LDH) nanocomposites were prepared by the direct melt intercalation method using maleic anhydride grafted polypropylene (PP‐g‐MAH) as a reactive compatibilizer. The compatibilization effects provided by PP‐g‐MAH in different weight fractions and their influence on the structure and properties of the final nanocomposites were investigated. The interactions and structural morphology of the nanocomposites were examined by Fourier transform infrared spectroscopy, X‐ray diffraction and transmission electron microscopy. Thermal, mechanical and rheological properties of these nanocomposites were investigated as a function of compatibilizer concentration. The detailed morphological and X‐ray diffraction results revealed that the degree of LDH dispersion increases as the amount of PP‐g‐MAH increases. Study of the linear viscoelastic properties showed that the storage modulus G′ is very sensitive to the microstructure of the nanocomposite. The thermal properties of the nanocomposites were significantly influenced by the weight fraction of PP‐g‐MAH due to the shielding and nucleating effect of exfoliated layers. Both the tensile strength and modulus showed substantial improvements with increasing PP‐g‐MAH content, while the elongation at break substantially decreased, although the presence of PP‐g‐MAH somewhat improves these values. The overall results showed that 10 wt% of compatibilizer is optimum to achieve nanocomposites with better performance. Copyright © 2011 Society of Chemical Industry     

尼龙12/OMMT纳米复合粉末的制备及性能

利用十八烷基三甲基溴化铵(OTAB)对蒙脱土(MMT)进行有机改性,并通过溶液插层法制备尼龙12/有机蒙脱土(PA12/OMMT)纳米复合粉末。利用X射线衍射、傅立叶变换红外光谱、扫描电子显微镜等手段对改性后的MMT及PA12/OMMT纳米复合粉末的结构和微观形貌进行表征,并将复合粉末热压成型制成标准件,测试其力学性能和热性能。结果表明,经过有机改性,MMT的层间距由1.24 nm增加到了2.13 nm,且改性后的MMT能均匀地分散在PA12基体中,PA12/OMMT纳米复合粉末的成型件在拉伸强度、弯曲强度、冲击强度和热性能方面都优于纯PA12粉末。PA12/OMMT纳米复合粉末为选择性激光烧结技术(SLS)提供了一种性能良好的粉末材料。     

Mechanical,thermal, and morphological properties of graphene reinforced polycarbonate/acrylonitrile butadiene styrene nanocomposites

Nanocomposites of polycarbonate/acrylonitrile butadiene styrene (PC/ABS) with (70/30) composition containing different amounts of graphene nanoplates (GNPs) (1, 3, and 5 wt%) were prepared by melt‐blending in a twin‐screw extruder. The structural, morphological, mechanical, and thermal properties of the nanocomposites were investigated. The Young's modulus and flexural modulus of the nanocomposites were increased by 30 and 54%, respectively, when 3 wt% GNPs was added. The flexural strength and tensile strength of the PC/ABS/GNPs nanocomposites increased up to a loading of 3 wt% GNPs. The incorporation of GNPs enhanced the thermal stability and char yield of the nanocomposites. X‐ray diffraction and field emission scanning electron microscopy showed uniform dispersion and alignment of GNPs in PC/ABS matrix. The interaction between the GNPs and the PC/ABS matrix were confirmed by Fourier transform infrared spectra. Therefore, the PC/ABS/GNP nanocomposites with improved flexural and tensile properties, without loss of extensibility and good thermal properties may have promising applications in automotive, electric tools, household, communication, and safety appliances. POLYM. COMPOS., 37:1633–1640, 2016. © 2014 Society of Plastics Engineers     

Influence of graphene-based compounds on the mechanical toughness and thermal stability of polypropylene

A study of the improvement of the mechanical and thermal properties of nanocomposites prepared with polypropylene (PP) and different graphene samples [graphene oxide (GO), reduced GO (RGO), and commercial graphene (G)] is presented. X-ray diffraction (XRD) and X-ray photoelectron spectroscopy characterization were applied to the graphene samples. The nanocomposites were characterized by thermogravimetric analysis, XRD, differential scanning calorimetry, transmission electron microscopy (TEM), tensile, and impact resistance tests. PP/RGO nanocomposites showed significant improvement in mechanical and thermal properties. Sample PP/RGO-0.75 resulted in an increment in Young's modulus (51%), tensile strength (24%), and elongation at break (15%). This is attributed to a good dispersion state, a higher crystallinity percentage, and a good interfacial adhesion between PP and RGO. Sample PP/RGO-0.50 exhibited an increase of 197 °C in the temperature at which a loss in weight of 5% occurred, compared to that for pure PP. The height of stacked layers calculated by XRD measurements was similar to the value observed by TEM. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2020 , 137, 48258.     

