Reinforcement of elastomeric polypropylene by nanoclay fillers

Vu, Yen; Rajan, Guru S.; Mark, J. E.; Myers, Charles L.

doi:10.1002/pi.1493

Cited by 25 publications

(21 citation statements)

References 87 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…[5][6][7][8][9]11,67,68 According to Deshmane et al, 10 the nucleating effect of MMT on polypropylene is high, whereas polyethylene remains almost unaffected. The addition of 4% MMT to polypropylene reduces the spherulite diameter from 210 to 14 μm, whereas the spherulite size of polyethylene remains unchanged.…”

Section: Resultsmentioning

confidence: 99%

Properties and Semicrystalline Structure Evolution of Polypropylene/Montmorillonite Nanocomposites under Mechanical Load

et al. 2011

View full text Add to dashboard Cite

Small-angle X-ray scattering (SAXS) monitors tensile and load-cycling tests of metallocene isotactic polypropylene (PP), a blend of PP and montmorillonite (MMT), and two block copolymer compatibilized PP/MMT nanocomposites. Mechanical properties of the materials are similar, but the semicrystalline nanostructure of the PP differs. This is explained by a nucleation effect of the MMT. Competitive crystal growth diminishes crystallite sizes. The reinforcing effect of the MMT filler appears consumed by weakening the PP matrix. Decays of mechanical and nanostructure response in dynamic load cycling indicate materials fatigue. Lifetimes describe the reinforcing and weakening effects. Addition of 3% MMT halves the fortifying effect of the PP nanostructure. A net gain of reinforcement (11%) is observed with the highly compatibilized composite in which the strength of the semicrystalline PP is reduced to 25%. Other results concern the evolution of Strobl's block structure and void formation during tensile loading.

show abstract

Section: Resultsmentioning

confidence: 99%

Properties and Semicrystalline Structure Evolution of Polypropylene/Montmorillonite Nanocomposites under Mechanical Load

et al. 2011

View full text Add to dashboard Cite

show abstract

“…Some authors claim that the disappearance of the silicate reflection after processing is accompanied by complete exfoliation. [11][12][13][22][23][24][25][26][27][28] Other researchers, however, showed that this is definitely not the case and an intercalated structure was also observed when the silicate reflection was absent from the XRD trace. [29][30][31] In his excellent paper, Vaia and Liu [32] analyzed the factors influencing XRD traces and pointed out the difficulties of quantitative or even qualitative analysis of nanocomposite structures.…”

Section: Introductionmentioning

confidence: 91%

“…[8][9][10][11][12][13] However, to really utilize all the potential advantages of polymer/layered silicate nanocomposites, the silicate must be exfoliated to a large extent into individual layers. For optimum performance the platelets should be distributed uniformly in the polymer matrix with an orientation parallel to the external load and they should strongly adhere to the polymer for efficient stress transfer.…”

Section: Introductionmentioning

confidence: 99%

“…with X-ray diffraction (XRD) and transmission electron microscopy (TEM). [4][5][6][11][12][13][15][16][17][18][19][20][21][22][23][24][25][26][27][28][29][30] Both methods have several advantages, but a few drawbacks as well. XRD is relatively easy to use and the characteristic reflection of the silicate in the 2y range below 108 indicates changes in its gallery structure very well.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Morphology Characterization of PP/Clay Nanocomposites Across the Length Scales of the Structural Architecture

Százdi

Ábrányi

Pukánszky

et al. 2006

Macro Materials & Eng

View full text Add to dashboard Cite

Summary: The structure and rheological properties of a large number of layered silicate poly(propylene) nanocomposites were studied with widely varying compositions. Morphology characterization at different length scales was achieved by SEM, TEM, and XRD. Rheological measurements supplied additional information about structure. The results showed that these materials possess a very complex structural architecture. The introduction of functionalized polymer decreased the size of the original clay particles and improved their interaction with the polymer matrix. However, relatively large silicate particles were found also in composite samples yielding XRD traces without silicate reflection. XRD supplies information of limited value if the amount of silicate is low, the gallery distance of the stacks is large or their regularity is limited. On the other hand, XRD indicates intercalation well. Although exfoliated individual layers can be detected by TEM, the method cannot be used to draw general conclusions about the structure of layered silicate nanocomposites because of statistical sampling and bias. A large number of individual layers, i.e. large extent of exfoliation, led to the formation of a silicate network structure, which can be detected very sensitively by Cole‐Cole plots of dynamic viscosity. We found that all four morphological entities (particles, intercalated stacks, individual layers, network) may be present simultaneously in the composites. The presence and relative amount must definitely influence composite properties. However, currently used experimental protocols do not supply sufficient information even to estimate the relative influence as well as interplay among different structural features quantitatively. We may conclude, however, that XRD and TEM alone are not sufficient for the characterization of nanocomposites with a complex structure.

show abstract

“…Recent reviews summarize [3–6] that modifications of the MMT are predominantly focusing on an improvement of the compatibility between the clay and the polyolefin. What is often not taken into account is, that many phyllosilicates nucleate [7–14] PP extremely well. An altered nucleation may change the resulting semicrystalline structure considerably [15–19].…”

Section: Introductionmentioning

confidence: 99%

Studying nanostructure gradients in injection-molded polypropylene/montmorillonite composites by microbeam small-angle x-ray scattering

Stribeck

Schneider

Zeinolebadi³

et al. 2014

Science and Technology of Advanced Materials

View full text Add to dashboard Cite

The core–shell structure in oriented cylindrical rods of polypropylene (PP) and nanoclay composites (NCs) from PP and montmorillonite (MMT) is studied by microbeam small-angle x-ray scattering (SAXS). The structure of neat PP is almost homogeneous across the rod showing regular semicrystalline stacks. In the NCs the discrete SAXS of arranged crystalline PP domains is limited to a skin zone of 300 μm thickness. Even there only frozen-in primary lamellae are detected. The core of the NCs is dominated by diffuse scattering from crystalline domains placed at random. The SAXS of the MMT flakes exhibits a complex skin–core gradient. Both the direction of the symmetry axis and the apparent perfection of flake-orientation are varying. Thus there is no local fiber symmetry, and the structure gradient cannot be reconstructed from a scan across the full rod. To overcome the problem the rods are machined. Scans across the residual webs are performed. For the first time webs have been carved out in two principal directions. Comparison of the corresponding two sets of SAXS patterns demonstrates the complexity of the MMT orientation. Close to the surface (< 1 mm) the flakes cling to the wall. The variation of the orientation distribution widths indicates the presence of both MMT flakes and grains. The grains have not been oriented in the flowing melt. An empirical equation is presented which describes the variation from skin to core of one component of the inclination angle of flake-shaped phyllosilicate filler particles.

show abstract

Reinforcement of elastomeric polypropylene by nanoclay fillers

Cited by 25 publications

References 87 publications

Properties and Semicrystalline Structure Evolution of Polypropylene/Montmorillonite Nanocomposites under Mechanical Load

Properties and Semicrystalline Structure Evolution of Polypropylene/Montmorillonite Nanocomposites under Mechanical Load

Morphology Characterization of PP/Clay Nanocomposites Across the Length Scales of the Structural Architecture

Studying nanostructure gradients in injection-molded polypropylene/montmorillonite composites by microbeam small-angle x-ray scattering

Contact Info

Product

Resources

About