The mechanism for fracture resistance in <i>β</i>‐nucleated isotactic polypropylene

Xu, Linli; Xu, Kai; Zhang, Xiuju; Liu, Feiyue; Chen, Mingcai

doi:10.1002/pat.1506

Cited by 17 publications

(18 citation statements)

References 50 publications

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“…When the β‐NA content was increased further, the impact strength decreased slowly. The variation trend of the impact strength as a function of the β‐NA content was similar to that in iPP/β‐NA systems . Obviously, the two β‐NAs were different in toughening PPR.…”

Section: Resultssupporting

confidence: 54%

Correlation between the fracture toughness and β‐crystal fraction in a β‐nucleated propylene‐based propylene–ethylene random copolymer

Zhang

Liu

Jiang

et al. 2015

J of Applied Polymer Sci

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Propylene‐based propylene–ethylene random copolymer (PPR) has been widely used in the production of hot‐water pipes. To further improve its toughness and thermal resistance, β‐nucleating agents (β‐NAs) are frequently incorporated. In this study, PPR containing 5.6 mol % ethylene units was modified by two kinds of β‐NAs, that is, calcium pimelate and N,N′‐dicyclohexylterephthalamide. The notched Izod impact strength of PPR increased with the addition of the β‐NAs. Drastically different toughening effects were found between the two β‐NAs. The structure of PPR with and without a β‐NA was investigated by calorimetry, X‐ray diffraction, and thermomechanical analysis. The results indicated that the relative fraction of β crystals (kβ) in the injection‐molded specimens was determined by the type and content of β‐NA. The relationship between kβ and the impact toughness was summarized. A critical value for kβ (0.68) was identified for the brittle–ductile transition of PPR. PPR with β‐NA having a kβ greater than 0.68 displayed a higher impact strength than the other mixtures. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016, 133, 42930.

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Section: Resultssupporting

confidence: 54%

Correlation between the fracture toughness and β‐crystal fraction in a β‐nucleated propylene‐based propylene–ethylene random copolymer

Zhang

Liu

Jiang

et al. 2015

J of Applied Polymer Sci

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“…Addition of selective b-nucleating agents, which are generally crystallizable organic compounds with low molecular weight (e.g., quinacridone dye, triphenodithiazine, and pimelic acid), is the common method to obtain high b-phase content in iPP [20,22,23,26,27,30].…”

Section: Introductionmentioning

confidence: 99%

Morphology and properties of highly filled iPP/TiO₂ nanocomposites

Zohrevand

Ajji

Mighri

2013

Polymer Engineering & Sci

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Nanocomposites based on isotactic polypropylene (iPP) and titanium dioxide (TiO 2 ) nanoparticle containing 1-15 vol% (4.6-45.5 wt%) of the nanoparticle were prepared by the melt blending process. The effect of an anhydride-modified polypropylene as a compatibilizer on dispersion of TiO 2 nanoparticles was assessed using SEM. TGA and DSC analysis were performed to study the thermal properties of the nanocomposites. Crystalline structures of iPP in the presence of TiO 2 were analyzed by XRD. Mechanical properties of the nanoparticles were measured and a micromechanical analysis was applied to quantify interface interaction between the polymer and particle. SEM results revealed improvement of TiO 2 particle dispersion by adding the compatibilizer. It was shown that the thermal stability and crystalline structure of the nanocomposite are significantly affected by the state of particle dispersion. TiO 2 nanoparticles were shown to be strong b-nucleating agents for iPP, especially at concentrations less than 5 vol%. Presence of the b-structure crystals reduced the elastic modulus and yield strength of the nanocomposites. Micromechanical analysis showed enhanced interaction between organic and inorganic phases of the compatibilized nanocomposites. POLYM. ENG. SCI., 54:874-886, 2014.

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“…As can be seen from Fig. , the plastic deformation region (right area of the dotted lines) of PP‐A is larger than PP‐B, which is believed to be in direct proportion to the level of impact strength . Moreover, it can be observed from Fig.…”

Section: Resultsmentioning

confidence: 73%

Morphology and mechanical behavior of isotactic polypropylene with different stereo-defect distribution in injection molding

Peng

Wang

Gai

et al. 2014

Polym. Adv. Technol.

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Large amount of work has been published on the isotacticity-properties relationship of isotactic polypropylene (iPP). However, the stereo-defect distribution dependence of morphology and mechanical properties of iPP injection molding samples is still not clear. In this study, two different isotactic polypropylene (iPP) resins (PP-A and PP-B) with similar average isotacticity but different stereo-defect distribution were selected to investigate the morphology evolution and mechanical properties (tensile and notching) of their injection molding samples using differential scanning calorimetry (DSC), dynamic mechanical analysis (DMA), 2D wide angle X-ray diffraction (2D-WAXD), and scanning electron microscope (SEM). The results of DMA showed that the molecular movement ability of PP-A (with less uniform distribution of stereo-defect) was stronger than that of PP-B, meanwhile the analysis of DSC and SEM suggested that after injection molding, smaller spherullites, and crystals with higher perfection had formed in the specimens of PP-A. The resulting of tensile properties of PP-A were found to be better than that of PP-B. The results of morphology evolution by SEM observation and 2D-WAXD showed that PP-A is more likely to occur interspherulite deformation and can disperse the tensile stress more efficiently, and therefore, its crystal structure can withstand a greater force when tensile stress is applied. On the other hand, PP-B has larger spherulites and boundaries, and low perfection of lamellaes, and the intraspherulte deformation tend to take place. It is easier for the crystal of PP-B to be broken up and reoriented along the tensile direction.

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The mechanism for fracture resistance in β‐nucleated isotactic polypropylene

Cited by 17 publications

References 50 publications

Correlation between the fracture toughness and β‐crystal fraction in a β‐nucleated propylene‐based propylene–ethylene random copolymer

Correlation between the fracture toughness and β‐crystal fraction in a β‐nucleated propylene‐based propylene–ethylene random copolymer

Morphology and properties of highly filled iPP/TiO₂ nanocomposites

Morphology and mechanical behavior of isotactic polypropylene with different stereo-defect distribution in injection molding

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The mechanism for fracture resistance in β‐nucleated isotactic polypropylene

Cited by 17 publications

References 50 publications

Correlation between the fracture toughness and β‐crystal fraction in a β‐nucleated propylene‐based propylene–ethylene random copolymer

Correlation between the fracture toughness and β‐crystal fraction in a β‐nucleated propylene‐based propylene–ethylene random copolymer

Morphology and properties of highly filled iPP/TiO2 nanocomposites

Morphology and mechanical behavior of isotactic polypropylene with different stereo-defect distribution in injection molding

Contact Info

Product

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About

Morphology and properties of highly filled iPP/TiO₂ nanocomposites