Polypropylene/organoclay nanocomposites prepared using a Laboratory Mixing Extruder (LME): crystallization, thermal stability and dynamic mechanical properties

This study describes the reinforcement effect of surface modified mullite fibers on the crystallization, thermal stability, and mechanical properties of polypropylene (PP). The nanocomposites were developed using polypropylene-grafted-maleic anhydride (PP-g-MA) as compatibilizer with different weight ratios (0.5, 1.0, 1.5, 2.5, 5.0, and 10.0 wt %) of amine functionalized mullite fibers (AMUF) via solution blending method. Chemical grafting of AMUF with PP-g-MA resulted in enhanced filler dispersion in the polymer as well as effective filler-polymer interactions. The dispersion of nanofiller in the polymer matrix was identified using scanning electron microscopy (SEM) elemental mapping and transmission electron microscopy (TEM) analysis. AMUF increased the Young's modulus of PP in the nanocomposites up to a 5 wt % filler content, however, at 10 wt % loading, a decrease in the modulus resulted due to agglomeration of AMUF. The impact strength of PP increased simultaneously with the modulus as a function of AMUF content (up to 5 wt %). The mechanical properties of PP-AMUF nanocomposites exhibited improved thermal performance as compared to pure PP matrix, thus, confirming the overall potential of the generated composites for a variety of structural applications. The mechanical properties of 5 wt % of AMUF filled PP nanocomposite were also compared with PP nanocomposites generated with unmodified MUF and the results confirmed superior mechanical properties on incorporation of modified filler. V C 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016, 133, 43725.

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“…The percentage of crystallinity value of PP nanocomposites was calculated by the following eq. and the values are presented in Table

normalX normalc true(% true) = \frac{Δ H_{m}}{true(1 - f true) Δ H_{m}^{o}} \times 100

…”

Section: Resultsmentioning

confidence: 99%

Crystallization, mechanical, and fracture behavior of mullite fiber‐reinforced polypropylene nanocomposites

Vengatesan¹,

Singh²,

Pillai³

et al. 2016

J of Applied Polymer Sci

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“…Depending on the molecular structure (such as molecular weight and its distribution, isotacticity and defect distribution, etc.) and the processing conditions applied, iPP can exhibit plentiful crystalline structures and aggregation structures, resulting in rather versatile physical properties (such as mechanical, barrier, optical, thermal properties) to meet the requirement of different applications . Up to now, three crystalline structures of iPP are known, including the monoclinic α‐form, the trigonal β‐form, and the triclinic γ‐form .…”

Section: Introductionmentioning

confidence: 99%

Investigation on the Tensile Behavior and Morphology Evolution of Isotactic Polypropylene Films Polymerized with Different Ziegler-Natta Catalysts

Kang

Xiong

et al. 2015

Adv. Polym. Technol.

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Stereodefect distribution is very important in determining the morphology and properties of isotactic polypropylene (iPP). In this study, two iPPs (PP-A and PP-B) with different uniformities of stereodefect distribution were prepared. The tensile behavior and morphology evolution of their cast films were studied. The morphology study of the cast films showed that compared with PP-B, PP-A with less uniform distribution of stereodefects has smaller spherulites and spheruilitic boundaries and higher degree of crystallinity. In uniaxial tensile measurements, PP-A exhibited higher yield strength and lower elongation at break. When strain was 500%, PP-A exhibits totally transparent appearance and highly oriented structures without cavities, whereas PP-B shows opaque appearance and mass of both nanometer-and micrometer-sized cavities. Moreover, calculation of rigid amorphous fraction (RAF) indicated that PP-B cast film has a higher amount of RAF, which might be the reason for the different morphology evolutions and tensile behaviors of the samples. C 2015 Wiley Periodicals, Inc. Adv Polym Technol 201 , , 21573; View this article online at wileyonlinelibrary.com.

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“…The melting and crystallization thermograms of the materials are shown in Figure 8. The percentage crystallinity of the materials was calculated using the following equation, [49] , and the calorimetric values are given in Table 2.…”

Section: Resultsmentioning

confidence: 99%

Polypropylene/phosphazene nanotube nanocomposites: Thermal, mechanical, and flame retardation studies

Vengatesan

Singh

Devaraju

et al. 2020

J of Applied Polymer Sci

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In this study, flame retardant polypropylene (PP) nanocomposites with superior mechanical performance have been developed using amine‐functionalized phosphazene nanotubes (APZS, 1–10 wt%) through melt‐blending method. Polypropylene‐graft‐maleic anhydride was used as the compatibilizer to attain effective interaction between the nanofiller and the PP matrix. The characterization of amine‐functionalized phosphazene nanotubes (APZS) using solid‐state nuclear magnetic resonance (NMR), X‐ray photoelectron spectroscopy, X‐ray diffraction, fourier‐transform infrared (FTIR), and transmission electron microscopy indicated successful amine functionalization, though structural changes were observed as compared to the unfunctionalized nanotubes. Owing to the covalent polymer‐filler interfacial interactions and resulting in uniform filler dispersion, the nanocomposites exhibited significant enhancement in the tensile modulus up to 5 wt% APZS content (98% increment at 5 wt% content as compared to pure polymer). The addition of a small fraction of APZS (1 wt%) improved the impact strength of the nanocomposite by more than 180%. APZS acted as a weak nucleating agent for PP, thereby leading to enhanced degree of crystallinity (up to 5 wt% APZS content). The thermal stability of the nanocomposites was also enhanced with APZS content. The nanocomposites with 5 and 10 wt% APZS loading exhibited a V0 rating in UL‐94 test, indicating that APZS introduced a robust flame retardancy behavior in the PP nanocomposites. The limiting oxygen index values also confirmed the findings from the UL‐94 analysis. The developed nanocomposites exhibit high potential of use in a wide range of high temperature applications.

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Polypropylene/organoclay nanocomposites prepared using a Laboratory Mixing Extruder (LME): crystallization, thermal stability and dynamic mechanical properties

Cited by 18 publications

References 41 publications

Crystallization, mechanical, and fracture behavior of mullite fiber‐reinforced polypropylene nanocomposites

Crystallization, mechanical, and fracture behavior of mullite fiber‐reinforced polypropylene nanocomposites

Investigation on the Tensile Behavior and Morphology Evolution of Isotactic Polypropylene Films Polymerized with Different Ziegler-Natta Catalysts

Polypropylene/phosphazene nanotube nanocomposites: Thermal, mechanical, and flame retardation studies

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