Relations between morphology and micromechanical properties of alpha, beta and gamma phases of iPP

Šlouf, Miroslav; Pavlová, Ewa; Krejčíková, Sabina; Ostafinska, Aleksandra; Zhigunov, Alexander; Krzyžánek, Vladislav; Sowiński, Przemysław; Piórkowska, Ewa

doi:10.1016/j.polymertesting.2018.03.039

Cited by 36 publications

(32 citation statements)

References 69 publications

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“…Due to the approximate nature of Tabor's and Struik's relations, the numerical constants in Equation 4 can vary in relatively broad range. However, the direct proportionality among the four quantities (E ∝ Y ∝ H ∝ v c ) holds usually very well for given semicrystalline polymer as evidenced in numerous previous studies (Martinez-Salazar et al, 1988;Balta-Calleja and Fakirov, 2000;Flores et al, 2009Flores et al, , 2011Slouf et al, 2015Slouf et al, , 2018.…”

Section: Micromechanical Propertiesmentioning

confidence: 66%

“…In Equations 12-13 above, F max is maximum loading force, A p (h c ) is the projected area of the indentation (which is a function of the contact depth (h c ) as described elsewhere (Oliver and Pharr, 1992;Slouf et al, 2018), and S = dF/dh denotes stiffness defined as the slope at the beginning of the unloading curve (see Figure 1). The indentation modulus (E IT ) was calculated from reduced modulus (E r ) using relation 1/E…”

Section: Micromechanical Properties: Microindentation Hardness Testingmentioning

confidence: 99%

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Monitoring of Morphology and Properties During Preparation of PCL/PLA Microfibrillar Composites With Organophilic Montmorillonite

et al. 2020

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Biodegradable microfibrillar composites PCL/PLA/C15, where PCL is poly(ε-caprolactone), PLA is poly(lactic acid), and C15 is organophilic montmorillonite, have been prepared. Microindentation hardness testing was employed in monitoring the gradual improvement of PCL stiffness due to PLA addition, C15 addition, flow-induced orientation, and changing crystallinity throughout the whole preparation process. Neat PCL after extrusion and injection molding was quite soft, but the stiffness of the material increased after melt-blending with 20 wt.% of PLA, after the addition of 2 wt.% of C15, and after the preparation of the final microfibrillar composite. The indentation modulus and indentation hardness of all intermediate products and the final PCL/PLA/C15 microfibrillar composite were associated not only with the composition and morphology but also with the crystallinity of both components. The modulus of the final PCL/PLA/C15 composite was almost two times higher in comparison with the original PCL matrix.

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Section: Micromechanical Propertiesmentioning

confidence: 66%

Section: Micromechanical Properties: Microindentation Hardness Testingmentioning

confidence: 99%

Monitoring of Morphology and Properties During Preparation of PCL/PLA Microfibrillar Composites With Organophilic Montmorillonite

et al. 2020

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“…The dependency of mechanical properties of PP on the DoC and cooling rate was studied in refs. . These data, compared together in ref.…”

Section: Introductionmentioning

confidence: 82%

Interface strength of glass fibers in polypropylene: Dependence on the cooling rate and the degree of crystallinity

et al. 2019

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The article experimentally investigates the interface strength of glass fibers in polypropylene (PP) with two different levels of crystallinity. The different degrees of crystallinity, 46.6% and 52.5%, were achieved using fast (quenching, ~4500°C/min) and slow (~2°C/min) cooling, respectively, during production of the PP film. The degree of crystallinity was measured using the differential scanning calorimetry. The mechanical properties of the films were characterized with the dynamic mechanical analysis and with a tensile test on Deben micro‐tester. Interfacial shear strength (IFSS) of glass fiber/PP was determined using fiber fragmentation test. Interfacial normal strength (IFNS) was determined using inverse identification based on finite‐element modeling of transverse tensile loading of a single fiber (Deben micro‐tester with digital image correlation‐based observation of the debonding). The measurements have confirmed the expected trend in mechanical properties of the film: increase of the storage and Young's moduli (room temperature) with the increase of degree of crystallinity, accompanied by the decrease in the loss modulus and tan δ. Interfacial strength followed the trend of the PP stiffness: both the IFSS and IFNS values for the PP with high crystallinity (slow cooling) are three (IFSS) and four (IFNS) times higher than those for the low crystallinity (fast cooling) case.

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“…Final F-h curves (where F is the loading force and h is the penetration depth) were employed in the calculation of four micromechanical properties: indentation hardness (H IT ), indentation modulus (E IT ), indentation creep (C IT ), and the elastic part of the indentation work (η IT ). All calculations were performed within the original software coming with the indenter (Indentation 5.18, CSM Instruments, Switzerland), according to the theory of Oliver and Pharr (1992); the details about the calculation of C IT and η IT were described elsewhere (Herrman, 2011;Slouf et al, 2018).…”

Section: Micro-indentation Hardness Testingmentioning

confidence: 99%

Structure Characterization and Biodegradation Rate of Poly(ε-caprolactone)/Starch Blends

et al. 2020

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The present paper focuses on the effects of blending poly (ε-caprolactone) (PCL) with thermoplastic starch (TPS) on the final biodegradation rate of PCL/TPS blends, emphasizing the type of environment in which biodegradation takes place. The blends were prepared by melt-mixing the components before a two-step processing procedure, which strongly affects the degree of plasticization and therefore the final material morphology, as was detailed in the previous work, was used for the thermoplastic starch. The concentration row of pure PCL over PCL/TPS blends to pure TPS was analyzed for biodegradation in two different environments (compost and soil), as well as from a morphological, thermomechanical, rheological, and mechanical point of view. The morphology of all the samples was studied before and after biodegradation. The biodegradation rate of the materials was expressed as the percentage of carbon mineralization, and significant changes, especially after exposure in soil, were recorded. The crystallinity of the measured samples indicated that the addition of thermoplastic starch has a negligible effect on PCL-crystallization. The blend with 70% of TPS and a co-continuous morphology demonstrated very fast biodegradation, with the initial rate almost identical to pure TPS in both environments while the 30% TPS blend exhibited particle morphology of the starch phase in the PCL matrix, which probably resulted in a dominant effect of the matrix on the biodegradation course. Moreover, some molecular interaction between PCL and TPS, as well as differences in flow and mechanical behavior of the blends, was determined.

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Relations between morphology and micromechanical properties of alpha, beta and gamma phases of iPP

Cited by 36 publications

References 69 publications

Monitoring of Morphology and Properties During Preparation of PCL/PLA Microfibrillar Composites With Organophilic Montmorillonite

Monitoring of Morphology and Properties During Preparation of PCL/PLA Microfibrillar Composites With Organophilic Montmorillonite

Interface strength of glass fibers in polypropylene: Dependence on the cooling rate and the degree of crystallinity

Structure Characterization and Biodegradation Rate of Poly(ε-caprolactone)/Starch Blends

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