Effect of Compatibilizer Type on Properties of 70:30 Polyamide 6/Polypropylene/MMT Nanocomposites

PA6/PP nanocomposites with either polyethylene octene elastomer grafted maleic anhydride (POEgMAH) or PP grafted maleic anhydride (PPgMAH) as compatibilizer were prepared using co-rotating twin-screw extruder followed by injection molding. The mechanical and microstructural properties of the composites were investigated by means of tensile, flexural, and impact testing and by scanning electron microscopy (SEM). X-ray diffraction (XRD) was used to characterize the formation of nanocomposites. The result indicated that the miscibility of PA6/PP nanocomposites was improved with the addition of POEgMAH and PPgMAH. The impact strength of PA6/PP nanocomposite with POEgMAH increased about 5 times higher than uncompatibilized composite. Increment in tensile properties was observed when PPgMAH was used as compatibilizer. XRD results revealed that PA6/PP nanocomposites were successfully formed. Uniform dispersion of PP in matrix were observed through SEM, which showed the improvement of the compatibility between polymers.     

Preparation and properties of polypropylene/org-attapulgite nanocomposites

Polypropylene (PP)/org-attapulgite (ATP) nanocomposites were prepared by melt blending in a mixer apparatus. Org-attapulgite was attained by silane coupling agent modification first and then graft-polymerization with butyl acrylate. Scanning electron microscopy (SEM) and transmission electron microscopy (TEM) were used to assess the clay morphology and the dispersion of the org-attapulgite, respectively. The changes of crystalline structure for PP nanocomposites were characterized by X-ray diffraction (XRD). The mechanical properties of PP/attapulgite nanocomposites were studied through tensile and impact tests. The thermal and dynamic mechanical properties were characterized by differential scanning calorimetry (DSC) and dynamic mechanical analysis (DMA). The strength and stiffness of PP/org-ATP nanocomposites were both improved significantly in the presence of organic attapulgite. In addition, the incorporation of org-ATP also gave rise to an increase of the storage modulus and the changes of the glass transition temperature for PP composites. TEM and XRD results revealed the addition of attapulgite did not change the crystal structure of PP, however org-attapulgite acted as nucleating agents for the crystallization of PP.     

Compatibilizing effect of maleated polypropylene on the mechanical properties and morphology of injection molded polyamide 6/polypropylene/organoclay nanocomposites

Polyamide 6/polypropylene (PA6/PP=70/30 parts) blends containing 4 phr (parts per hundred resin) of organophilic modified montmorillonite (organoclay) were prepared using twin screw extruder followed by injection molding. Maleated polypropylene (MAH-g-PP) was used to compatibilize the blend system. The mechanical properties of PA6/PP nanocomposites were studied through tensile and flexural tests. Scanning electron microscopy (SEM) and transmission electron microscopy (TEM) were used to assess the fracture surface morphology and the dispersion of the organoclay, respectively. X-ray diffraction (XRD) was used to characterize the formation of nanocomposites. The thermal properties were characterized by using differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA). The dynamic mechanical properties of PA6/PP nanocomposites were analyzed by using dynamic mechanical thermal analyzer (DMTA). The strength and stiffness of PA6/PP nanocomposites were improved significantly in the presence of MAH-g-PP. This has been attributed to the synergistic effect of organoclay and MAH-g-PP. The MAH-g-PP compatibilized PA6/PP nanocomposites showed a homogeneous morphology supporting the compatibility improvement between PA6, PP and organoclay. TEM and XRD results revealed the formation of nanocomposites as the organoclay was intercalated and exfoliated. A possible chemical interaction between PA6, PP, organophilic modified montmorillonite and MAH-g-PP was proposed based on the experimental work.     

Morphological,mechanical, and thermal features of PMMA nanocomposites containing two‐dimensional Co–Al layered double hydroxide

The focus of the current study is to investigate the influence of Co–Al layered double hydroxide (LDH) on the morphological, thermal, and mechanical features of poly(methyl methacrylate) (PMMA)‐based nanocomposites. Sodium dodecyl sulfate modified Co–Al LDH was synthesized by single step coagulation method. The PMMA nanocomposites containing different loadings of nanofiller (1–7 wt %) and polystyrene‐grafted maleic anhydride compatibilizer (5 wt %) were melt intercalated via twin screw extruder and later subjected to injection molding to prepare mechanical testing samples. The different properties of PMMA nanocomposites were studied by using XRD, TEM, FTIR, DSC, TGA, tensile, flexural, impact, and flammability analysis. The result of XRD analysis suggested the exfoliated morphology of the nanocomposite while the TEM demonstrated the intercalated structure at higher loading of LDH. The thermal characterization results revealed that thermal properties were improved by the addition of Co–Al LDH, whereas the flammability test exposed that dripping was minimum at 7 wt % loading. The mechanical properties exhibited that optimum results were obtained at 1 wt % loading of Co–Al LDH. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018 , 135, 45774.